Growing Table Grape Varieties for Subtropical Hawaii Using Organic Practices

Final report for FW21-378

Project Type: Farmer/Rancher
Funds awarded in 2021: $25,000.00
Projected End Date: 04/01/2023
Host Institution Award ID: G324-21-W8613
Grant Recipient: Kawanui Farm
Region: Western
State: Hawaii
Principal Investigator:
Gerry Herbert
Kawanui Farm
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Project Information


Although there have been many past attempts to grow table grapes in Hawaii, locally grown grapes are not commonly available for sale, nor are plants or the grower information necessary for growing grapes in the subtropics. There is great potential to find varieties that can be successfully grown by market growers and home producers adding a new nutritional food for Hawaii’s people, creating new growing information and a repository for grape scions, and developing an import substitution that will help diversify Hawaii’s agricultural base.

Question:  Can this project find the right grape varieties that will successfully grow and thrive using sustainable organic methods and consistently produce delicious grapes in the subtropics?  

Using a unique research model, that includes extensive investigation into the work of T.V. Munson, Joseph L. Fennel, Lon Rombough, and Francisco Wallington-Linares, the project will choose 35 varieties available on the USDA GRIN Grape Repository at UC Davis that were successfully bred in semi-tropical and subtropical regions, have wild grape genetics in their parent lines and have proven potential in Southern Texas, Florida, Puerto Rico and the Caribbean.  Using that information, and building upon the work of Ken Love and “Grapes for Tropical Hawaii,” this project will vet these varieties at Kawanui Farm in Kona, Hawaii. 

 In 2021, we reached out to grower groups across the State and created a stakeholder group of 110 growers from all Islands that were interested in following our bunch grape research and education project.  Their location and emails are now in our WIX website list serve system.   Then, instead of 3 times per year, we created and sent our stakeholder group a quarterly Seasonal Blog that shared pertinent research information, identified new bunch grape Readings & Resources, and created and shared 10 on-farm videos on various grape subjects of interest.   These educational materials were also posted on our farm website each quarter.  Every week,  we continue writing our booklet “Growing Table Grapes in Subtropical Hawaii Using Organic Methods,” that we will be printing, sending out to interested Stakeholders,  and posting on our farm website in March 2023.  We continue to post current photos of grape varieties and practices etc. a few times a month on Instagram #grapesforhawaii.   At the end of this first year, that saw rainfall increase from 40 to 92" per year (for the past 3 years) we continue to work on creating a repository of successful bunch grape varieties that will continue to be vetted. A limited number of scions of successful varieties will be made available to stakeholders March 2023.  We are ending the first year of our SARE research and education project with 14 very promising varieties out of 56 we have vetted since 2015.  This year 2021-22 our weather pattern has returned to the more familiar wet/dry season, which should greatly increase fruit production that we will taste this summer, many varieties for the first time! All Blogs, photos, videos, and resource documents are available on  

Only Educational Objective Three has been modified and approved.  

Final Report:  Our Stakeholder group grew from 110 to 188 Hawaii growers during the 2 year grant period.  We created and posted 9 Blogs, 22 instructional videos, regularly posted new photos of grapes & vineyards, regular instagram postings #grapesforhawaii, grape resources, and Gerry's research notes were all posted on our Kawanui Farm website.  We wrote and published 100 copies of our 56 page Booklet "Growing Grapes in Subtropical Hawaii Using Organic Practices" summarizing our work and mailed copies to all interested Stakeholders by the end of March 2023.  We created a new Grape Homepage on our farm website that included a summary of our SARE research project and a downloadable copy of our Grape Booklet.  We ended the project by writing a summary of the project that was published in the College of Tropical Agriculture and Human Resources Hanai'Ai Quarterly Newsletter of the University of Hawaii.  Another summary article was sent to the Hawaii Tropical Fruit Growers Association Members, and Gerry was interviewed by our Island Newspaper West Hawaii Today in a full page article.  When this report is finished and approved, we will send a copy of the report along with the Booklet link, to everyone who initially wrote us a Letter of Support.  We also shared scion wood with growers who had been following this project in West Hawaii and we will expand this in the future as our grapes mature.  We created an online Grower Survey that was shared with our Stakeholders with 57 growers responding.  

