replace hoophouse plastic – Sustainable Market Farming

group_build_greenhouse-924-500-400-100 — An old photo from the first time we pulled plastic in 2002.
Photo credit McCune Porter

Today we revisited the hoophouse and loosened up the outer layer of plastic. We’d accidentally pulled it too tight in our eagerness to get the task finished, and it couldn’t really inflate properly. (The air between the two layers provides insulation as well as structural strength – it stops the plastic flapping about and wearing out by rubbing on the bows). We only had a few inches spare because we had already trimmed the extra plastic off (did I say we were keen to get the job finished?) Hopefully, when it finishes re-inflating the result will be better than it was.

I’ve been busy proof-reading my book Sustainable Market Farming and I’m tired of sitting at the computer, so this post will be short on words and long on photos!

Fresh air hoophouse waiting for its plastic.
Photo credit Robbie Sproule

We tied the edge of the plastic round old tennis balls, so we could pull without tearing the plastic

We were lucky with the weather. You can see from Robbie’s picture that we had cowpeas, peppers and ginger growing at the time, and didn’t want a frost.

Here we are after throwing the ropes over the top, getting ready to pull the plastic over.
Photo credit Bridget Aleshire

Here’s the plastic rolled out along the length of the hoophouse, all tied to ropes. We’re on the far side, ready to pull.
Photo credit Bridget Aleshire

Starting to pull from the far side.
Photo credit Bridget Aleshire

Another view of the crew starting the pull.
Photo credit Bridget Aleshire

In case it’s not obvious, this amount of plastic is heavy! Our hoophouse is 96′ by 30′. The plastic was 100′ by 50′.

The plastic starts to move up.
Photo credit Bridget Aleshire

The first layer was exciting, the second frustrating. The inner plastic is made to keep Infra-red radiation inside the hoophouse and also to disperse condensation, so water-bombs don’t drop down on the workers (or plants). It seems to have a slightly sticky, textured surface, which makes the second layer harder to pull over it. Our real downfall, though, was that the grass was dewy and we thoughtlessly pulled the outer layer over the wet grass before it went over the hoophouse. This made the two layers stick together.

Here’s a great picture of the tennis-ball-in-sock being thrown over the top to pull the second layer.
Photo credit Bridget Aleshire.

So, now we have the plastic on, we have been busy inside the hoophouse, sowing turnips, transplanting lettuce and chard. And harvesting radishes, tatsoi and peppers. We’ve pulled up the cowpeas, which are a seed crop, and sown turnips in their place. We’ve started pulling up the pepper plants and soon we’ll harvest the ginger. Next week!

This week I did some research into grasshoppers, as we have have been losing lots of new seedlings (kale, spinach, beets and turnips), and the beds are leaping with little jumping critters. Definitely bigger than flea beetles, I think they are baby grasshoppers. usually we get them in mid-August, not the first part of September, but climate change is here, so things are not “as usual” any more.

I learned that we had inadvertently been providing ideal grasshopper habitat by two things we have been doing. Or rather, two things we have not been doing. Grasshoppers like tall unmowed grass, and yes, we have been very slack about mowing around the edges of the gardens this year.Next I read that if you want to keep grasshoppers away from your vegetables you could sow a small patch of grains nearby, but not too close. The light-bulb lit up! We use a lot of buckwheat and soy as summer cover crops in our raised beds and for one reason and another, some of them got over-mature and the buckwheat set seed. No doubt the grasshoppers were having a feeding frenzy there! We paid in other ways too – the self-sown buckwheat has come up in our fall crops, and been a challenge to remove before it swamps the crops. Next year, more timely mowing and tilling. (We have a mantra not to repeat the same mistake two years running.)

I read up about Nosema Locustae bait. It’s a parasite of grasshoppers that you can spray in the spring when there is a growing population of young grasshoppers. Some of them eat the bait and incubate the parasite, then other grasshoppers eat those ones, and the disease spreads. It’s an organic answer, and doesn’t give an instant result. Some people say it’s the following year after applying it, that you’ll see a diminished horde. Sounds worthwhile, to me.

Meanwhile, our main task this week has been replacing the plastic and doing major renovations to our 30′ x 96′ hoophouse (high tunnel). We scheduled this last week, but got too much rain and wind. It’s time to replace the plastic, and we also need to replace the baseboards and shore up the west wall, which has been leaning in for some time. The two layers of plastic came off fairly easily, but it’s been tough going since. All the screws and bolts are rusted up, of course.

In order to stabilize the framework, we decided to put a screw in each connector where the purlins join the bows. That’s 25 x 6! And to prop the west wall up, we got some steel tubing to make diagonal braces. Dim-wittedly, I bought connectors that only work on two pieces of tubing at right angles to each other, not on a diagonal. So I had to do some hasty shopping. We had hoped to finish before rain and before Tuesday, but I think we’ll be there longer than that. Every little thing that doesn’t go according to plan sets us back a bit more. I’ll tell you how it’s gone next weekend.

It’ll be a joy when it’s all done and cozy in there for the winter, and we have lots of salads and cooking greens. Can’t wait!

Tag: replace hoophouse plastic

Hoophouse revisited

Grasshoppers and hoophouses