Is it really possible to garden year-round?
Yes, even in Nova Scotia. Through years of experimentation, Niki Jabbour has developed an all-seasons approach to edible gardening, despite the rigors of her Halifax location, where frost can linger until late May and return in early October.
What Ms. Jabbour — an intrepid vegetable gardener and the host of the radio show “The Weekend Gardener” — calls her “vegetable garden tool kit” doesn’t include a trowel and pruning shears (although they are always within reach). Her essentials are an assortment of fabrics and the supports she drapes them over.
In a place with such a short traditional growing season, Ms. Jabbour might have been content simply to master cool- and short-season vegetables — colorful cauliflowers, every texture of kale and a diversity of add-on salad ingredients, including miner’s lettuce (Claytonia), mizuna and sorrel. But once she started down the tool-kit route, she kept pushing, then pushing some more.
Today, she counts on reliable harvests of coveted Lebanese ingredients like cucumber melons (also called mekti, or Armenian cucumbers) and perennial Syrian oregano (to make za’atar). They’re grown to delight her in-laws, immigrants from that Mediterranean subtropical zone, who now live nearby in a climate that is anything but.
In the process of stretching her growing season in both directions, Ms. Jabbour has reaped some extra harvest-maximizing benefits: She has learned how to outsmart squash bugs, flea beetles and cabbage worms, and even much larger pests, like the deer who visit daily. Her zone-cheating, season-extending tool kit, it turns out, is an effective barrier against more than just weather, and that versatility is the subject of her latest book, “Growing Under Cover: Techniques for a More Productive, Weather-Resistant, Pest-Free Vegetable Garden.”
Ms. Jabbour’s adventures in limits-pushing started simply enough, with the impromptu use of row cover late one October, maybe 18 years ago. She was planting garlic and noticed a patch of arugula still going strong despite recent frost. She covered it with some fabric she had used in spring over tomato transplants when the temperature dipped briefly. “We harvested arugula till Christmas,” she recalled.
That accidental success got her thinking. She began reading any books she could find on the topic, including the classics: books by Helen and Scott Nearing, New England homesteaders who chronicled their experiments in a series that began with “Living the Good Life” in the 1950s, and by Eliot Coleman, a gardener in Maine with 50 years of experience in four-season vegetable production, who was inspired by the Nearings and mentored a generation of organic farmers. Leandre Poisson’s “Solar Gardening” was also on the curriculum.
She searched out seed from Northern companies that listed many appropriate to her short season and began ordering the gear those authors had used. As she put it: “If you’re going to invest money and then time in the right seeds, why not invest in the insurance, too?”
Wise words for right about now, when our seeds are (with any luck) on order and the soil awaits — although it is probably still frozen or mucky. Are we prepared with the insurance, too? Ms. Jabbour suggested her most-used basics to get us started.
What Do You Want to Grow, and When?
Successful zone-cheating and pest-prevention depends on matching tools with garden goals. Is your obstacle heat, frost, insects or animals?
In a short-season area, where it’s hard to mature a full harvest of heat-lovers like peppers, eggplants and melons if frost descends early, a mini hoop tunnel covered in greenhouse plastic sheeting is an effective defense.
A crop that benefits from a certain kind of protection at one end of the season — like tomatoes that begin outdoor life shielded by a piece of row cover — may need something else at the other end. (The chart below offers a quick cross-reference to pairing tools with challenges.)
“It’s hard to have a fabric-covered mini-tunnel over a full-grown tomato plant,” Ms. Jabbour said, “so I might just wrap them in fall in lightweight or medium row cover attached to their wooden support stake. It doesn’t look so beautiful, but you can get several more weeks of ripening.”
Lightweight row cover offers defense against insects, as does that plastic mini-tunnel — but inside the tunnel it’s too hot in summer for crops like lettuce, cabbage and broccoli.
Knitted shade cloth meets another challenge, blocking some light, depending on the weight chosen, which makes midsummer seeding easier.
“A lot of crops for fall and winter harvest are planted in summer, when soil is hot and dry — which seeds don’t like,” Ms. Jabbour said. Shade cloth slows soil-moisture evaporation, aiding germination, also slowing bolting of spring lettuce, arugula and spinach as summer heat arrives.
Three Basic Materials Are All You Need
There are many weights and brands of material, but to get started experimenting, Ms. Jabbour recommends investing in three: a lightweight row cover, a knitted shade cloth and durable, clear-plastic sheeting.
