Starting Tomatoes Indoors

There’s nothing quite as perfect as a ripe tomato – that distinctive fresh, green smell of a sun-warmed fruit that bursts in your mouth. It speaks of the summer’s heat like nothing else in the garden, but it does require starting tomatoes indoors.

Starting Tomatoes Indoors

If you’re yearning for that fresh tomato taste, you have a few months to go. But there’s something you can do to prepare. By planting your tomato seeds indoors, you’ll give them a head start on growth, helping them become big, vigorous summer tomato plants.

While you can often buy tomato plants at the garden store in the springtime, growing your own from seed allows you to try one of the many intriguing heirloom varieties that go far beyond the little red cherry tomato.

Tomatoes are divided into two rough categories. Bush tomatoes give fruit around the same time and have shorter plants, while vine tomatoes bear fruit over time and tend to have taller plants. There’s plenty of diversity within these categories as well. Tomatoes vary in colour, size, shape, flavour, and time of ripening. The delightful thing about growing your own is that you can experiment with many different kinds to see what works in your garden.

Before you choose your tomato seeds, think about why you’re growing tomatoes. This will help guide you through the many tasty and tempting-looking choices that are available. Are you growing for grazing? Cherry tomatoes that vine (like Certified Organic Sweetie) might be your best bet, since they’re snack sized and produce fruit throughout the summer. If you’re growing for canning, you can look for paste tomatoes or firm canning tomatoes. Bush varieties like La Roma or Manitoba produce abundant fruit at one time, so they’re ideal for those who’d like to aim for a single summer canning session.

Think about your growing conditions as well. Tomatoes want a warm, bright place to grow, and it’s best if you situate them close to the house for easy watering. If you’re new to growing tomatoes or have a cooler climate, choose sturdy varieties like Bonny Best or Early Cascade. If you’re feeling uncertain about how the weather will play out over the summer time, get bush tomatoes that ripen at different times or throw in some vine tomatoes as well, just to make sure that whatever the weather, you’ll have ripe tomatoes throughout the season.

Now that you’ve made your choice, it’s time to set up a place where your seedlings can grow. Tomatoes adore the heat, so much so that heat, not light, is often their limiting factor. When you’re starting your tomatoes, you’ll need to provide this heat for them. If you provide them with a heating mat or seedling germination tray as they germinate, your tomatoes will usually start to sprout in one to two weeks.

The best time to sow tomato seeds is mid-March to early April. By the time the weather begins to warm in June and July, you should have plants that are large and tough enough to withstand the weather in the great outdoors. When the time is right, sow your tomato seeds in pots in a high quality seed starting mix. Dampen the soil so that it’s moist but not squishy to the touch, and sow two or three seeds ½ to 1 centimeter deep. Keep your seedlings close to a grow light or in a very bright window, so that they don’t have to reach for the light.

When can you transplant your little tomatoes out into the garden? It’s all about temperature. Early tomatoes can be planted outside when nighttime temperatures rise above 7°C (45°F), while all other tomatoes prefer night time temperatures of 10°C (50°F) or higher. Stay on the safe side, as tomatoes really dislike the cold.

When the weather has warmed up, transition your tomatoes into the outdoors by hardening them off, getting them used to the wind and weather. Place the seedlings in a sheltered place outdoors for a few hours every day, gradually increasing this over the course of about ten days. After a week, begin to leave them outdoors at night, unless the nighttime temperatures are still questionable.

When it’s time to move the seedlings into the soil, it’s important to give your tomato seedlings a solid foundation. Tomatoes are notorious water hogs, and a good root system will help them soak up enough water to get through those hot summer days.
Tomatoes can grow roots along much of their stem. When you move them to the garden, bury the stem up to the first set of true leaves. Your tomato will thank you for giving it a solid start.

Starting your tomato seeds indoors allows you to grow a wide variety of sturdy plants that are ready to meet the elements. By choosing tomato varieties that work well with your garden conditions and starting your tomatoes early, you’ll have the best chance of having a homegrown ripe tomato in your garden salad this summer.

Is this your first year to try growing tomatoes from seed? Check out our Complete Indoor Growing Kit and other Seed Starting Supplies.

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