Final Report for LNE11-306
Project Information
The goal of this project was to increase returns to garlic growers about the benefits of quality garlic seed through education. Over 300 garlic growers received information about workshops on Identification and Management of Garlic Pests and Diseases and over 650 garlic growers from Maine, New Hampshire, and New York attended 24 presentations on garlic. Five publications, a webinar/video and two YouTube videos were developed with over 49,000 page views during the time frame of this grant. Additionally, a website http://umaine.edu/agriculture/programs/garlic/) was developed with over 800 views during the time frame of this grant. As a result of this project, 80% of the garlic growers can now recognize major garlic diseases; 92% realize the importance of major garlic diseases in garlic production; and 71% of garlic growers changed their management strategy to look to plant nematode-free or disease-tested garlic seed stock.
Introduction:
There are over 70 commercial garlic growers in Maine representing all 16 counties. There is no seed program present for disease testing and many garlic growers produce garlic bulbs for table use as well as garlic cloves for seed. Importation of seed stock and exchange of live plant material has contributed to new pathogens being imported into and distributed within Maine. Two previously unreported pathogens have been imported on garlic seed stock. Losses on some affected farms exceeded 40 percent.
Garlic was put into tissue culture to produce garlic seed stock free from pathogens. While there was success producing tissue-culture generated garlic bulbs, scaling up to a commercial quantity proved to be difficult. Efforts are continuing beyond the grant to address laboratory hurdles in producing tissue-culture generated garlic bulbs. The seedlings had a difficult transition from the greenhouse to the field. Additionally, the seedlings needed longer to mature than the season allowed. The seedlings also did not produce bulbs with typical multiple cloves, but rather a single clove or a “rounds,” indicative of a stressful situation. Efforts are continuing beyond the grant to address this situation as well.
Shortly after this project was started, a garlic bloat nematode epidemic appeared in New York and New England. As a result of the epidemic, the main garlic seed concern growers had was obtaining planting stock free from the garlic bloat nematode. Developing disease-free seed through tissue culture was the target of the project. Identifying garlic diseases as well as sources of disease-free garlic planting stock for growers as well as resellers became a priority.
One hundred garlic farmers will recognize major garlic diseases and realize their importance in garlic production. Twenty-five garlic farmers will adopt the new technique of planting pathogen-free garlic bulbs to eliminate introduced pathogens. These twenty-five growers will increase their returns by $4000 per acre.
Cooperators
Research
Laboratory procedures:
There are great differences among garlic types regarding how well they adapt to tissue culture. Generally, the porcelains types tend to do better than the rocambole types. There is also a wide difference between isolated callus within a garlic variety as well as isolated callus within a single clove slice. Learning the nuances of the different garlic cultivars is critical. Recognizing when callus tissue has exhausted the media and should be transferred onto fresh media is also critical.
Develop garlic callus cultures from a bulb:
Pull the cloves from the bulb and peel the protective wrapper off a clove and soak the clove in a 10% bleach solution for 5 minutes. With a sterilized scalpel, cut off and discard about 1 mm off the end of the basal plate as this is often a source of contamination. Using a sterilized scalpel, cut off slices 2 to 3 mm thick parallel to the basal end of the clove. Place these slices onto a plate of callus medium. In about 8 weeks in the dark at 20°C, callus growth appears at the edge of the slices. Generally, callus tissue can be expected to develop in 1 in 5 slices with fresh bulbs, with much less in older bulbs. Contamination is greatest closest to the basal plate and increases with age of bulbs. This is the stage with the greatest loss to contamination.
Callus medium (1 liter):
3.2 g Gamborg’s B-5 Basal Medium with Minimal Organics
(Sigma G6593-10L)
30 g Sucrose (Sigma S5801-5KG)
2.5 g Phtyogel (Sigma P-8169-250g)
1 ml 6-(y,y-Dimethylallylamino)purine solution (2iP)
(Sigma D7674-1G)
{6-(y,y-Dimethylallylamino)purine solution (2iP) (50 ml):
Dissolve 0.05 g in 5 ml NaOH; bring up to 50 ml}
1 ml 2,4-Diclorophenoxyacetic acid solution (2,4-D)
(Sigma D7299-100G)
{2,4-Diclorophenoxyacetic acid solution (2,4-D) (50 ml):
Dissolve 0.05 g in 5 ml NaOH; bring up to 50 ml}
Adjust to pH 5.7 drop by drop with HCl
Multiply garlic callus tissue cultures from newly developed cultures:
When the callus growth extends out about 3 to 4 mm from the clove slice, remove the callus and streak them across a new plate filled with callus medium, leaving bits of callus cells distributed across the plate. In about 8 weeks in the dark at 20°C, these callus bits increase in size to about 1 cm in diameter. Generally, increase in callus tissue can be expected to be 1 to 5 times starting amount. Contamination loss does occur with this stage, but less so than the previous step.