Our SARE Farmer/Rancher Grant is at its end, but our grape research and education initiative is not finished. Now that COVID is beginning to wane in the Hawaiian Islands, we are looking forward to creating 1 or 2 on-farm workshops in 2023-24.  One on harvesting and culinary uses of grapes in the summer of 2023, and a Grapes Pruning Workshop in February 2024.  We will continue to Blog, Video, and post on our farm website updating our Stakeholders.  We are indeed grateful for this research and education opportunity.  The SARE Program is a valuable and unique opportunity for farmers to dive deeply into one of their passions, and then share the results with other growers across their regional area.  Here in Hawaii, we are very disconnected, due to the vast distances between Islands, but this project brought growers together from every Island in Hawaii and in Chapter 7 of our Booklet we will discuss all the ways local growers can get started doing their own research.  Once again Mahalo Nui for the opportunity to expand the diversity of our regional community food systems using organic practices. Chapter 7 Vetting Varieties

Project Objectives:

Grape Survivors 2015-2022 Rainfall Chart Kawanui Farm 2003RESEARCH Objectives:GrowingTableGrapes_Web

Project site:  Kawanui Farm is located at the 1,450 foot elevation on the western side of the Hualalai Volcano in the Kona District of Hawaii Island. The soil composition is rich basalt volcanic ash and the average rainfall is 42 inches but we have measured a low of 23 inches in 2003 and high of 123 inches in 2004.  2020 is looking like rainfall totals will be more than 100 inches. The farm faces southwest and the land is gently sloping. The vineyards use the modified Geneva Curtain style of grape trellis that has been sustainably built using old growth redwood from recycled water tanks. To my knowledge we are the first modern age people to live on this land, so the soils have always been used organically.

Final Report:  Climate change has come to the Hawaiian Islands.  Our rainfall from 2019-2021 was almost 100 inches each year without our usual 6-month dry season which is very unusual.  Coincidently, the timing coincided with our SARE project, and created some difficulties for grape varieties that don't like a wet and cloudy climate year round. However, it turned out, it created an extreme "vetting" situation and because many of the varieties that had some subtropical genetics in their parent lines were able to survive and produce tasty grapes.  2022 and 2023 so far have been more "normal."  More sun and more dry days, and a more distinct wet/dry season....conditions that grapes favor.   An electronic copy of our Booklet is attached above that will provide more details.  

Objective One:  Observe and record information for each of the fifty six grape varieties that have been vetted in the five vineyards.  (Observation Criteria in" Other Documents") Research findings year 1:  Gerry has over 100 pages of observations and notes from 2015-2022 following the Observation Criteria in Other Documents.  A summary of that information will be included here in attached documents.  A representative selection of notes and photos will be made into documents that will be included in this report.  See Log Book and Red Folder Summary and Photos documents (attached) Research findings year 2: Gerry has continued through year 2 to record observations in his Log Book.  We received 16 new grape variety scions from UC Davis in 2020 and out of that group only 5 varieties grew well, 2 of those we have not yet tasted.  Grape varieties with some subtropical (wild) parent genetics were best suited to Hawaii's unique climate and soil conditions.  We have wild chickens that decided they liked ripe grapes also!  Gerry chose grape clusters that were out of their reach and bagged them as they turned color and this solved the problem.  Grape varieties that were slow to get started in the Spring, were more subject to Chinese Beetle damage, but some of those slower varieties caught up and were able to grow a good amount of leaf coverage to support flowering and fruiting.  Varieties that grew quickly in the Spring and/or had the subtropical wild trait of white "felting" on the underside of the leaf were ignored by the Chinese Beetles.  Each of the 12 varieties grow at different rates, have different structure and leaf patterns, different timing for flowering and fruiting, and different cluster and grape sizes.   They all received the same organic implements and respond well to additions of on-farm compost, wood ash and bone meal.  All vineyards are covered with a thick layer of leaves recycled from trees and plants growing on the farm.  Mulch helped to preserve moisture and cool the soil during dry periods, while breaking down and forming compost.  See Booklet Chapter 8 for detailed information on varieties. Chapter 8

Objective Two:  Research, observe, and document how best to prune and train each grape variety at the right time, with the right technique, the right amount of pruning, and create a dormancy period.  Research findings year 1:  The needed dormancy period for grapes was helped by a return to dry weather and cold nights.  All the leaves that had not already fallen were removed by hand by the end of December.   Right now (February 2022) Gerry is pruning all the vineyards and observing and documenting pruning by variety.  Two varieties began to bud out very early, at the end of January, and so they were pruned much earlier than we have ever pruned before, but each variety is different.  By the end of February all the grapes will be pruned and any scions will be planted out in the greenhouse.   Summary of observations will be included in this report.  (see Red Folder document and Blog #4 www/ for additional information on pruning) Research findings year 2:  Climate change is asking farmers to change their practices and respond to what our crops are telling us.  The 2022-2023 pruning season saw drier days and cooler nights, which facilitated a greater leaf drop from most of the varieties in November and December.  Something we had not seen in previous years. Gerry helped dormancy by removing the last leaves in early December.  Grapes began to bud out in January facilitating pruning that started in early February.  All varieties were pruned by first week of February.  Over the past 7 years of experimenting with various amounts of pruning, Gerry has discovered that in the subtropics, grape varieties need to be pruned yearly at 98% of the year's growth.  That may sound like a lot, but some varieties can grow stems up to 30 feet in length.  We continue to use the modified Geneva Double Curtain Trellis system (from Cornell) to maximize vine growth area.  This system has proven to be very successful.  More vine area means more leaves, more flowers and grape clusters.  See Booklet Chapters 5 and 6 for more details on Training and Pruning.

