Hi can you grow tomatoes on your windowsill to grow outside on 22nd March and beyond? I tried a few years back and got some tasty tawny tomatoes (Can't remember the date I planted) But have tried some different tomatoes this year late March but nothing seems to be growing! The windowsill is sunny everyday. Have i got the date wrong can anyone help me?

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    When did you plant the seeds this year?
    – Stephie
    Mar 22, 2021 at 16:01

1 Answer 1


In eastern North America I have tomato seeds germinating just fine right now. If you are not seeing any germination after a week there might be a problem with:

  • temperature: windowsills can be a bit cool overnight even when sunny during the day. I move mine to the top of my electric water heater in a sealed plastic bag overnight where they stay at 20 C minimum. Cooler than that is ok, it just takes them a bit longer to come up
  • water: keep evenly moist, this is particularly important if the surface of your seeding soil has a tendency to go crusty when dry. Crustiness can lead to seed germinating beneath the surface but unable to break through to the light
  • depth: tomatoes have small seeds, so a depth of a few millimetres is good, this will keep the seeds moist when the sun comes out and dries the surface
  • age of seed: generally tomato seed as old as 5 years will still come up as long as it has been stored in cool and dry conditions. The older the seed, the fewer will germinate
  • source of seed: if this is seed you saved yourself the seed must have been collected when the fruit was fully mature. Immature fruit can yield immature seed which looks fine but does not germinate readily. Mostly, commercial seed is reliable, although seed merchants are prone to mixing up old seed with new and relying on an overall germination rate to demonstrate good seed
  • Seeds need to be warm to sprout. I had a gas oven with pilot light that was around 90 F, everything sprouted fast . Mar 22, 2021 at 18:11

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