Produce stems from garlic callus tissue cultures:
When the callus bits are about 1 cm in size, remove them and streak them across a plate filled with stem medium, leaving bits of callus cells distributed across the plate. These plates require a 16-hour light, 8-hour dark cycle at 20°C. After about 8 weeks, sprouts begin to form from the callus tissue. Generally, stems can be expected to develop on about 60% of the transferred callus tissue. Contamination loss does occur with this stage, but less so than the previous step.
Stem medium (1 liter):
3.2 g Gamborg’s B-5 Basal Medium with Minimal Organics
(Sigma G6593-10L)
30 g Sucrose (Sigma S5801-5KG)
2.5 g Phtyogel (Sigma P-8169-250g)
3 ml 6-Benzylaminopurine solution (BAP)
(Sigma B3408-1G)
{6-Benzylaminopurine solution (BAP) (50 ml):
Dissolve 0.05 g in 5 ml NaOH; bring up to 50 ml}
Adjust to pH 5.7 drop by drop with HCl
Produce bulbs from garlic callus tissue cultures with stems:
Transfer intact callus tissue with developed sprouts to bulb medium. These plates require a 16-hour light, 8-hour dark cycle at 20°C. After about 4 weeks, bulbs will be initiated by the sprouted callus bits. Generally, bulbs can be expected to develop on about 60% of the transferred callus tissue with stems. Contamination loss does occur with this stage, but less so than the previous step. These bulbs are very small. After 8 weeks, the bulbs can be transferred to new plates filled with bulb medium which can increase their size.
Bulb medium (1 liter):
4.4 g Murashige and Skoog Basal Medium (Sigma M6899-1l)
(MS)
120 g Sucrose (Sigma S5801-5KG)
Adjust to pH 5.8 drop by drop with HCl
Greenhouse procedures:
Produce plants from garlic callus tissue bulbs:
Plant the tiny bulbs in a greenhouse in standard potting medium. Place cultures under standard grow lights providing 16-hour light, 8-hour dark period. Plants should be held at ambient temperature (20°C) and are slow to grow.
Field procedures:
Produce field-grown bulbs from greenhouse-grown garlic plants:
Transplant the greenhouse plants into the field when the danger of frost is past.
YEAR 1
September 2011
100 Maine garlic growers will receive material on an intense workshop on Identification and Management of Garlic Pests and Diseases. Of these 100 growers, 25 will attend an intense workshop on Identification and Management of Garlic Pests and Diseases. Ten of these growers will change their management strategies and commit to measuring the impacts of their management change.
Completed with presentation January 10, 2012 and a presentation on January 11, 2012 with over 140 in attendance.
October 2011
1000 pathogen-free garlic bulbs will be planted by three key garlic growers. One grower is from Massachusetts and two are from Maine. These growers will monitor the pathogen-free garlic planting and compare it to their traditional planting.
Owing to a funding delay, the tissue culture portion of the project was not able to be initiated in time for the October planting season.
November 2011
100 Maine garlic growers will receive material on an intense workshop on Growing Healthy Garlic. Of these 100 growers, 25 will attend an intense workshop on Growing Healthy Garlic. Ten of these growers will change their management strategies and commit to measuring the impacts of their management change.
Completed with presentations on March 26, 2012, March 27, 2012 and March 28, 2012 with over 106 in attendance.
August 2012
Garlic crop is harvested from the planting of 1000 pathogen-free garlic bulbs. These growers will commit to measuring the yield and dollar impact of the pathogen-free garlic planting compared to their traditional planting.
Owing to a funding delay, the tissue culture portion of the project was not able to be initiated in time for the October planting season therefore there was no harvest.