Objective Three:  Experiment with, observe, and document sustainable organic growing methods that will achieve optimum growth, plant health, and eventually excellent taste. No outside inputs will be used, instead on-farm nutrients will be recycled creating compost and mulching systems.  Research findings year 1:  We applied compost, bone meal/shells, wood ash, kelp, when the vines when needed during their growing season, not during their dormant period.  Now that spring has begun in the subtropics (this year it was the end of January 2021) we are watering and applying compost and kelp to awaken them, as they had been dry for three months.  We have kept a thick layer of mulch on the surface of all the vineyards to protect the soil and preserve moisture as the late fall and winter this year has been very sunny and dry with 1/2 to 1 inch of rain per month.  All varieties are given the same treatment, varieties that did not grow well in 2021 were removed and more promising varieties were planted in those spots.  Just because a variety did not do well here, is not a reflection on organic practices.  Low input sustainable systems are essential for future food production in Hawaii.  The 14 varieties that have survived and thrived indicate that some varieties of table grapes can be successfully grown in Hawaii, however we have not tasted all the varieties, hopefully that will happen this summer.  Taste will be the final component.  Research findings year 2:  We followed the same practices as outlined above in 2022-23.  Two varieties were removed due to poor performance, two are on probation, can't judge too quickly as some varieties are slow to get going, but then in the next year or so they become acclimatized and begin growing well.  Grapes don't like a lot of nitrogen, as that produces mostly vine and leaves to the detriment of flower and fruit production, so our compost which is highly diverse and well broken down, seems perfect for grape production.  We continued to recycle as mulch (composting in place) all the leaves from every tree that were cut back this year on the farm.  Mulch in the subtropics is essential as tropical sunlight and pounding rains can erode soil structure.  Recycling on-farm organic matter helps to create on-farm sustainability in the subtropics.  In Hawaii, we have so many invasive species that move around in organic matter and impact production that creating a closed loop of farm soil implements is essential.  The Little Fire Ant alone, necessitates this practice.  Organic systems work the best for the plants and for the food that is eaten by us humans.  See Chapter 4 in Booklet for more details.  

Objective Four:  Observe and record the effects of climate change on the grape varieties chosen for the vineyards. Research findings year 1:  There had been 3 years of constant rain (90+") during 2019, 2020, and 2021 in an area that "traditionally" has a 6 month wet 6 month dry season.  Also, the temperature  was well below normal, days and nights quite cool, and days cloudy.  The grapes all still grew, but some of the varieties died, the Chinese Beetles decimated others, and so this 3 year period was an extreme vetting process.  Of the 56 varieties 14 remain healthy and promising after 6 years.   The weather has returned to its normal wet/dry cycle in late 2021.  The winter nights have been cool down to 56 degrees.  Soils in Kona are very porous with good drainage, but the 3 years of rain depleted minerals even with a layer of mulch on the surface of the soil the soil has become a bit harder.  Because our volcanic ash soils have been organically managed for 24 years, Gerry knows they will come back from any loss of nutrients in 2019-2021.  We continue to apply additional farm grown compost, but it's important not to provide too much nutrition, as we don't the plants to be all leaf and vine.  Grapes are grown traditionally in drier hotter areas, and so many of them are right at home.  With these changes in climate we had poor fruit production last summer, and the grapes that did fruit had diminished taste.  Even with subtropical parent lines, many grape varieties cannot grow and produce well with constant rainfall, but luckily, there are very few areas of Hawai'i that have a 12 month rainy season.  Part of the vetting process, in today's climatic rollercoaster, will be to observe and find varieties that will weather these extremes and thrive.  Research Findings year 2: The weather and climate in the Central Pacific is changing.  As described above 2019-2021, rainfall increased from a normal 40" a year to almost 100" per year, with rainfall coming from a new direction, the Southwest.  Warm moist air moved northward from the equator toward the Hawaiian Islands driven by new wind patterns that we have not see in the last 50 years.  Grapes usually like dry and warm or hot weather, not wet and cloudy.  However, the unusual weather helped us vet varieties that could be tough and hardy in extremes which may become the norm. Other observations include increased invasive species that have decimated our avocado trees, Kona Coffee crop, and other trees and crops.  There are no grapes being grown on Hawaii Island so there are no grape diseases here yet, and the only pest has been the Chinese Beetle. We discovered that varieties with subtropical wild genetics (white felting on the back of the leaf) are a deterrent to the beetle.  In the Autumn when grape leaves would naturally fall in temperate climates, the Chinese Beetles come out helping us bring the grapes into dormancy.  In 2022-23, our wet/dry season has been somewhat more normal with more sunny days and dryness that the grapes prefer.   

