Home Exotics Tomatoes


Growing tomatoes under glass

Tomato seedlings
Tomato seedlings fill the big propagator, end of March

I grow tomatoes to fit my climate – dull and cool, so they go in the conservatory or greenhouse, all indeterminate, or cordon varieties, which need support.

The conservatory is narrow and tall, so I need tomatoes that match its dimensions.

Seedlings usually appear in 5-14 days (see below). Once they are through, give as much light as possible (I use a grow light) and grow on in cooler conditions.

When the first true leaves appear, prick out into individual pots (my favourite yoghurt/rice cartons). Plant into large pots, grow bags or greenhouse beds from April to May.

Provide support, pinching out side shoots regularly. Pinch out the main growing tip after 5-6 trusses have set.

Here are varieties I’ve grown over the past few years and how they did:

Greenhouse tomatoes
Greenhouse tomatoes, July 2015

SUNCHOCOLA F1: Sweet, with a distinctive red/brown colour.

RED/YELLOW CURRANT: Grafted plants, a trial from Big Allotment Challenge Winner Rob Smith’s range from Dobies. He said: “It’s a different species from your common garden tomato and it’s hardly changed since it was found growing wild on a Peruvian beach in 1707. The plants are very disease resistant and can tolerate cooler temperatures. Each tiny tomato is crisp, and has a really intense, sweet/tart flavour.”

These did grow well out of doors and the flavour was great.

A day’s multicoloured pickings

ORANGE PARUCHE F1: The high sugar content gives the fruit a superb flavour. A challenge to Sungold.

PINK CHARMER F1: Very vigorous, distinctive pink fruits, good flavour.

GREEN ZEBRA: ‘Modern heirloom’ type with dark green and yellow stripes. Newer variations blush reddish instead of yellow when ripe. It is more tart than regular tomatoes, and it is an early cultivar. Produces bigger fruit than a cherry at 3oz (75g). The ‘Marmite’ tomato – my family hated it, so naturally, it produced a huge crop.

CRIMSON CRUSH F1: The world’s first fully blight-resistant tomato, with large, round tomatoes (up to 8oz/200g). It’s bred for outdoors, but can be grown indoors too.

SUNCHERRY SMILE F1: Masses of wonderfully sweet red cherry fruits with very shiny skins.

A note: The F1 varieties cost a lot to produce, so are expensive and you’ll only get eight-15 seeds per packet. However, Green Zebra is not an F1 variety, so is much cheaper and has an average of 75 seeds per packet.

potted-guide-logoPotted guide: indoor tomatoes

  • SOWING TIME: January-March (only sow very early if you use grow lights). Sow 0.5cm (¼”) deep, thinly in a seed tray and cover with Vermiculite or Perlite, 15-20°C (60-68°F).
  • HARVESTING TIME: June-November.
  • ASPECT AND SOIL: Full sun, rich, well-drained.
  • HARDINESS: Tender.
  • DIFFICULTY: Moderate.
  • RECOMMENDED VARIETIES: Orange Paruche F1, Pink Charmer F1, Rosella, Suncherry F1, Black Opal, Pink Baby Plum F1, Sungold F1 (all cherries), Brandywine (heirloom beefsteak).