Department of DIY: Jumpstart Your Growing Season with a Greenhouse

Last Saturday at the Sag Harbor Farmers Market, I was startled but something I hadn’t seen in months: fresh produce. But there it was. The local food purveyor Rustic Roots out of Hampton Bays was selling perfect arugula and bok choy from North Fork greenhouses. As the days warm, you may also notice something sprouting across our edible landscape: greenhouses.

Look in the backyard of Estia’s Restaurant in Sag Harbor or David Falkowski’s land on Butter Lane in Bridgehampton, and you’ll see domed structures of various sizes covered with plastic sheeting or agricultural cloth laid over beds like a toasty quilt. Greenhouses help warm the soil, shelter plants from wind and even keep out some insect pests. And most important of all, in our climate, they can extend the season during which we get fresh produce. (Geraldine Pluenneke described this nascent trend on Long Island for Edible East End in 2009.)

On the North Fork, farms like Sang Lee and Satur Farms were early adopters and today supply greens, radishes, carrots, leeks, onions and all manner of greenhouse produce to many eaters across the region. A newcomer Koppert Cress specializes in microgreens. There’s another that just grows hothouse tomatoes. And its with the aid of greenhouses that farms like Harbes in Mattituck and the Halseys on Deerfield in Watermill sell a bounty of potted plants and flower seedlings. The glass greenhouses used at Wickham’s in Cutchogue are over a century old.

These aren’t your grandpa’s greenhouse. The new generation of season-extending structures are durable, flexible and inexpensive.
There are kits of various sizes and prices you can order online. Our local Agways and hardware stores also have most of what you need to construct your own.

Which is why they’re poping up in backyards and home gardens too, including my own. With the help of Jeff Negron (famous for his work on edible schoolyards around the region), we bent 10 foot lengths of steel EMT from REVCO into 3-foot diameter hoops, stuck them into the ground every three feet and then stretched Agribon 19 over the top. This white agricultural cloth lets in light but also keeps in heat. And it’s breathable, so you can water the plants through it, unlike plastic that will shunt off rain. I’m happy to report that our greens planted just a few weeks ago are approaching cutting size, and our peas are about four inches tall. If only we had more stones and bricks to keep the edges from flapping in the wind.

TALK TO US: Share a picture of your backyard greenhouse. Tell us what tricks you use to start seeds and plants early.