Objective Five:  Taste and record the flavor profile of every grape variety.  Grapes produced in these systems must have excellent taste.  Research Findings year 1: Due to extreme rainfall and many varieties still young (including all he 2020 UC Davis scions), there was poor grape production last summer and we were unable to taste many of the varieties.  Of those we did taste, none of them were very sweet and the number of clusters was greatly diminished.  We expect all this to change in this summer's fruiting, as the weather has been dry and hot, exactly what grapes like.  Research Findings year 2:  Grapes do not start producing fruit until the third or fourth year, are in their prime in six to eight years, and then produce at that level for the next 100 years.  This summer, our twelve producing varieties in the five vineyards were between two and seven years old.  A few had good production like Tamiami (around 300 grapes clusters on 4 vines) but many of the varieties only were beginning to produce fruit.  We were able to taste nine of the twelve varieties and their flavor profiles are documented in Chapter 8. We made some excellent raisins with 5 of the varieties, with Tamiami being the best tasting.  All the varieties are seeded grapes, as they have a more deep and wide flavor profile, and the small seed in the raisin, after dehydrating the grapes had a tiny crunch that was acceptable.  We were able to produce juice from 6 of the varieties, that varied in sweetness and flavor.  A detailed description of each is found in Chapter 8 of the Booklet.  

We are looking forward to the next decade of production to expand our culinary production and we hope that many growers across the Hawaiian Islands will also be adding grapes to their garden or farm production.  The first grape, the Isabella, was thought to have come to the Hawaiian Islands in 1792, so it has taken 230 years for this research to get started.  We are grateful for this opportunity to be able to begin to research and grow this important addition to Hawaii's diet.  We are grateful and stand on the shoulders of those early grape breeders from Southern Florida, Texas, and Puerto Rico who made significant discoveries about growing grapes in subtropical environments.  These stories are outlined in the Introduction of the Booklet.  

Educational Objectives: 

Objective One:

Identify group of potential stakeholders statewide interested in learning to grow grapes.  Education year 1:  After reaching out to a list of grower organizations, a grower group of 110 stakeholders was identified statewide who are interested in learning to grow grapes.  All names are now part of our WIX website list serve.  This makes communication with the group easy when we send out our Shout-out and Blog, containing research information,  resource additions to the website, and new photos and videos.  We are pleased that so many people were interested.  Education year 2:  Our Stakeholder group grew this past year from 110 to 188.  Each of these growers signed up to receive our shoutouts informing them of new blogs, videos, and resources being added to our farm website.  We also answered every email sent to us and kept those in a Stakeholder file.  The group was diverse and all the Hawaiian Islands except Lanai were represented. About twenty people emailed us saying that had one variety of grape in their home garden but very few were happy with the production.  Temperate varieties are sold in Hawaii during the early Spring in a few nurseries,  usually hybrid seedless green or red varieties that never produce or grow well in the subtropics.  Link to Kawanui Farm website:    

Objective Two: Communicate ongoing research and educational information to stakeholder group that was identified in Objective One, in a short readable blog every four months for two years.  ( 6 blogs over 2 years) Education year 1:  By the end of March 2022, we will have posted 4 Blogs with interesting grape research information, links to new videos, photos, and resources. All Blogs are posted on  Education year 2:  We created an additional 5 Blogs this year for a total of 9 over 2 years, with additional shoutouts about interesting grape resources when we posted them.  As we added grape resources and/or reports to the website, which reflected Gerry's ongoing research notes, or other interesting grape resources we informed our Stakeholders.  We used Instagram #grapesforhawaii to post grape photos with short stories, and encouraged our Stakeholders to post any photos also.  We found that to be a difficult way to engage Stakeholders, as only a few people posted photos of their grapes in Hawaii. Link to Blogs:   

Objective Three: Host an on-farm or virtual Demonstration/Workshop for stakeholders in August 2021. Education year 1:  Due to COVID, Objective Three has been modified and approved.  Instead of one in-person workshop in year 1,  we created 12 short videos each one illustrating an aspect that would have been covered in the workshop.  All videos have been posted on our farm website on our youtube channel. Gerry has also hosted 2 "mini-workshops" here for a morning with a few interested stakeholders who live in our area of Hawaii island.  They received a farm tour, and talk story with Gerry about his research documents and findings.  We keep in contact with many of our stakeholders by email as they ask questions and make comments.  We have a mini-group that have had Vineyards in California and now live in Hawaii.  We have 4 stakeholders in the Kona area and one on Oahu that we are sharing scions with in March 2022.  Education year 2: Again, we were unable to host an in person gathering due to COVID and decided to create a new series of instructional videos which was approved by SARE.  In year 2 we added another 10 grape instructional videos for a total of  22 on- farm instructional videos, with Gerry talking in each one about some aspect of grape production in the subtropics.  These videos are posted on our Kawanui Farm website and are listed also as a Product.  Each of these videos covers some aspect of production and we discovered that shorter videos, smaller bites of information,  were more interesting to our Stakeholders.  COVID is just beginning to lessen here in the Islands, and we hope to have one or two Grape Workshops in 2023-2024.  One on Pruning in the Winter of 2024 and one on the Summer Harvest and culinary possibilities in the Summer of 2023.   Link to videos:   