When you’re buying the material, she said, “Think farmer quality. I want to use less plastic and other such materials, so I would rather pay more and have the durability.”
Start with the fabric row cover: Ms. Jabbour recommends Agribon AG-19, which lets in 85 percent of the light and is rated for insect protection and light frost, offering about 4 degrees of insulation for temperatures down to 28 degrees. For insect protection alone, the lighter Agribon AG-15 lets in 90 percent of the light, but with less heat buildup, so it can remain in place in summer.
Next, choose a black or green knitted shade cloth, offering 30 to 50 percent shade.
Ms. Jabbour’s third essential: 6-mil greenhouse-quality plastic, UV-treated and rated for a four-year life span (although she gets six or seven years’ use out of it). Garden centers may sell this by the running foot, or you can order a roll with friends. Skip the special greenhouse repair tape; cheaper clear packing tape is fine. “Just be sure to patch any holes on both sides,” Ms. Jabbour said.
When you’re not using your materials, fold and store them. But first, be sure to clean them, as accumulated dirt reduces light transmission. “I lay the plastic down and mop and hose it off,” Ms. Jabbour said. “And I hang the fabrics and hose them down, or machine wash them on delicate.”
Choose the Right Support
Various materials fashioned into hoops can straddle beds and support the covers. On Ms. Jabbour’s four-foot-wide beds, 10-foot lengths bent into hoops will rise to about a yard high at the center, depending how deep the ends are buried.
Many gardeners start with nine-gauge wire, which is more than adequate to support lightweight covers for pest control or shade. “I use wire in shoulder season or summer to float stuff on,” Ms. Jabbour said, “but not in winter.”
Half-inch PVC conduit is a step up, in easy-to-bend 10-footers. Lately, Ms. Jabbour has been upgrading to half-inch galvanized electrical conduit — the most durable support, although it requires a pipe-bending tool.
The key to a tightfitting cover on half-inch supports: special greenhouse snap clamps made for the job, about three for each hoop. In windy conditions or to keep insects out, the bottom edges must be buried or weighted down with lumber or rocks.
For mini-tunnels from which she harvests carrots, Asian greens and other crops all winter, Ms. Jabbour rolls one-by-two lumber in the hem and screws that into the raised bed’s edge.
“Even with those little screw holes in the poly,” she said, “I end up reusing it for years.”
On or Off? When to Apply and Remove Covers
To outsmart spring frosts and keep out insects, put your cover on at sowing or transplanting time. “With seeding, you could wait,” Ms. Jabbour said. “But hey, the extra warmth may hasten germination and growth.”
A caveat: Cabbage worms, flea beetles, squash bugs and other insects may overwinter in the soil in some life stage. So crop rotation — moving brassicas, cucurbits or nightshades to a new place in the garden every year — must be paired with row-cover use. “Otherwise, it backfires, and you’re trapping pests under cover with their favorite food,” she said.
Some crops require pollinator access to set fruit, so with cucurbits, for instance, Ms. Jabbour removes covers when the plants flower. “By then, they are usually robust enough to withstand a little pest pressure anyhow,” she said.
Lightweight fabrics may discourage larger pests like rabbits, woodchucks or deer. You could also invest in bird netting or chicken wire as an extra-tough cover that’s effective even when birds, chipmunks or squirrels dig seeds or uproot seedlings.
Ready for the Next Step? Try a Cold Frame
Ready to step up to something semipermanent in under-cover growing? Try a cold frame, Ms. Jabbour suggested.
A cold frame is a versatile tool — whether it’s portable or partially buried in the ground, store-bought and made of polycarbonate or built from rot-resistant wood with a poly lid. “You can start seeds, care for seedlings, push spring and fall, overwinter half-hardy plants like Syrian and Greek oregano or even my artichokes, and force pots of flower bulbs,” she said.
Ms. Jabbour has several, and enough other gear to defend and extend most of her 20 raised beds, plus a 14-by-24-foot poly tunnel tall enough to walk through. And her cloches — an impressive collection, most of them plastic gallon water bottles with the bottoms removed — are like individual greenhouses for tender transplants.
One caution about assembling your own vegetable garden tool kit: Each success may embolden you to take on another, more-elusive goal. Fig forest, anyone? Ms. Jabbour’s in-laws certainly hope that’s what’s next in the ongoing experiment.