Growing from seed
Whether you yearn for a flowerbed full of colourful annuals, a kitchen garden brimming with healthful vegetables or to be the first on your block to produce a prize-winning, giant pumpkin, growing plants from seed is an economical and rewarding way to get started.
The seeds of many annual flowers and vegetables can be started indoors, several weeks before plants arrive at the garden centres, giving you a head start on the season. Another advantage of growing your own plants is the wide variety available in seed packets. Petunias come in velvety reds and azure blue, with ruffled edges or double flowers. You'll find purple beans and zebra-striped tomatoes as well as specialized mixes for sunny borders or wildflower meadows. Choosing what to sow will be the most difficult step of your project. Drop into a Home Depot garden centre and we'll help you make the right choice!
Whether you go big or start small, you'll need enough space for the trays or pots of seedlings. If you have the room, a two- or three-tiered plant stand fitted with full-spectrum, fluorescent grow lights (or a combination of cool and warm whites) is the simplest option, but an empty bookshelf or countertop with enough overhead room to hang a fluorescent light fixture will work too.
Containers or trays specially designed for growing most kinds of seeds are typically made of plastic and fitted with cell packs or with moulded channels, and topped by a clear dome. Biodegradable peat pots, which can be placed directly into the ground without disturbing roots, are suitable for seedlings that don't like being transplanted. But peat pots dry out quickly, requiring more diligent watering. Whichever you choose, containers should have good drainage and plastic ones should be meticulously clean.
Soilless mixes specially formulated for sowing yield the best results for most seeds. Lightweight, low in nutrients and freely draining, these sterile growing media provide ideal conditions for germination. Before filling trays or pots, make sure the soilless mix is moist; if it's dry, add hot water to the bag, enough to moisten the mix, and allow to cool before sowing seeds.
Some seeds need to be soaked, nicked or chilled to encourage them to germinate; others require darkness or exposure to light. Follow the specific instructions on the seed packet before sowing. Once seeds have been sown, it's important to keep the growing environment moist by covering trays with a plastic dome or enclosing pots with sealed plastic bags.
As the seeds germinate, they'll produce a pair of young leaves. This is when seedlings should be introduced gradually to light (if they've been in darkness) and to air (remove the dome or bag for a few hours, increasing exposure each day until fully exposed). They'll also require frequent monitoring to ensure the soil stays moist but not waterlogged.
As the seedlings grow, the pair of fledgling leaves is replaced with three "true" leaves, signally the time for transplanting into larger pots with a richer potting soil. This delicate procedure can be done with a pencil or special dibble, which helps ease the seedlings out of the soilless mix without disturbing their roots. Once planted into the larger pots filled with potting soil, seedlings need to be fertilized at half the recommended strength to begin with, then at full strength after about three weeks.
When the soil in the garden has warmed up and all danger of frost is past, gradually acclimatize the seedlings to the outdoors. Place them in a shady spot sheltered from winds for a few hours, and increase their exposure by a few hours each day for about a week before planting in the garden.