YEAR 2
September 2012
An additional 100 Maine and Massachusetts garlic growers will receive material on an intense workshop on Identification and Management of Garlic Pests and Diseases. Of these 100 growers, 25 will attend an intense workshop on Identification and Management of Garlic Pests and Diseases. Ten of these growers will change their management strategies and commit to measuring the impacts of their management change.
Completed with presentations on September 21, 2012 and October 30, 2012 to more than 110 in attendance.
October 2012
2000 pathogen-free garlic bulbs are used for planting by three key garlic growers. One grower is from Massachusetts and two are from Maine. These growers will monitor the pathogen-free garlic planting and compare it to their traditional planting.
While there was success producing tissue-culture generated garlic bulbs, scaling up to a commercial quantity proved to be difficult. About 200 tissue-culture generated garlic bulbs were produced. Concern regarding the small size and overwintering ability of the bulbs guided the decision to plant them in one location in Maine. The University of Maine Experimental farm was chosen as the location in order to be able to closely and regularly observe them.
November 2012
An additional 100 Maine and Massachusetts garlic growers will receive material on an intense workshop on Growing Healthy Garlic. Of these 100 growers, 25 will attend an intense workshop on Growing Healthy Garlic. Ten of these growers will change their management strategies and commit to measuring the impacts of their management change.
Completed with two presentations on December 13, 2012 to more than 30 in attendance.
January 2013
An additional 100 Maine and Massachusetts garlic growers will receive material on garlic production from pathogen-free bulbs, 25 will attend the workshop where preliminary findings are presented.
Completed with a presentation on February 2, 2013 to more than 40 in attendance.
July 2013
An additional 100 Maine garlic growers will receive material on two twilight meetings on identification and management of garlic pests and diseases. Of these 100 growers, 25 will attend a twilight meetings on identification and management of garlic pests and diseases. Ten of these growers will change their management strategies and commit to measuring the impacts of their management change.
Communication with selected garlic growers led us to cancel this idea. While the idea was sound, the timing was unworkable. The unanimous theme was that during summer growing and marketing season, no growers could commit to attend. As an alternative, the two principal investigators made themselves available for numerous field visits to garlic growers. Few, if any field calls for garlic problems had been done in Maine historically, so this was well received.
August 2013
Garlic crop is harvested from the planting of 2000 pathogen-free garlic bulbs. These growers will commit to measuring the yield and dollar impact of the pathogen-free garlic planting compared to their traditional planting.
Concern regarding the small size and overwintering ability of the bulbs was well founded. Just over 5 percent of the 200 planted bulbs survived. Plant growth was spindly and only 1 bulb differentiated into cloves. Most were “rounds” indicative of stressful growing conditions.
YEAR 3
September 2013
An additional 100 Maine and Massachusetts garlic growers will receive material on an intense workshop on Identification and Management of Garlic Pests and Diseases. Of these 100 growers, 25 will attend an intense workshop on Identification and Management of Garlic Pests and Diseases. Ten of these growers will change their management strategies and commit to measuring the impacts of their management change.
Completed with presentations on October 1, 2013, October 17, 2013; two presentations on October 24, 2013; one presentation in November 10, 2013; and two presentations on December 4, 2013 to more than 195 in attendance.
October 2013
2000 pathogen-free garlic bulbs are used for planting by three key garlic growers. One grower is from Massachusetts and two are from Maine. These growers will monitor the pathogen-free garlic planting and compare it to their traditional planting.
Laboratory issues continued and scaling up to a commercial quantity proved to be difficult again. About 1000 tissue-culture generated garlic bulbs were produced. While this is more than the previous year, successfully growing the crop to bulbs had not been done so the again, the decision was made to plant them at the University of Maine Experimental farm. The decision was made to increase tissue culture generated bulbs for spring planting in the greenhouse to increase the likelihood of survival.
November 2013
Assessment, verification, and data collection from key growers and from workshop growers on dollar sales increases and pounds of yield increase as a result of using pathogen-free garlic bulbs.
January 2014
An additional 100 Maine and Massachusetts garlic growers will receive material on garlic production from pathogen-free bulbs, 25 will attend the workshop where preliminary findings are presented.
Completed with a presentation on October 2, 2014.
July 2014
An additional 100 Maine garlic growers will receive material on two twilight meetings on identification and management of garlic pests and diseases. Of these 100 growers, 25 will attend a twilight meetings on identification and management of garlic pests and diseases. Ten of these growers will change their management strategies and commit to measuring the impacts of their management change.