Objective Four:  Host a second on-farm or virtual Demonstration/Workshop for stakeholders August 2022.  This Objective is for next summer.  We will need to evaluate where we are then with COVID.  Either we will make 10 more videos or have an in-person workshop.  In lieu of a Survey that would be given to workshop participants I thought of another way to fulfill that requirement.  IF we cannot have an in-person workshop in August 2022, we plan on reaching out to a group of 20 Stakeholders with the SARE Survey and ask them a few questions about our educational materials, were they effective, relevant, helpful, interesting, and compile the results.  I will submit the questions to SARE for approval.  Education year 2:  Objective Four follows what is written above.  We created more instructional videos for our Stakeholders.  We were able to figure out a way to gather feedback from our Stakeholder group statewide in an online Survey that was sent to everyone in February and March 2023, using the same format as the SARE in-person Survey.  We received approval from SARE after submitting the questions and format to Cayley.  Both the Excel Survey Results and Copy of the Survey Questions are attached.  We are pleased that 57 of our Stakeholders took the Survey who had been following our research and education program for the past 2 years, and we are pleased to see that so many of them learned new information that they will be applying or sharing with colleagues. SARE Survey for Grape StakeholdersSURVEY FOR OUR GRAPE STAKEHOLDERS(2023-04-09)

Objective Five: Write, publish, and mail a booklet “Growing Table Grapes in Subtropical Hawaii Using Organic Practices." Downloadable copy available on Kawanui Farm website.  Education year 1:  Once a week Gerry and I and sit down and write for a morning. We started writing the booklet last summer and we have written the Introduction and are on Chapter 6.  I have also been meeting with printers, because we would like this printed locally if possible, it will be a Spiral Bound plastic coated cover, with room for field notes at the back.  I think we are making good progress.  I would like to be finished by early next fall.  We need to wait until this coming summer of 2022 to actually taste many of the varieties that were planted years ago, and write up those chapters.   We bought our grape press and we are set to make juice, raisins, evaluate taste, etc.  Education year 2: We were able to finish writing and publish a 56 page Booklet that will inform Hawaii's Growers of the findings of our SARE grape research and education project from 2021-2023.  We were able to print 100 copies and mail them by March 31 to all Stakeholders who requested a copy.  We also mailed a copy to Western SARE c/o Bruna Irene Grimberg at Montana State University.  We also created a PDF for our website and sent a shoutout to all our Stakeholders informing them that they can read online or download.  This was an ambitious work, but a very important one to spread this research and education knowledge as widely as possible both within the State of Hawaii and any of the warmer regions of the US. GrowingTableGrapes_Web

Objective Six: Create a grape repository of successful varieties for Hawaii's growers. Education year 1:  We continue to vet varieties, and whittle down the weaker ones, and we are making scions available to a few stakeholders in our area this year 2022.  It is still our vision to offer scions of our best varieties ( there will be limited supply) to Stakeholders who are really interested in March 2023 along with our published booklet either mailed or downloadable on our farm website.   Education year 2:  In this past year, another 2 varieties were removed from the vineyards leaving 12 successful varieties out of the 58 trialed.  This year, we successfully shared scion wood and barefoot varieties with 8 growers on Hawaii Island.  In the future, we hope to be able to share our yearly scion wood variety list with our Stakeholders once a year and make these successful varieties available to some growers in the Hawaiian Islands.  Chapter 7 in our Booklet outlines all the possibilities for Hawaii's growers to start adding grapes to their farms or gardens. Chapter 7 Vetting Varieties



Gerry Timeline #1 21-22Gerry Timeline #2 22-23

There are no modifications to the timelines for Research or Education.  


Click linked name(s) to expand/collapse or show everyone's info
  • Ken Love - Technical Advisor
  • Nancy Redfeather (Educator)


Materials and methods:


Research Plan and Objectives 2021-2023

Objective One:  Observe and record information for each variety added to the four vineyards. 

Record observations in logs daily looking for varieties that will thrive in Hawaii. By “thrive” I mean they are tough and hardy, resistant to Hawaii’s pests and diseases, can withstand El Nino drought cycles and years of extreme rain like 2020, three months of volcanic eruptions, can grow well in organic systems with no outside inputs, and have an excellent taste profile. Detailed Observation Criteria attached in More Documents.

