To be able to pick tomatoes from a plant when growing tomatoes on the windowsill is a great achievement! There are a number of varieties around that have been specifically bred as windowsill tomatoes. Here are some of the things you’ll need to proceed.

  • A sunny windowsill – tomatoes need a lot of light.
  • A tomato variety that will grow well in a 6 inch pot.
  • Compost that is suitable for a pot.
  • Sow at the right time
  • The plant needs to be watered and fed correctly.

Get the above right, and you can be eating your own tomatoes July/August.

A Sunny Windowsill

Tomato plants need plenty of light in order to produce flowers and then tomatoes.
Too little light – plants become leggy, spindly and lack vigour.
Another consideration is growing above a radiator. Too much heat and plants tend to shoot up like rockets – becoming leggy.

The Ideal Situation

A windowsill with plenty of light, or perhaps in a porch or conservatory, with a temperature around 18C during the day and 15C at night.

Best varieties for growing tomatoes on the Windowsill

Best Varieties for Windowsill Growing

  • Heartbreaker Vita F1
  • Balconi Red and Yellow
  • Sweet ‘n’ Neat
  • Micro Tom
  • Vilma
  • Tom Thumb

Each of the above varieties will grow in a six inch pot – I can speak from experience because I’ve grown them all!

Some varieties will produce a better crop than others. I put Heartbreaker, Sweet ‘n’ Neat and Vilma in my top three choices. However, they are all great tasting tomatoes that will bring a lot of fun and interest – a good talking point for visitors!

When to Sow Seeds for Windowsill Varieties

Because windowsill tomatoes are going to spend their entire time indoors, the seed sowing period is wider. In other words, you can sow at the beginning of March right through to the middle of April and expect good results.

A little extra light from a grow lamp or even a desk lamp when it’s cloudy outside, is one way of enhancing growth. However, it is not essential under average conditions.

Choosing The Compost for Windowsill Tomatoes

Compost for container growing can be bought from the garden centre. This is a light fluffy mix that contains vermiculite or perlite that hold both water and air.

Tomato plant roots need moisture, nutrients and oxygen to grow vigorously. Without all three, plants become stunted and under-perform.

Perlite is a great way to enhance the soil of any container and improves the health of plant roots. It can be bought separately from most garden stores.

Perlite mixed with soil to improve tomato root health.
Perlite mixed with soil to improve moisture and air in root zone.

Support for Dwarf Tomato Plants

When growing tomatoes on the windowsill, we are growing dwarf varieties.

This type of tomato plant grows upright to between six to around twelve inches.
It will need some support, especially when laden with tomatoes so it’s best to add support canes early so as not to disturb plants roots later.

Growing Dwarf Tomatoes on the Windowsill

Watering Windowsill Tomatoes

Placing the pot in a flat saucer or tray and watering from below, is the best way to water tomatoes growing in pots. This prevents the soil from becoming compacted if watering from above. The more air we can keep in the soil, the better.

The Wet/Dry Cycle

Having plenty of perlite in the root zone means that it’s harder to over-water the plant.
However, when using ordinary compost, think of watering as a wet/dry cycle.

  • The soil is saturated with water
  • As it dries, air comes back in between the soil particles

To do this successfully, you need to allow a good period of a day or two or three, depending on the temperature and light, before watering again.

The temptation is to over-water tomato plants, a bit like over-feeding the goldfish, they sometimes end up being killed with kindness!

Feeding Windowsill Tomatoes

Little and often is always the best way to feed tomato plants.

Whatever plant food or tomato food you are using, feeding half the strength but twice as often is a good way to proceed. Just as with watering, we tend to over-feed and plants under-perform. It’s better for them to be slightly under-fed than over-fed!

To Sum Up

Although these windowsill varieties are small, both as plants and in the size of tomato produced, they are very rewarding to grow. They may not produce as many tomatoes as a bigger tomato plant does, but it’s a great way to get started growing tomatoes indoors. Next season you may have a house and garden full of tomato plants!

Get Sweet ‘n’ Neat Seeds Here

See Also: Windowsill Varieties

Next: How To Grow Tomatoes in Hanging Baskets