This was again cancelled as communication with selected garlic growers resulted in the same unanimous theme was that during the summer growing and marketing season they were too busy. Again, the two principal investigators made themselves available for numerous field visits to garlic growers. The mountain of requests for visits indicated that this approach was well received.
August 2014
Garlic crop is harvested from the planting of 1000 pathogen-free garlic bulbs. These growers will commit to measuring the yield and dollar impact of the pathogen-free garlic planting compared to their traditional planting.
Field issues continued to hinder the project. Less than 5% of the tissue culture generated bulbs survived and not differentiated into a bulb with cloves. Limited survival of the garlic transplants from the green house occurred with not of the plant ready for harvest when harvest time arrived.
WRAP UP
September 2014
Pathogen-free bulbs are available to garlic growers.
This was not accomplished.
October 2014
Assessment, verification, and data collection from key growers and from workshop growers on dollar sales increases and pounds of yield increase as a result of using pathogen-free garlic bulbs.
This was not accomplished.
November 2014
Assessment, verification, and data collection from key growers and from workshop growers on dollar sales increases and pounds of yield increase as a result of using pathogen-free garlic bulbs.
This was not accomplished.
January 2015
Completed information from the project findings will be presented to interested New England garlic growers. Information from the project findings will be distributed throughout the region through fact sheets and conference presentations including the Maine Agricultural Trades Show and the New England Vegetable and Berry Growers Conference as the opportunity arises.
Completed (but still ongoing) with one presentation on January 20, 2015.
Education
As part of the project, 24 presentations on garlic were given to over 650 garlic growers from Maine, New Hampshire, and New York. Topics included garlic production, garlic diseases, and growing healthy garlic. In addition, five publications, a webinar/video and two YouTube videos were developed with over 49,000 page views during the time frame of this grant. Additionally, a website (http://umaine.edu/agriculture/programs/garlic/) was developed with over 840 views during the time frame of this grant. Owing to the UMaine webpage setup, views of the webinar/videos could not be tracked. These outreach efforts are detailed below.
Presentations:
Johnson, S. B. 2015. Garlic and Root Crops Storage: What Works and What Doesn’t. Presented at the Empire State Producers Expo on January 20, 2015 in Syracuse, NY.
Fuller, D. 2014. Growing Healthy Garlic. Presented in Livermore Falls, ME on October 2, 2014.
Johnson, S. B. 2013. Growing Healthy Garlic. Presented at the Cape Elizabeth Garden Club Meeting in Cape Elizabeth, ME on October 24, 2013.
Johnson, S. B. 2013. Bloat Nematode in Maine Garlic -- A New Pathogen in Maine. Presented at the 73rd Meeting of the Northeast Division of the American Phytopathology Meeting in Southbury, CT on October 24, 2013.
Fuller, D. 2013. Growing Healthy Garlic and Dealing with Old and New Diseases. Presented in Lowell, ME on October 17, 2013.
Fuller, D. 2013. Growing Healthy Garlic and Dealing with Old and New Diseases. Presented in Rangeley, ME on October 1, 2013.
Fuller, D. 2013. Growing Healthy Garlic and Dealing with Old and New Diseases. Presented at the Farmington Seed Savers 3rd Annual Winter Conference on February 2, 2013 in Farmington, ME.
Johnson, S. B. 2013. Bloat Nematode in Maine Garlic – A New Pathogen in Maine. Presented at the 73rd Meeting of the Northeast Division of the American Phytopathology Meeting in Southbury, CT on October 24, 2013.
Johnson, S. B. 2013. Growing Healthy Garlic: Disease and Storage Issues. Presented in Deer Isle, ME on December 4, 2013.
Fuller, D. 2013. Growing Healthy Garlic. Presented in Deer Isle, ME on December 4, 2013.
Fuller, D. 2013. Maine Garlic Research Update. Presented at the Maine Chapter of the National Association of Agricultural Agents in Orono, ME on November 25, 2013
Johnson, S. B. 2013. Growing Healthy Garlic. Presented at the Cape Elizabeth Garden Club Meeting in Cape Elizabeth, ME on October 24, 2013.
