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Growing plants indoors

Starting plants from seed is the next step to earning your green thumb

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The idea of starting transplants from seeds entices gardeners. Seeds costs less than transplants. Plus garden centres carry hundreds of seed varieties and a limited number of transplant varieties. Best of all is the thrill of watching tiny seeds grow into productive vegetable and flower plants.

Starting from seed has drawbacks though. You will have dozens of plants taking up space under grow lights for at least six weeks. They need daily care: keeping them warm, watering, turning, raising and lowering the lights. Then you may need to transplant these baby plants into larger containers that will take up more space before you can harden them off, or prepare them to be outdoors. All of this is before you plant your carefully nurtured plants in the ground.

It’s a lot of work, but the satisfaction is worthwhile. Vegetables never taste better. Flowers are never more beautiful. Give it a try; I learned through trial and error.

Choose seeds that are suitable for our short season climate. Most vegetable seed packets list the number of days from planting to production. Some specialty seed varieties’ packets contain fewer than 15 seeds (particularly newer varieties), others offer dozens. One difficult lesson is that you don’t have to plant every seed in the packet. You’ll want to, but do you really need 30 Beefsteak tomato plants? Or 100 cabbages? Share your extra seeds with gardening friends or store them in a dry, dark place for next year.

Depending on the full moons in May and September, we have approximately 139 frost-free growing days. Most seeds need to grow under lights for six weeks before they are ready to set out in the ground, so that gives you an extra 40 days.

The soil must be warm enough for the plants to continue growing outside, or they will just sit there until it is. For Maritimers, that date is usually the long weekend in May (unless the full moon falls then or later—if so, wait until the full moon is done). To know when to plant seeds inside, count back six weeks from the long weekend. Some seedlings will take longer than six weeks so be sure to read the packet.

There are innumerable possibilities for containers: plastic yogurt dishes, compostable paper cups, fancy seed-starting set-ups, and more. Any vessel will work as long as it holds 1/3–1/2 cup of soil and has a drainage hole in the bottom.

You will also need a tray to store them. I prefer one without drainage holes so I can place water in the bottom and let it soak up into the containers. Too much water can rot the seeds and cause diseases that will kill seedlings. Keep soil moist, but not soggy.

Use a soilless seed-starting mix to provide the seeds with constant moisture and oxygen. Place the mix in a bucket and add enough room temperature water to make it moist but not soggy. Fill your containers to 1.5 cm from the top.

Tamp down with your fingers and add more mix if required. Plant seeds to the depth listed on the packet, cover with vermiculite (some seeds need light to germinate so check the packet for that too) and spray with water. Cover the tray with plastic wrap and place it on a warm (not hot) surface. Label your pots and trays with the names of the plants they contain.

No matter how much light comes in through your windows, it’s not enough. This is one place you cannot compromise. Without indoor lights your plants will become leggy and weak.

You can invest in the Cadillac of lighting systems or use wooden or wire shelving with a bank of fluorescent lights under each shelf, attached with chain so that they can be raised and lowered. Use 120-cm fixtures with at least two standard fluorescent tubes.

Immediately place the seeds under the lights when they start to germinate. Lower the lights to 1.5 cm from the leaves. As the plants grow, raise the lights as needed to maintain this distance. Seeds germinate best at temperatures from 18–24° Celsius, and growing plants will thrive in that range as well.

Fertilise your seedlings when the first set of true leaves appear (usually the third and fourth leaves). Use an all-purpose liquid soluble fertiliser at half the recommended amount twice weekly.

Enjoy watching your plants grow for the next few weeks. If your seedlings are large plants, such as cucumber or squash, you may need to transplant them into larger pots, using the same soilless starting mix.

Your young plants need to slowly adjust to the outside weather before you plant them. Around week six place the trays outside in light shade, protected from wind. Bring them in each night and return them outside each morning for seven to 10 days. Then, plant them in the warm ground, preferably in the morning on an overcast day.

Starting your own seedlings is not easy, but it is rewarding and exciting. Plus it gives you bragging rights with Mother Nature.

Although you can start most vegetables inside, these are the easiest:

• tomatoes
• peppers
• cucumbers
• squash/pumpkin
• eggplant
• melons