Fourteen new table grape varieties from the UC Davis Grape Repository were added to the vineyards in April 2020 and were specifically chosen from extensive research into the complex parent lines that had been bred by well known American breeders. (see Citations) Each variety had been successfully grown in semi-tropical and subtropical regions of Southern Florida, Southern Texas, the Caribbean, and Puerto Rico, and had wild grape genetics in their parent lines. These genetics create an “introduction” into this subtropical region. This research approach is new, unique, and I believe will produce lasting results. 

End of Year One:  Please see attached documents Grape Log & Red Folder Research, Grape Log Photos, and Red Folder Photos, Rainfall Chart, and Vineyard Winners!Grape Survivors 2015-2022Red Folder Research PhotosLog Book PhotosLog Book & Red Folder Research notesRainfall Chart Kawanui Farm 2003

End of Year Two:  See Grape Log and Red Folder Sheets of Research.  Grape Photos updated quarterly on farm website. Our Booklet is a summary of our observations and research findings. GrowingTableGrapes_WebFinal Summary of all varieties included in Chapter 8 of the Booklet. Chapter 8

Objective Two:  Research, observe, and document how best to prune and train each grape variety at the right time, with the right technique, the right amount of pruning, and create a dormancy period.

Some grapes produce best with “long-arm” pruning, some like “short-arm,” and some do best with spur pruning techniques. Grapes will be pruned once a year, and since we never have a frost, we will need to put them into a leafless period of dormancy from December to mid-February each year to achieve the best grape growth in the following year.   Pruning will be done in the mid-February. I will continue to experiment with pruning different amounts from all vines to arrive at the best % to be pruned from each variety. I will also record all training techniques for each variety in my uniquely modified Geneva Double Curtain system.  See More Documents for details and photos of the “Modified Geneva Double Curtain System.

End of Year One:  Please see Grape Blog March 2022, and 2 Pruning Videos March 2022.

End of Year Two: Summary of Year 2 Pruning & Training observations in Chapters 5 & 6 of Booklet. GrowingTableGrapes_Web

Objective Three:  Experiment with, observe, and document sustainable organic growing methods that will achieve optimum growth, plant health, and eventually excellent taste. No outside inputs will be used, instead on-farm nutrients will be recycled creating compost and mulch systems. 

For the past 50 years, I have been experimenting with organic growing methods first on my twenty acre farm in Mendocino County, California and later on my current farm in Kona, Hawaii. I graduated from UC Davis with a Science degree in International Agriculture Development (IAD) and had two majors in soil science and viticulture. I also worked at the Fetzer Winery for many years assessing brix levels for grapes during the crush and kept records on all fermenting tanks for the season. I have done extensive reading and application of organic methods both in temperate, Mediterranean,  and semi-tropical climates. I have been using organic methods of growing in my orchard and vegetable plots both in Mendocino and Hawaii. These organic systems will provide  essential plant nutrients and encourage deep rooting that will allow the grape varieties to withstand the climate changes that are already upon us. 

 On-farm nutrient recycling systems will include:

  1. Compost will be created using both nitrogen and carbon materials gathered from all areas of the farm. Using only on-farm inputs offers the best protection from the Little Fire Ant.
  2. Mulch will be created from organic farm materials recycled to preserve moisture and protect the soil from pounding rains and sun, creating a rich healthy system that feeds soil microorganisms and worm populations.
  3. On-farm wood is recycled through the home fireplace to make wood ash, an excellent addition to the soil.
  4. Bones from wild chickens, pigs, etc. will be processed through the fireplace and ground to create bone meal. 
  5. End of Year One:  Due to 3 years of rainfall we also began adding a soluble Kelp solution at the beginning of Spring 2022 to help replace micronutrients in the soil.  

          End of Year Two:  On-farm compost was added twice a year to all vineyards.  Other organic implements created on farm include wood ash, bone meal.  Leaves recycled from orchard trees were used in a thick layer as mulch to lessen weeding, preserve moisture and drying sunlight, and compost in place.  We found the mulch layer was also a deterrent to the Chinese Beetle who uses soil in its larval stage of development.  More observations are summarized in Chapter 4 of our Booklet. GrowingTableGrapes_Web

Objective Four:  Observe and record the effects of climate change on grape varieties chosen for the vineyards. 