Johnson, S. B. 2013. Bloat Nematode in Maine Garlic – A New Pathogen in Maine. Presented at the 73rd Meeting of the Northeast Division of the American Phytopathology Meeting in Southbury, CT on October 24, 2013.
Fuller, D. 2013. Growing Healthy Garlic and Dealing with Old and New Diseases. Presented in Lowell, ME on October 17, 2013.
Fuller, D. 2013. Growing Healthy Garlic and Dealing with Old and New Diseases. Presented in Rangeley, ME on October 1, 2013.
Fuller, D.F. 2012. Testing of Seed Garlic for Common Ground Fair Seed Garlic Sellers. Presented at the Farmer’s Market Steering Committee Meeting on December 13, 2012 in Unity, ME.
Johnson, S. B. 2012. Pest Biology and Identification. Presented at the Farmer’s Market Steering Committee Meeting on December 13, 2012 in Unity, ME.
Johnson, S. B. 2012. Garlic: An update on Production and Dealing with Old and New Pests. Presented at the Maine Agricultural Trades Show on January 10, 2012 in Augusta, ME.
Johnson, S. B. 2012. Disease issues for Garlic and other Bulb Crops. Presented at the Maine Agricultural Trades Show on January 11, 2012 in Augusta, ME.
Johnson, S. B. 2012. Disease Issues for Garlic. Presented at the First Annual Capital District Garlic School on March 26, 2012 in Saratoga Springs, NY.
Johnson, S. B. 2012. Disease Issues for Garlic. Presented at the First Annual Geneva Garlic School on March 27, 2012 in Geneva, NY.
Johnson, S. B. 2012. Disease Issues for Garlic. Presented at the First Annual Ithaca Garlic School on March 28, 2012 in Ithaca, NY.
Fuller, D.F. 2012. Garlic Production Update and Dealing with Old and New Pests. Presented at the Common Ground Country Fair, September 21, 2012 in Unity, ME.
Johnson, S. B. 2012. Garlic Diseases. Presented at the North Country Fruit and Vegetable Seminar and Trade Show on October 30, 2012 in Whitefield, NH.
Publications:
Johnson, S. B. and Fuller, D. 2015. Garlic White Rot. University of Maine Cooperative Extension Bulletin, in manuscript.
Johnson, S. B. and Fuller, D. 2015. Garlic Fertilization in Maine. University of Maine Cooperative Extension Bulletin, in manuscript.
Fuller, D. and Johnson, S. B. 2015. Drying and Curing Garlic. University of Maine Cooperative Extension Bulletin, in manuscript.
Johnson, S. B. and Fuller, D. 2014. Bloat Nematode in Maine Garlic – A New Pathogen in Maine. Phytopathology 104:3.
Fuller, D. F. and Johnson, S. B. 2013. The Maine Garlic Project: A Participatory Research and Education Program. Journal of Extension [On-line], 50(5) Article 5TOT8. Available at: http://www.joe.org/joe/2013august/tt6.php
Johnson, S. B. and Fuller, D. 2013. Blue Mold of Garlic. University of Maine Cooperative Extension Bulletin, 1206, 2pp. Available at: http://umaine.edu/publications/1206e/
Fuller, D and Johnson, S. B. 2013. Growing Hardneck Garlic in Your Maine Garden. University of Maine Cooperative Extension Bulletin, 2063, 3pp. Available at: http://umaine.edu/publications/2063e/
Johnson, S. B. and Fuller, D. 2013. Botrytis Neck Rot in Maine Garlic, 1207, 2pp. Available at: http://extension.umaine.edu/publications/1207e/
Webinars/Videos:
Fuller, D. and Johnson, S. B. 2015. Harvesting and Drying Garlic, in draft
Fuller, D. and Johnson, S. B. 2015. Storing Garlic, in draft
Johnson, S. B. and Fuller, D. 2013.Growing Healthy Garlic: Curing and Disease Issues. (http://www.umext.maine.edu/potatoprogram/garlic/Growing%20Healthy%20Garlic%20Curing%20and%20Disease%20Issues.wmv)
Web Page:
http://umaine.edu/agriculture/programs/garlic/
Additional Project Outcomes
Impacts of Results/Outcomes
Performance Target
One hundred garlic farmers will recognize major garlic diseases and realize their importance in garlic production and 30 farmers will adopt the new technique of planting pathogen-free garlic bulbs and their crop losses from introduced pathogens will be eliminated as will the spreading of these pathogens through their seed sales.
