We're just starting our first round of seeds at Reclaim Farm, beginning with our peppers and herbs. In late March we'll move onto tomatoes, kale, broccoli, and other vegetable starts. Once it begins to warm up outside the seedlings will spend more and more time outside each day until we transplant them sometime after the last frost.
If you're interested in growing a garden this season starting seeds indoors is a great way to get a head start and save some money (seeds are much cheaper than seedlings!). We'll give you a few of our tips in this post and keep you updated as our seedlings grow throughout the season.
Materials: Potting soil, trays, cells & pots (or make your own), grow/shop lights or a sunny south facing window, good quality organic fertilizer (kelp or fish fertlizer work well) - see our souce list post for more details
Plant seeds according to packet instructions in moist potting soil, label the plants, cover the tray with a plastic dome, and keep them in a warm place (20-25°C: on top of the fridge, on a heat mat). Place 1-3 seeds in each cell (or use a container with holes in the bottom). You can either pinch out the weakest/smallest plants later or separate them into individual pots once they get big enough. The package will also tell you when to start your seeds – count backwards from the last frost date, which is May 7 in Edmonton (on average - note this varies depending on where you live). That being said, the May long weekend is usually the time when tomatoes, peppers and other warm season crops are transplanted outside because the risk of low night time temps is greatly reduced by then. Based on this, we usually start our seeds on:
Peppers, Herbs (rosemary, thyme, mint, sage, basil) – Feb 15-25
Tomatoes – Mar 20
Keeping the seeds moist is critical for germination, so keep the soil damp but not soaking wet. Once the seed leaves/cotyledons have emerged, water every few days and don’t let the soil dry out. Lift up the cells/containers your seeds are planted in and put about 1 inch of water into the tray below. Watering from below means the plants get water right where they need them (the roots), which helps reduce fungal problems in the plant.
Most seeds germinate best in the dark (double check your seed packets to be sure) so don’t turn on your grow lights until the seedlings emerge. Once the first leaves emerge, keep the light about 2-3” away from the plants and set a timer (or manually turn on/off) so the plants are under light for about 14 hrs a day. Keeping your lights on a chain allows you to lift them as the plants grow. Placing the light close keeps the stems strong, but you don’t want any of the leaves to touch the light or they will burn. You can also point a fan at your seedlings for a few hours each day to help strengthen the stems and keep fungal problems at bay.
As an alternative to using a grow light, you can put your seedlings in a large, sunny south-facing window. Rotate them regularly as they will grow towards the sun. A word of caution though – if your seedlings don’t get enough light they will become “leggy” and the stems will be weak, so only use your sunniest windows.
When your seedlings develop their first set of true leaves (note these are the first two leaves that grow after the first seeds leaves/cotelydons), it’s time to move them into a larger container. Select a pot that is a few inches wider in diameter and has a few holes in the bottom for drainage/watering.
We usually pot up from cells to 3-4” diameter pots and keep the plants in this container until transplant. Gently squeeze the bottom of the cells to release the roots so the plant comes out into you hand. This works best if the soil is a little damp. Try not to handle the stem – if you accidentally damage a few leaves it’s not a big deal, but if the stem breaks the plant will not continue to grow. Carefully place it in the new pot, fill in the soil around it, and give it a good watering. At this stage it’s a good idea to start watering with a liquid organic fertilizer every two weeks.
For tomatoes – always re-pot (or transplant) as deep as possible to maximize root strength. When potting up you can pinch off the lower leaves and plant them as deep as possible in their new pot, leaving just the top 2-3 leaves exposed and covering the long stem with soil. The buried stem will begin to grow roots, which makes your plants stronger. If your plants get leggy you can pot them up into larger pots a couple times to encourage root strength.
Once daytime temperatures hit 8°C+ (late April / early May), you can start bringing your plants outside so they can adapt to outdoor conditions. Start by bringing them out for just an hour or so in a shady spot and sheltered spot that doesn't get much wind. Each day, leave them out for about 30-60 minutes longer than the last day, until your plants can stay outside all day long. Slowly move them from a shady/sheltered part of your yard to a sunny and exposed part. The process should take about two weeks. If your plants show any signficant sign of stress (wilting or changing colour), slow down a little and make sure they aren’t drying out (they will dry out quicker in sun/wind). Once nights are consistently above 8°C (usually mid May) and your plants show no sign of stress after being left out all day you can start leaving them out overnight.
After the plants have successfully spent a few nights outside and the danger of frost has passed (after May 7 and check the forecast!), you can transplant outdoors. Transplanting on a cloudy but calm day is ideal as it reduces the chance of transplant shock. You can also work in the evening after the hottest part of the day has passed. Pick spot in your garden with good soil that gets lots of sun. Dig a hole that is slightly larger than the transplant and add some compost or a little bit of mild organic fertilizer. Squeeze the bottom of the pot to release the roots so the plant falls into you hand. Place it in the hole and fill the soil in around it. Always give new transplants a nice soaking.
You can also transplant your tomatoes and peppers into 10-12” diameter pots and keep them in a sunny spot on your patio. Note: pots dry out more quickly than plants in the ground, so water every few days or more if it’s hot and sunny.
We're still learning ourselves, so here are some other resources:
Washington State University - Propagating Plants from Seed
Check out our other post on sourcing to find out where to get supplies and send us a message if you have any questions!