 Climate change is beginning to impact agricultural systems in Hawaii and it's effects will continue to unfold.  We will prepare for this uncertain future by planting varieties that will survive in changing environments using sustainable growing methods. I have chosen grape varieties that have the potential to perform in different extreme environments  such as deserts, mountains, swamps and river valleys. I will observe and record the effects of weather on each variety including drier periods, wetter periods, effects of volcanic activity, and new and different pests and diseases connected to weather for each variety. End of Year One:  See attached document Rainfall Chart, and Log Book & Red Notebook Research pdf., Grape Log Photos pdf., and Red Folder Photos pdf. Rainfall Chart Kawanui Farm 2003Grape Survivors 2015-2022Red Folder Research PhotosLog Book PhotosLog Book & Red Folder Research notes

End of Year Two:  Rainfall in 2022 was recorded at 71 inches, down from almost 100 inches in the previous 2 years.  There were also more dry and sunny days.  Invasive species continue to increase on the Island of Hawaii,  but none of them so far has impacted grape production except for the Chinese Beetle.  Night time temperatures have been cooler than usual.  Sunny and somewhat drier weather (our usual before 2019 was 40" per year) has been good for grape growth, production, and sweetness.  Gerry continues to add notes to Log Book, and Red Folder Research Notes attached above.

Objective Five:  Taste and record the flavor profile of each grape variety.  Grapes produced in these systems must have excellent taste. 

Grapes will begin producing fruit in the third year, but to truly understand the taste prolife of each variety grown in different climatic years it will take a longer period of time.  However, most varieties that were planted will be producing fruit that will be tasted and used in a variety of value added ways from 2021-2023. It’s possible that some of these varieties will not produce flavorful grapes in this environment. It’s also possible that taste changes as climate changes. A year of extreme rains could produce a more “watered down” flavor and the next year with a drier climate could produce a grape with a more condensed flavor. A fine tasting grape is one that has a distinctive flavor, sweetness with an acid balance, an edible skin so it can be eaten whole, and if the variety has seeds they are softer and chewable.  I will create a chart that will reflect these qualities for each variety over the grant period and on into the future.  I will taste each variety out of hand, make them into juice, dry them for raisins, freeze them (sometimes creates a better taste), make jam and fruit leathers.   End of Year One:  We were not able to taste many varieties last summer due to rainfall, cloudy and cool conditions for most of 2021.  However, the weather pattern has changed and we had an early spring (end of January 2022) vineyards were pruned early as there was an early budding, and so we are anticipating good fruit set and harvest for end of Summer 2022.  End of Year Two:  Culinary observations for each variety are recorded in Chapter 8. Chapter 8

Research results and discussion:

GrowingTableGrapes_WebLog Book & Red Folder Research notesRainfall Chart Kawanui Farm 2003Chapter 8Red Folder Research PhotosLog Book PhotosGrape Survivors 2015-2022SURVEY FOR OUR GRAPE STAKEHOLDERS(2023-04-09)

Our Questions were:  Can we find table grape varieties that will grow well, be tough and hardy with good taste for Hawaii's growers?  

Can we create a Booklet summarizing our research that will help Hawaii's growers begin to trial and grow varieties of table grapes, using organic practices that will add to on-farm production and Hawaii's community food system?  

Our Answer is:  Yes.  In the short 2 years of additional trials, we looked at 58 varieties that were grown under challenging climatic situations, and found 12 varieties that thrived, and produced delicious fruit.  It will take another 3-5 years for all those varieties to come into full production, but because they were all trialed in extremely difficult climatic conditions, we are anticipating that more kinder climatic conditions (more sun, less clouds, less rainfall that has returned to Hawaii Island) they will be able to increase production.  We are already seeing that in the Spring of 2023.  We are watching our young grapes setting greater numbers of flowers and fruit earlier than we have seen in past years.  We are greatly encouraged

The Booklet summarizing our research is available here: GrowingTableGrapes_Web 

Mahalo for this opportunity to add a nutritious fruit to Hawaii's plate and food system using sustainable practices.  We will be continuing our educational outreach and research, adding knowledge to our farm website in the form of blogs, videos, research & reposts, resources, and photos.  

Participation Summary
2 Producers participating in research

Research Outcomes

Recommendations for sustainable agricultural production and future research:


Recommendations are included in our 56 page Booklet for Hawaii's Growers.  Additional recommendations are:  

Grapes thrive in organic systems in the subtropics.  Creating on-farm soil implements is essential to lessen the spread of invasive species, build soil health, and produce the highest quality nutritional product.  This type of healthy soil environment discourages pests and diseases.  

Future Research includes looking into other subtropical areas of the world who produce grapes, and seeing if UC Davis has any of those varieties. This year we began trialing 8 varieties from subtropical India, but so far only one of them is proving to be adaptable to Hawaii's climatic conditions.  Another research idea would be to trial the muscadine varieties from Southern Florida.  Our one Muscadine "Nesbitt" was a great producer.  It is not an eating grape but makes a fine juice and could possibly make a good wine.  We will be trying that in the Summer of 2023.  

