Hi, I just joined today! Maybe someone can help me sort out the factors involved in transplanting tomatoes. I've been told that if tomatoes are exposed to temperatures below 12 degrees C it slows the production down by two weeks. I can't afford that with my season (Sherbrooke, Québec: frost in September is not rare). I am also informed that tomatoes transplanted when in flower (or with fruit on them) will not establish well and will yield poorly. Between these two constraints, I wind up not knowing what to do. This year I started them (varieties Brandywine, Savignac and Moskvich) two weeks later than usual, in early April, but since I started them in a greenhouse which was quite warm (between 25 and 30 degrees C), rather than in my coolish house, they caught up and they all have flowers on them, again! And I see they're still announcing nights as cold as 6 degrees C in a week's time. Definitely below 12. So I have a series of related questions: Should I just plant them out and not worry if it goes below 12 degrees? (They're in the greenhouse getting bigger and bigger and flowering away!) Do I have to pinch the flowers off before transplanting? Is it even any use doing that, or is the fact that they reached the flowering stage the problem (i.e., will they "remember" that they have flowered and will the yield be affected by that simple fact)? When should I be starting them (in the greenhouse mentioned above) so they won't be in flower in early June? Thanks for any help anyone can provide!
Tomatoes are pretty forgiving except for frost. They like hot sunny conditions. I am always trying to push the season, with and without success. My view is as long as the temperature stays above 8 C they will survive with no ill effects, otherwise cover them for the night with a 5 mil plastic bag or even a yard bag over a wire support. Planting with tomatoes on the vine has always worked for me. Last year I had tomatoes on 3 June and one or two a day until they really started producing in Zone 5 I think Sherbrooke is Zone 5 also. A prolonged cool period of a week or ten days certainly slows them down. My best crop was when I planted them on 15 June one year, but that may have been just a good year for weather. Conclusion: Cover at night and leave the cover on in the morning until it warms up a bit, then remove for the rest of the day. As I mentioned they will not tolerate any freezing. The tips of the leaves wilt and it takes them too long to recover in our cold climate. Durgan.