How to Start Tomatoes and Capsicums Indoors

How to Start Tomatoes and Capsicums Indoors

Getting a head start in your veggie garden may involve a bit of beating Mother Nature at her own game. Waiting till conditions are good for growing Tomatoes and Capsicums from seed outdoors delays your first harvest of the season. Get a head start by persuading your seeds it’s summer while the frost’s still on the ground. Plant your seedlings out after the last frosts, and your crop is much further advanced than it otherwise would have been!

Convinced? Looking to get a head start on summer? Then this blog post is for you. But before we begin, let’s just note that this is what smart horticulturists have been doing for centuries! We’re always thinking ahead to the next season, or even the season after next – and we’re looking to maximise our results. Now, it’s time to get the inside track on how to do this little sleight-of-hand trick!

How Indoors is “Indoors”?

If you’re a bit dismayed at the thought of transforming a room in your home into an indoor growing area, do remember that “indoors” could mean a greenhouse, a cold frame, or even just a sunny windowsill or corner on your veranda (if your climate is relatively mild.) And even in the harshest climates, germinating seeds doesn’t take up much indoor space. Once they’re up and growing, you can look at moving your seedlings out to space that isn’t quite in your house, but still offers good growing conditions.

Back when I was doing wholesale seedling production for nurseries, that’s just what we did. We used the best of our greenhouses for germinating summer seedlings in winter. Then, we moved them into a slightly less-well-heated polytunnel to grow on. By the time spring was underway, we could offer a range of gorgeous seedlings, already growing strongly, to our clients. Of course, the added effort contributed to pricing, but if you do this yourself, you stand to save because you don’t have to pay for nursery-grown seedlings.

Let’s get started!

Pick your Time

How early you start will be determined by how much space you have and when the last frosts are expected. Most gardening blogs suggest a time 6 weeks before the last expected frost for indoor sowing. But you can make it earlier if you have enough protected space for your growing plants.

Germination temperatures are the first challenge you face, and growing temperatures can be rather lower once the seedlings are up. Mostly, it’s just a matter of ensuring that your tender seedlings don’t frost to death once you’ve got them to come up. So, germination is the most sensitive time, and after that, you can take a few chances as long as temperatures don’t drop to levels your plants will find super-cold.

For Capsicums, you’ll need to keep growing temperatures at or above 13 degrees C for growth, while germination requires soil temperatures of just over 20 degrees. Tomatoes want soil temperatures at or over 18 degrees for germination, and the young plants will need temperatures over 10 degrees to grow.

Pick Your Containers

Local conditions, and the amount of space you have, will contribute to your container choices. Starting your seeds in compartmented trays or flats with one plant per compartment can be rather space-intensive, but it’s a good way to go if you don’t want the task of pricking out and do have the space. As an alternative, you can sow your capsicum and tomato seeds rather densely in un-compartmented trays and prick them out into compartmented flats once they have one or more pairs of “true” leaves.

Provide Bottom Heating

Nowadays, we look at electric heating cables or heated water to provide bottom heat. Sounds ambitious? The former is actually pretty easy. You can get simple, bottom heating pads for horticultural use that are intended for hobbyists. Place them under your trays, and voila. The alternative is a greenhouse with bottom heat built into the beds. That’s what professional growers do, and it needn’t take that much space either.

Back in the old days, cold frames were commonly used for starting seedlings early, and bottom heat was provided by placing rotting compost under the trays. As the compost continued to break down, it provided heat, and the seedlings were able to grow.

Whichever method you choose, use a soil thermometer, or even a meat thermometer to check the temperature. Warm enough? You’re good to go!

Water Well, But Don’t make it Soggy

Whenever you’re germinating seeds, you’re looking for “moist not wet” conditions, at least, most of the time. Right after you’ve watered, you want things to be wet. Then, you’ll let the trays dry out a little – just so that they feel like a squeezed out sponge. Now, you watch for surface drying, and water again before your germinating seeds can dry out.

Sounds tricky for your indoor growing of tomatoes and capsicums? It needn’t be. At the least, you’ll have a drip tray under your flats to catch water that runs through. You can even use your drip tray for watering from below. Fill it, and let the soil absorb the moisture. Just remember to empty drip trays once you’re satisfied that the soil is wet enough.

Of course, you can also use a spray bottle to moisten the soil. You might get a bit of a cramp in your fingers if you have a lot of trays to water, though.

Your Plants Need Good Light

Your seedlings have sprouted. Now they need light! You can choose purpose-made grow lights, or you can go with cool white fluorescent light, but whichever you choose, you need the lights to be just above the leaves (10cm will do). In very small scale seedling starts, a sunny, North-facing windowsill might be good enough – no fancy setup needed!

If you’re working with a glass or plastic covered greenhouse or cold frame, you may not need any additional light at all. Just remember that if you’re using shelving, lower shelves mightn’t get enough light.

Feeding Your Babies

Nutrition is vitally important to young seedlings. Think of human babies: if they don’t get the right feeding, they won’t be healthy and reach their potential. Your baby capsicums and tomatoes will need feeding too. Since they’re rather delicate while they’re young, you’ll go for a liquid feed over and above any slow release fertiliser you incorporated into your seedling growing mix.

I like to feed my seedlings every time I water them – after all, I won’t water them every day. And liquid feeding is safe. Provided I mix the feed properly, I won’t get any burning or overfeeding. Since flats are – well – flat, and you’re watering a fair amount, nutrients in potting or seedling soils tend to wash out rather fast.

Transplant and/or Harden Off

If you sowed your seeds in trays without compartments, you may need to transplant them into compartmented flats if you’re still expecting a chance of frost after they’re up. Protect them from the cold and give them a little extra water after transplanting to overcome transplant shock.

If you sowed in compartmented trays, or once your pricked out seedlings have recovered from transplanting, getting them used to strong, natural light is part of your work. In early spring, I don’t usually find the transition from good, indoor light to outdoor light too hectic, but if you’re worried, move your flats to a place with strong, indirect light before making the transition to sunshine. Two weeks is usually enough to get your indoor-grown tomato and chilli plants ready for the outdoors.

Another method I’ve used is to plant them out (provided you aren’t worried about hard frost) and cover them with a frame covered with light shade cloth or greenhouse plastic. If frosts are light, the cover will be enough to protect the plants while they’re also getting used to outdoor conditions.

Extra “Go” in your “Grow”

Starting your summer crop indoors gives you a head start on summer. Just thinking of those long, warm, days, and your early crops of tomatoes and capsicums should be motivation enough. OK, so some of us like winter – but there’s still something special about spring, and those early crops are sure to be a delight! Earn bragging rights and an extended growing season by starting your first tomatoes and capsicums indoors. It isn’t really difficult, and with our tips to help you, we hope to see your early harvest being a huge success.

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