188 New working collaborations

Education and Outreach

10 Consultations
32 Curricula, factsheets or educational tools
1 Journal articles
3 On-farm demonstrations
2 Published press articles, newsletters
4 Tours

Participation Summary:

20 Farmers participated
188 Ag professionals participated
Education and outreach methods and analyses:

All educational and outreach activities described in Educational Objectives have been achieved.  This includes 9 Quarterly Blogs, new Vineyard Photos, monthly Instagram postings,  new resources, research, and reports added to Grape Resource Page as they became available, 22 new on-farm instructional videos on our research and practices uploaded when created, and a 56 page Grape Booklet printed and distributed to interested Stakeholders.  This Booklet summarizes our research and gives recommendations for Hawaii's growers.  This Booklet was sent by mail in March to all interested Stakeholders and a downloadable pdf was posted on the farm website with a Shoutout sent to all Stakeholders.    I wrote an article for the University of Hawaii CTAHR newsletter Hanai'Ai summarizing  our research and education program that was published in March 2023, another summary article for the Hawaii Tropical Fruit Growers Association published in March 2023, and an article in West Hawaii Today.  All articles are downloaded in products.  

Educational products including Blogs, Photos, Resources, and Videos are available at

56 page Booklet titled "Growing Table Grapes in Subtropical Hawaii Using Organic Practices is available to view here: GrowingTableGrapes_Web

Education and outreach results:

When we began this project in April 2021, we had 50 contacts who had signed up to receive Shoutouts from our website  Today, 2 years later we have 302 members that includes 188 Grape Stakeholders who signed up to receive our educational materials.  

When we started we had less than 100 views on the site.  Today we have over 2,700.  According to our WIX analytics 94% of all viewers in this past year were new to the site.  When we posted our Grape Booklet we had a huge increase in visitor traffic mostly from Oahu which is very good.  It' aways difficult for outer Island projects to be seen on Oahu.  I think this was due to the College of Tropical Agriculture's Article in their Quarterly Newsletter in March 2023 (University of Hawaii), and the new Chair of the Hawaii Department of Agriculture sending our Shoutout announcing our Booklet's availability to the HDOA email list.  I also posted all my Grape Stakeholder Shoutouts on my personal Facebook page, and according to the WIX analytics, 51% of all traffic to the website came from Facebook.  I find this interesting and unexpected.  I continue to receive many emails every day from new growers interested in our work and the website created a place to discover all our grape resources for new growers.  Remember grapes are NOT grown in Hawaii, and no one thinks you can, so this research has been extremely important.  Other interesting analytics:  41% of website traffic over this past year came from social media which is 92% better than all websites in your category.  17% of all traffic was from returning visitors 75% better than websites in this category.  Average site session was 8 minutes and 51 seconds, better than 91% of sites in this category.  

Creating a Farm Website that included a page for Grape Blogs, Videos, Photos, Research Reports, Grape Resources and the Booklet, with regular communication with all our Stakeholders was very effective.  Since we plan on continuing this research and education project with our Stakeholders it will be interesting to see what develops in the future.  

But what will be the most enduring legacy from this project is our Grape Booklet "Growing Grapes in Subtropical Hawaii Using Organic Practices."GrowingTableGrapes_Web

The results of our online Survey that was created for our Stakeholders to share their experience with our 2 year education program is available here. Survey Results Stakeholders

17 Farmers intend/plan to change their practice(s)

Education and Outreach Outcomes

Recommendations for education and outreach:

Survey Results Stakeholders

Recommendations:  Stakeholders were interested in shorter blogs and videos focusing on one aspect of production at a time.  

Gerry conducted the research in the field and I was in charge of all educational activities.  I think it would be very difficult for a farmer to do both with inspired interest.  Farmers could find a partner with good writing and communication skills to partner with to achieve the educational objectives.  

Compiling the research and recommendations into a Booklet that was available for download on our website I think was a good idea.  Even though we only had 188 Stakeholders, this project has now reached 100s more people in the State of Hawaii.  Engaging the Chair of the State Department of Agriculture, the College of Tropical Agriculture of the University of Hawaii at Manoa, Farmers groups especially the Hawaii Tropical Fruit Growers Association, was also very important.  

Research to identify a new crop for a state takes time, it is a slow process, but a fascinating one when combined with an educational aspect that allows other growers to "come along" in the journey to discover best practices for a new crop, in this case the table grape for Hawaii.  

When we could not conduct on-farm workshops and had to learn to produce instructional videos instead it was a big challenge.  But we figured it out and worked together to create instructional videos that delve into all the different steps in bringing a grape vine from scion wood to the final table.  We are not able to create transcripts of these short videos, I was not able to figure that part out.  I hope that will be alright.  

Patience, Persistence, Observation, Research and reading, positive attitude all important.  


57 Producers reported gaining knowledge, attitude, skills and/or awareness as a result of the project
Non-producer stakeholders reported changes in knowledge, attitudes, skills and/or awareness as a result of project outreach
47 General public
11 Ag Service Providers
Key changes:
  • Not letting me insert Stakeholder Survey Results into this area.

Information Products

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.