Home & Garden

A seedy proposition

A seedy proposition

Author: Canadian Living

Home & Garden

A seedy proposition

When our nextdoor neighbours left for a year-long sabbatical, I, land-hungry gardener that I am, volunteered to do their garden. I filled it with plants started from seed and grown under lights in my basement. By midsummer, tall cleomes and lavatera provided a backdrop for shorter blue salvia and white snapdragons. I harvested yellow pear and cherry tomatoes and three varieties of basil. Best of all, I loved "gardening" in the basement long before the outdoor season had begun.

Not only are seeds a boon for impatient or budget-conscious gardeners, they allow you to grow a greater choice of varieties. Instead of a standard petunia mix, you can choose the precise shade of blue you want. You can grow uncommon plants, and when it comes to tomatoes and vegetables, there are scores of heirloom and new hybrid varieties that put supermarket varieties to shame.

Seed sources include garden centres and mail-order seed companies, which send out enticing catalogues in January and offer the widest selection. Order your seeds in January or early February because choice selections tend to sell out early.

Building an indoor plant stand
To start building your plant stand, click through to the next page to download the pattern.

It's all in the timing
Most seeds started indoors should be sown between March and April. When-to-sow information is usually given on the back of seed packets. You should sow tomatoes, for example, six to eight weeks before the last frost date (the date it's safe to plant frost-tender annuals outdoors in your area). If you don't know the date, contact a nursery in your area, or check your library for Environment Canada statistics.

Avoid sowing too soon; you'll wind up with spindly plants competing for light, water and fertilizer weeks before it's safe to move them to the garden. To determine sowing dates, count backward from the last frost date and note on a calendar what to sow when.

Page 1 of 3 – On page 2, you'll discover the proper kind of lighting for starting seeds inside the house.

The right stuff
Seed-starting supplies are available at garden centres and hardware stores, and from seed catalogues. Propagating kits come with cell packs; trays or flats that catch draining water; and plastic dome lids that keep soil moist until germination. Containers, including plastic pots and multipacks from nurseries, may be reused every year provided they're washed with hot, soapy water and a little bleach (nine parts water to one part bleach). Containers should be at least four to five centimetres deep and must have drainage holes.

Lighting the way
To grow and thrive, seedlings need bright light, which they're more likely to get under fluorescent lights than on a windowsill. Our easy-to-build plant stand has three standard hanging fixtures (each with two 48-inch tubes), available at hardware or building-supply stores. The lights hang from chains, so you can adjust their heights. You don't need expensive grow lights; the standard cool white 40-watt fluorescent bulbs provide adequate light for seedlings. You can put the plant stand in any heated room. For ease, plug lights into a timer set to run for 18 hours beginning at 6 a.m.

Getting ready to sow
There are two ways to plant: sow individual seeds in the containers in which they'll grow until they're ready to transplant to the garden, or sow many seeds in one container, allowing them to grow together for several weeks before transplanting each seedling to its own cell or container.

The first method eliminates the job of transplanting fragile seedlings. It's ideal if you're raising small numbers of plants and don't need to conserve space under lights, and is preferable for large seeds that grow quickly. For tiny, slowgrowing seeds, such as begonia, the second method is a space saver.

Generally, you'll want to end up with one plant per container, but some annuals, such as lobelia and portulaca, and herbs, such as thyme and chives, can be grown and transplanted in clumps. Many seedlings look alike, so it's a good idea to label containers with a waterproof marker.

Page 2 of 3 – Build your own plant stand with our free instructions on page 3.

Planting mixes
The mix recommended for starting many seeds is actually a combination of sterile, finely ground peat moss and vermiculite that contains no nutrients. It's ideal for most small seeds that will eventually be transplanted to larger containers. You can keep seedlings in the sterile starter mix until they're ready to go outside, but if you do, you'll need to fertilize them more intensively than if you had transplanted them to potting soil. (Don't use garden soil. It can be contaminated with weed seeds and disease spores.)

If you prefer to keep seedlings in one container until they're ready for the garden, you can purchase a mix of peat moss and sterile soil that's labelled as suitable for seed starting. It contains some nutrients seedlings will need during their indoor life.

It's difficult to moisten seed starter mix with regular watering, so always dampen it before sowing. (Use one part water to four parts soil.) Put some mix into a clean plastic pail, add warm tap water and stir well. Wait several hours for the water to be absorbed. The mix should feel like a squeezed-out sponge - damp but not wet - when ready.

Seedling care
Fill each container with the mix, then tamp the top but don't pack down hard; the mix should settle about six millimetres below the rim. Follow directions on the back of the seed packet. Most seeds do well between 18°C and 21°C. Sow seeds in properly moistened mix, then cover each flat with its plastic dome to keep seeds moist enough to germinate; set flats under lights. Check regularly; do not allow seeds to dry out.

Seeds that need light to germinate should not be covered with soil mix. For those that need darkness, cover the flat with a piece of cardboard or newspaper. All seeds need light as soon as they sprout so check them daily: some spring to life in less than a week, while others take several weeks. After germination, remove the plastic domes to prevent seedlings from succumbing to disease due to excess humidity. To raise healthy seedlings, adjust the lights, always keeping the tubes five to 7.5 centimetres above the seedlings to prevent their stems from stretching and weakening. If seedlings at the outer edges lean in toward the light, reflect more light toward them by taping a length of aluminum foil along each side of the fixture. Rotate cell packs periodically so all seedlings get even light.

Check trays daily for moisture, but don't overwater. Before a seedling develops its first true leaf, it develops two cotyledons, or seed leaves, which contain stored food that gives the plant its start. Once the true leaves appear, feed seedlings weekly with a water-soluble houseplant fertilizer, such as 15-30-15 or 20-20-20, applied at half strength.

Hardening off
Plants grown indoors need time to adjust to the rigors of outdoor life. A week before transplanting to the garden, set flats outdoors in a sheltered, shady area, such as the north side of your house, first for half a day, then for longer periods, gradually moving them to sunnier, windier areas. For the first few days, bring them inside at night or cover them with an old blanket supported by overturned pots or cement blocks, then leave them outside overnight uncovered. Cold-tolerant plants, such as pansies and cabbages, should be hardened off about a month before tender heat-loving ones, such as peppers and tomatoes.

Building an indoor plant stand
To start building your plant stand download the pattern by clicking here. (PDF format requires free Adobe Acrobat Reader)

Plant stand designed by Ken Balcer, Sandi Construction, Oakville, Ont. Diagrams by Vicky Elsom.

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Home & Garden

A seedy proposition