Progress report for FNE22-003
This project will contribute to an understanding of whether figs are a viable fruiting crop for retail and wholesale markets for distribution in the NE. The main objectives of the project are:
(1) Establish a fig orchard with low-cordon espalier using the Japanese Stepover method and (2) replicate the results of previous efforts in this area with improvements to determine if the above method is viable and scalable for fruit production.
(1) Utilize high tunnels to extend the seasons on each end--both spring and fall and (2) use low tunnels with light mulching to further create a microclimate for cordons to survive the winter and consistently produce a fig crop.
My hope is to get one step closer to inaugurating a wave of northeastern commercial fig orchards, bringing this ancient and elusive fruit to our climate so that it can be shared and treasured regardless of socioeconomic status. If successful with figs, other Mediterranean fruits may also be grown similarly, on a commercial scale. If we can redefine local as meaning within 50 miles--not 500 miles--I believe we can make the lives of both farmers and consumers more gratifying.
Figs were one of the very first cultivated fruit trees (1). The tree and its fruit (or flower, rather) have inspired stories and cultures in both ancient and modern times. Although figs have been successfully cultivated in the Northeast for many years in backyards both in-ground and pots, no commercial fig growing operations exist north of the Mason-Dixon line. In fact, California produces 98% of the country's fresh and processed fig fruit (2). How do we build upon the success of backyard fig enthusiasts, who are indeed harvesting fig fruit consistently from pots and in-ground trees throughout the Northeast, and scale that into a commercial operation in which figs are produced, marketed, and sold locally?
I’d like to apply new growing and overwintering techniques to Mediterranean fruit crops, starting with the fig, using high tunnels. If we can learn to produce high-value crops like figs, which are typically grown on the West Coast and shipped across the continent, this will help reduce our carbon footprint. This will also provide more people an opportunity to taste a locally produced, fresh fig versus one that is necessarily harvested early for extended transport. This is at odds with the fig's ephemeral quality; when picked and eaten at its peak of ripeness, it is beloved, and has inspired thousands of backyard growers.
Whereas some have reported success in growing figs and other unique crops like citrus throughout the tri-state area, the larger commercial market is unexplored. The barriers to entry in growing Mediterranean crops are high, and the accessibility of information to enter the market is scarce. If we can develop a more sustainable way to overwinter fig trees in zones 6 and 7, we can bring local fig fruit to retail and wholesale markets in the tri-state area, while minimizing fossil fuel expenditures. This in turn will produce more local jobs and grow the market share directly for figs and other Mediterranean-originated fruit grown and sold in the Northeast.
Historically, the heating high tunnels used for growing figs has been inefficient. The entire tunnel is typically heated, using natural gas, propane, or fuel oil. This method wastes both energy and space. Fig trees are unique, in that the fruit forms on new growth, not old growth. I propose using the Japanese Stepover Espalier technique (3), Using this method, permanent cordons are established slightly above or at ground level (at ground level, they can be mulched for an extra layer of protection). Once the cordons are established, fruiting branches can be formed every 14 inches along the horizontal growth. These vertical branches are then pruned back every year and new buds emerge the following year, forming new vertical branches on which fruit will form.
To overwinter these cordons, I would use Eliot Coleman’s system (4) of floating row covers over the cordons inside the high tunnel. Coleman has used this method for years to grow cold-hardy crops without heat in Maine. According to Coleman, "Double coverage moves the covered area about three USDA zones to the 'south' "(5). During extremely cold nights or weeks, greenhouse plastic could also be added directly on top of this floating row cover. This method allows the soil to store the heat. Coleman commented, “When the outdoor temperature drops to –15˚F (–26˚C), the temperature under the inner layer of the cold house drops only to 15˚F to 18°F above zero (–10˚C to –8°C) on average (5).” Cold-hardy fig trees will suffer no die back until the temperatures are consistently lower than 15˚F. An alternative source of income could be produced while the trees are dormant by planting cold-hardy crops under these row covers.
- - Technical Advisor (Educator)
The first step in the process of establishing a Japanese Stepover Espalier is to plant fig trees in the high tunnel. My fig cuttings are started in cells during the winter; therefore, the trees will be about 1 foot tall when transplanted from their cells. At the time of planting, the apical bud will be pinched to induce branching. From this branching, two leaders will be chosen as the cordons. A piece of wire will run 1 inch from the ground over the length of the row, and tomato clips will attach the cordon to the wire.
The selected branches will be allowed to grow 2 1/2 feet vertically. Once this growth is established, the lower 6 inches will be clipped to the guide wire. This will allow the apical bud to continue growing vertically (which is more vigorous than horizontal growth), while slowly training the cordon along the wire. The bottom will need to be trained horizontally biweekly or whenever the horizontal growth is above 2 1/2 feet, encouraging cordon formation horizontally. Leaves will be trimmed from the cordon as it is attached to the wire. During this period, the trees will be fed a high nitrogen fertilizer via micro sprinklers.
The primary goal in 2022 is to establish healthy cordons and to gain optimal thickness. Thicker, more lignified fig wood survives lower temperatures better than thinner, non-lignified wood (1). To accomplish this, all suckers and fruit will be pruned in the first year until the desired length of the cordon is reached. Trees will be spaced 7 feet apart in each row, with 6 feet between rows, allowing for 52 trees in two 30 x 96 high tunnels, or a total of 104 trees.
In late December 2022, when the trees have gone dormant, wood chip mulch will be spread 6 inches wide and 3 inches
deep over the cordons. Eliot Coleman-style vole traps (non-baited mouse traps set inside of wooden boxes with small entrance holes) will be placed inside and outside the high tunnel (2). Voles can do serious damage to a fruit orchard by girdling the bark and eating through the base of the plant. Vole traps will be checked and reset daily through the winter months. In addition to these traps, free-roaming predators (e.g., cats) will be employed to further protect the high tunnels and plants.
