Tomatoes like warmth, lots of sunshine and nutritious friable soil. Light frosts will damage tomatoes and stunt their growth. A hard winter frost will kill tomatoes.
To extend the growing season through late autumn and winter the tomatoes need to be covered each afternoon to prevent frost from settling on them. Do not leave the cover on, if made of plastic, as condensation will occur due to the warmer day temperature and this will cause fungal diseases. Alternatively, tomatoes can be grown in large containers and be either moved indoors at night or be located under cover. The sun is at a very low angle during winter so it is possible to grow them in a protected under cover position without depriving them of sunshine.
Where I live organic tomatoes cost $6.99 a kilo for medium sized tomatoes and $9.99 for a 250 gram punnet of cherry or dwarf Roma tomatoes. I don’t know about you, but those prices provide a real incentive to grow my own even not enough is grown to provide our entire tomato consumption.
This year winter is warmer than usual so our cherry tomatoes are still producing although they are starting to weaken. We are approximately 2 km from the coast so frosts are far milder than those experienced 10 km and further inland.
Since we love our tomatoes I decided to experiment with varieties that tolerate cooler weather in the hope of finding a tomato that was even more cold tolerant than the cherry tomato. In hindsight it would have been better timed to sow them in early autumn for a winter crop. However, germinating tomatoes in winter isn’t something a lot of people even try so it will still be an interesting exercise.
Winter Tomato Varieties
A seed supplier who had cool climate tomato seeds was found using Google. The choice was restricted to three varieties although the urge to try more was strong. The seeds chosen were:
- Kotlas (Sprint) – *Heirloom tomato – Very cold tolerant, blight resistant
- Red Russian *Heirloom tomato – Vigorous, tolerates low night temperatures, tasty
- Legend – Early slicing tomato that will fruit even in cold weather
In my haste to obtain seeds I inadvertently overlooked the certified organic aspect. This seed company states that they are grown by certified organic growers and non certified growers – all of whom do not used pesticides, herbicides or fungicides. They used biological, natural and organic growing methods. I would have preferred certified organic seeds but lost the plot somewhere along the line.
Seed Raising and Germination
Organic compost was mixed with a generous dollop of rich compost worm castings and placed into three old used seed punnets. On the 9 June 2013 each punnet had half a dozen seeds sown.
Each morning the punnets are placed outside in the sun and in the late afternoon they are taken indoors. The temperature indoors has usually been between 12 and 18 degrees Celsius overnight with an average of around 14 degrees. There were a couple of nights at 10 and 12 degrees indoors. The outdoor temperature has averaged around 16 to 18 degrees during the day. Overnight the lowest temperature was 3 degrees. The climate here is a subtropical/temperate overlap. This winter has definitely been a mild one. The compost mixture was watered as required to keep the compost moist but not wet.
The Kotlas and Legend tomato seeds germinated after one week. A week later two Red Russian seedlings pushed their little heads through followed by another seedling a week later and the fourth seedling just a few days ago.
None of the tomato seedlings are rocketing along but that’s to be expected since they were sown at the beginning of the first month of winter. Most of the Kotlas and Legend seedlings have produced their first pair of true leaves.
The seedlings will be transplanted when they have grown a bit bigger. Each variety will have some seedlings planted into pots and some into the garden. It would be interesting to know how other gardeners experiment with winter tomatoes.
Stayed tuned for an update on the winter tomato’s progress in a following post.