Cross-posted on OurFigs so forgive the repetition if you already saw that thread.
Timeline
11/10- Heavy row cover placed on both sites (1.5oz).
12/9- Poly placed on both sites (3.5mil overwintering Ginegar)
Temperature Highlights (lowlights?)
**11/12: 20.7F in Low Tunnel, 13.8F outside (rc only).
11/16: 15.6F in LT, 13.8F outside (rc only).
1/20: 9.9F in LT, -2F outside.
**2/7: 25F in LT, -0.9F outside.
2/14: 14.5F in LT, -5.4F outside.
On the dates marked with ** there was significant snowfall and I used a snowblower to make a figloo (see pictures from last year). As you can see from the dates/temps immediately following the ** dates, the benefit of snow cover doesn’t stick around forever. The 9.9F on 1/20 was the lowest temperature the figs experienced.
Successes and Failures
By using 3/4" anchor legs, I increased the height of the tunnel a foot. This presented several problems. The first was that the 10 foot wide row cover from last year just barely covered the hoop space, and in reality it didn’t cover the space because of the wind pulling it up or it getting shifted when the poly was adjusted. The 12 foot wide overwintering poly was adequate but tended not to seal at the junction with the anchor legs. Just in the last few weeks I finally found a solution to this by using 1/2" irrigation tubing stakes. These are strong (enough), cheap, and won’t rip the poly (see pic). The taller height meant greater risk to wind, and at one point before I had all the rope ties in place a couple hoops went sideways…
On two of the three tunnels I had a fruiting wire for the fig trees to be wrapped along (cordon style). This made sealing the ends difficult. Next year I think I’m going to make rigid end “caps” made of foam board and plywood that will affix to the last hoop. That way even if the poly isn’t a perfect seal at the end it won’t matter much. On one tunnel I threaded a wire through the middle/top point of each hoop to act as a purlin. One bad mistake I made was drilling the holes for the purlin wire before bending the hoop. The EMT conduit would crimp on that hole and at best you’d be left with a more gothic looking hoop… This tunnel had no structural problems but again had problems sealing on the ends.
Another “bright idea” I had was collecting the hard work of others and trying to use it for a wind break. I drove around and loaded up bagged leaves from my neighbors and placed them against the tunnel on the side facing the prevailing winds. This may have helped but it makes inspecting the seal hard. I’ll say the jury is still out on this.
Spring Complications
Because of how late and cool last spring/summer was many of us are aiming to push the action this year. I’m leaving the poly and row cover down to try the same. For those of us in the northeast the sun starts to pack some punch beginning in early February, this is also when you pass 10 hours of sun each day. From 2/14-3/18 average temp in the low tunnel was 39.3F, while outside it was 34.3F (5F difference). From 11/12-2/14 there was just a 3F difference between average temp in the tunnel and without. Now that 2/14-3/18 difference is mostly from temperature spikes in the mid-afternoon. As my last two photos show, this seems to be having an effect on an earlier bud break. I have over a month until my traditional last frost date so I’m certainly taking a risk (about the same as Apricot growers, as they just started to bloom early this week). I don’t really trust the poly, row cover to protect the figs from a hard freeze so I’ve been preparing to artificially heat if something like 27F is forecasted.
Overall
I should have given myself more time to bend the hoops and get the skeletal structure setup. Playing from behind, I never felt like I was able to get everything buttoned up properly. Thankfully this mild winter didn’t punish me too bad. The 30 trees I planted last year all suffered significant damage. In another month I’ll be able to say how much. I do think the trees are much hardier going into their second winter. Combining that hypothesis (weak first winter hardiness) with my setup issues has me considering a simplified protection for the first winter following planting, then switching to a low tunnel before the second winter.
I did build a simple plywood, foam board insulation house that could protect a 30 inch whip (affectionately known as the fig coffin). I had a temperature recorder inside but I won’t be able to read it for at least another month (covid shutdown equipment access issue). I also had a temp recorder under foam pipe insulation I wrapped around a fig whip in the tunnel. I’ll see those results at some point too.
I included a couple pics taken 3/31 of chickweed and purple deadnettle going nuts under the tunnel.
4_n|690x920 !