At this time, a wireless thermometer and humidity gauge will be placed directly in the center of the high tunnel, at 6 feet high. The thermometer will be connected via WiFi to a smart phone enabling easy monitoring of the temperature and humidity hourly. Once nightly high-tunnel temperatures begin to dip into the mid-20s for more than an hour or two a night (estimated, mid to late December), the low tunnels will be deployed, with floating row covers over the cordons. A second sensor will be placed on top of the mulch inside of the high tunnel, and a third sensor will be placed at the top of the arch inside of the low tunnel. Both high and low temperature readings from these three resources will be recorded daily.
Before planting the figs in the high tunnels, a support system greenhouse will be hung from the rafters of the high tunnel. S hooks will be attached to the support system, and Tomahooks will be used to establish the vertical fruiting branches from the cordon. Starting in the later summer of 2022 or spring of 2023, buds will be allowed to form on the cordon every 14 inches. All other buds will be removed at first sight. These buds will form the fruiting branches. The vertical branches will need to be pruned of suckers and trained with tomato clips weekly. Once fruit begins to form and reaches about 1 inch in diameter, the leaves will be pruned from the bottom of the plant moving up (like pruning low vegetative growth on greenhouse tomatoes to improve airflow). As figs are harvested, from the bottom of the verticals up, leaves will continue to be pruned to increase air flow. Starting in March of 2023, the trees will be fed a balanced fertilizer through the micro sprinklers to encourage vertical growth and fruiting.
About 90 days is required for figs to progress from embryo formation to ripening. The emergence of fig embryos will be recorded for each variety. Since embryos can be rather small at first, we will define an embryo as the size of a small pea. The first embryo formation and ripening date of each individual tree will be recorded for each fruit. The amount of fruit harvested from each variety will be recorded along with the date of the last fig ripening. These results will be compared with those of an unprotected test plot of each variety planted in an adjacent open field in 2022, using landscape fabric for ground cover. If any figs remain on a tree at the end of the season, the amount of unripe fruit will be recorded. The end bud on each vertical branch will be pinched off around July 15th, because of the 90-day gestation and optimal growth in higher temperatures (any figs forming after this date are unlikely to ripen). Once the trees have gone dormant in the greenhouse, the vertical branches will be pruned back to 2 nodes. The cordon will be mulched in December and covered with floating row cover.
The same process should be repeated in 2024. As the cordons of the Japanese Stepover Espalier mature, this would provide an opportunity to compare fig production from year 1 (2023) to year 2 (2024). It is also important to allow two years of growth and data recording to account for varying winter temperatures: If the winter of 2022 is mild, we may not have a cold enough winter to determine if growing the trees in high tunnels with mulching and the low tunnel system has any real effect on production and overwinter versus unprotected growth in the ground.
The temperature monitoring system was set up in early December. Five monitoring stations are placed in the following areas:
- Monitor 1 has been placed on the ground outside of the High Tunnel
- Monitor 2 is connected to the top of the wire hoop inside of the low tunnel.
- Monitor 3 has been placed on the ground inside of the low tunnel.
- Monitor 4 has been placed on the ground, outside of the low tunnel.
- Monitor 5 has been placed on the ground outside of the low tunnel, next to the northern wall of the high tunnel.
The full results of the temperature monitoring are premature, but so far, the floating row cover has produced significant increases in air and soil temperatures inside of the low tunnel during the month of December. The low this December on the outside of the high tunnel has been 4 degrees Fahrenheit recorded on the evening of December 24th, while the temperature on the soil inside of the low tunnel that evening was 24 degrees Fahrenheit. The temperature on the ground next to the low tunnel that same evening was 17 degrees. When the temperature outside rose the following day to 29 degrees the temperature on the ground inside the low tunnel went to 62 degrees.
The highest temperature recorded on top of the soil inside of the low tunnel was 87 degrees on December 30th. The temperature on the outside of the high tunnel that day was 42 degrees. For comparison, the highest temperature recorded at the top of the low tunnel was 93 degrees on December 30th when the temperature outside was 42 degrees. That is a temperature difference of 51 degrees on a sunny day. So far, none of the fig's cordons have been damaged by the low temperatures inside of the high tunnel. We will continue to monitor and report on these temperature changes and averages in our next report.
It will be interesting to see how the raised temperatures inside of the low tunnels contribute to the breaking of dormancy in the figs. Typical bud break inside of a greenhouse/high tunnel for figs in zone 6b is the beginning of April. Our hypothesis is that the low tunnel set up will help induce bud break by mid-March. A two- week earlier start could be the difference between ripening a fig crop and none at all.
December Temperature Readings Monitor 1 Outisde of High Tunnel Green Line= Temperature
December Temperature Readings Monitor 2- Attached to top wire of Floating Row Cover
December Temperature Readings Monitor 3- On Ground inside of Floting Row Cover
December Temperature Readings Monitor 4- On Ground outside of Low Tunnel
Education & Outreach Activities and Participation Summary
This year the youtube channel will be started. The channel will be titled Coastal Fig Company which is our nursery name. Please follow along for updates to our progress.
One possible outcome of this project is seeing an increase in numbers of individuals and farmers growing figs inside of high tunnels. I also believe that a probable outcome will be intercropping greens and other cold hardy vegetables between the rows of figs during the winter months. This is yet to be trialed determined as our project progresses.
The one challenge I had from the project this year was some stunted growth on the figs planted in May. Looking back, I would have planted trees in one-gallon pots as opposed to planting them directly from tray cells into the soil. Planting figs with a more established root system would have sped up the overall growth process in the first year. Perhaps, planting larger plants would have meant achieving some vertical to grow the first season.