A garlic grower mailing list with 263 names on it was surveyed with a return rate of 25 percent, which generally is what is expected. Extrapolating the reported data to the population yields very encouraging results. 80% of the garlic growers can now recognize major garlic diseases; 92% realize the importance of major garlic diseases in garlic production; and 71% of garlic growers changed their management strategy to look to plant nematode-free or disease-tested garlic seed stock. This is well supported by garlic growers looking for clean planting stock. During the period of study there were 370 garlic bulb and soil samples submitted for pathogen testing as a result of the grant-related outreach efforts. While the samples were being tested for garlic bloat nematode, destructive diseases caused by Sclerotium cepivorum, Botrytis porri, and Fusarium spp. were identified and information delivered to the grower on how to deal with the pathogen found on their sample. Many of these samples were a direct result of the educational outreach efforts. Numerous workshops on growing healthy garlic and recognizing diseases and what to do about them were well received. Pre- and post-workshop surveys revealed a 100% increase in garlic grower’s ability to identify diseases. Crop rotation, disease identification, and were topics reported by attendees as practices that they will implement. Subsequent access of over 49,000 views of on-line educational efforts show a further interest in better understanding garlic diseases.
No farmers planted tissue-culture generated garlic bulbs owing to laboratory hurdles. Without significant breakthroughs in the laboratory, there is not a great deal of hope for tissue culture-generated garlic bulbs to be available on a commercial scale. Greenhouse-grown seedlings may be an alternative, but there are still questions as to the commercial viability of the process. Efforts are continuing to address these issues. Growers did however, plant garlic bulbs pathogen-free as currently available. This was accomplished through educational outreach activities and extensive laboratory testing. The 370 samples submitted for pathogen testing went a long way toward accomplishing disease-free garlic seed as some seed stocks were culled out as result of testing positive for some pathogens. As a result of the educational outreach efforts, growers were demanding certifications of health through laboratory testing of the seed stock they wanted to buy and plant and was made mandatory by major garlic seed resellers. We think the objective of one hundred garlic farmers recognizing major garlic diseases and realizing their importance in garlic production was soundly met. We also think the objective of 30 farmers adopting the new technique of planting pathogen-free garlic bulbs was soundly met.
Economic Analysis
Detailed economic data were not collected as the delivery of tissue culture- generated garlic bulbs delivered to growers was not realized. Data on value of, planting garlic bulbs pathogen-free as currently available was collected and appears elsewhere in this report.
Farmer Adoption
The two largest garlic seed resellers are now requiring their growers to have their garlic tested for diseases before they are willing to market it. Independent garlic seed buyers were asking sellers for proof that their garlic had been tested before buying. Many growers reported that they could not sell their garlic for seed had they not attended workshops, learned about pathogen testing, and had their crop tested.
A sampling of feedback quotes from farmers received:
“I’ll put this information to use immediately”
“A number of my garlic contemporaries in other states are jealous of the service and expertise that I have access to via Fuller and Johnson.”
“After attending your talk, I sold $7,000 worth of garlic seed in 3 days as a result of having tested my garlic seed tested for diseases. Thanks Dave for the great presentation.”
“That same attention to the best science regarding propagation, diseases and pests, and “seed” quality can truly build a Garlic “seed” grower base that the rest of the country desperately needs.”
“The research Fuller and Johnson conduct is key to education, product quality, and market development.”
“Many buyers from other states recognize disease and pest analysis by Johnson as a gold standard of product quality assurance. A number of Farm and Garden mail-order businesses currently rely on the testing, research, and council of Fuller and Johnson to guide and grow garlic sales.”
Areas needing additional study
Any progress overcoming laboratory hurdles in tissue culture prosecution may make the practice viable for the future. Further investigation on the value of disease-free garlic seed to growers should continue.
Information Products
- Agricultural Programs Garlic
- The Maine Garlic Project
- Garlic in the Home Garden Removing Scapes
- Growing Hardneck Garlic in Your Maine Garden
- Bloat Nematode in Maine Garlic
- Blue Mold of Garlic
- Botrytis Neck Rot in Maine Garlic
- Growing Healthy Garlic Curing and Disease Issues Transcript
- How Do I Grow Garlic in Maine