Jump to:
Tomatoes are a productive crop that gives a good yield without taking up too much of your greenhouse. To top it all off, they’re relatively easy to grow—and we’re here to help you get started with the basics. Ready?
Basics of Growing Tomatoes
Tomatoes don’t take much effort to grow, but they need regular tending, like watering and feeding. They’re also tender perennials, meaning they won’t handle frost or cold temperatures well, so they’ll need protection. For that reason, you will want to grow them in a greenhouse. But this bit of care is well worth it, especially when you pick your home-grown tomatoes in summer at their sweetest, juiciest best.
There are loads of British tomato varieties to choose from, which is a great perk of growing your own—you get far more choice than in the supermarket. This includes the classic (your familiar favourite), small and sweet cherry tomatoes, cocktail tomatoes, plums and baby plums with their oval shapes, and beef tomatoes, a.k.a. the big and meaty ones.
If you’ve decided what kind of tomatoes you want to grow (though feel free to experiment with different types!), proceed to the next step.
Grow Greenhouse Tomatoes in Two Ways
There are two ways to grow your tomatoes in a greenhouse: cordon and bush—according to the variety.
Cordon (indeterminate) tomatoes grow tall and need sturdy supports. They don’t take up much ground space but need regular care, including watering, feeding, tying to supports, and removing side shoots.
Bush (determinate) tomatoes stay compact and are for smaller spaces. Trailing types work well in window boxes and hanging baskets. They’re the easiest to grow, requiring little maintenance beyond watering and feeding, though heavy stems may need support, like sticks to hold them up.
Most popular UK tomato varieties are cordon types, but some, like Roma plum tomatoes, are bush.
Tip: Always check the seed packet or label to make sure it fits your space before buying.
Sow Tomatoes (Indoor to Greenhouse)
(Image Credit: Wikimedia Commons)
Sow tomato seeds ½ inch deep and 1 inch apart in pots. They need a soil temperature of 21-27°C (70-80°F) to germinate and grow best at 18°C (65°F) as seedlings. Vining varieties should be spaced 90-120 cm apart. For support, start with BBQ sticks, then switch to stakes, cages, or a trellis to keep the plants growing off the ground.
Keep the pots in a bright spot, on a heat mat, or under grow lights if natural light is limited. Tomatoes need at least 8 hours of sunlight per day. Seeds should germinate within 5-7 days if conditions are right.
After two weeks, they’ll be ready to move to the greenhouse. Be careful not to disturb the roots when transplanting to keep them growing strong. Water the seedlings regularly and continue throughout the growth process until harvest.
You can start harvesting when the tomatoes are full, glossy, and beginning to change colour. To improve quality, consider limiting each plant to six fruit trusses (clusters).
Tips: Pots, troughs, or greenhouse borders all work for tomatoes. Containers need to be deep enough with plenty of soil. If using pots, make sure they have drainage holes to prevent waterlogging.
Check out this guide next for more: 5 Best Plants To Grow In Your Greenhouse
