When we returned home from 2 nights of camping (the first time we've left home since February), the tomatoes had completely collapsed. After about a month of heavy fog and cool temperatures, the two days we were away were the first really warm ones. The tomatoes put on a ton of growth and nearly pulled their support structure over.
This is the story of what I did wrong, and what I'm doing to fix it. Hopefully my failures can help you grow better tomatoes!
First fail: Not enough support
I've been reading for years that tomatoes need really strong supports. But until this season, my tomatoes have never gotten big and vigorous enough to need anything more than the cone-shaped tomato cages you get from the hardware store.
This failure of support is actually related to two things I got right this year for the first time: Really healthy transplants, and well amended soil with good drainage.
After I started Orta it was easy to get my tomatoes germinated from seed in our self-watering pots, but once they outgrew their seed pots, I didn't get their care quite right. Because they're such fast growers, tomatoes need to be potted up to bigger containers fairly quickly. If they get root-bound in their Orta pots, even if they're getting enough water and liquid feeds (from above, not in the reservoir!) they'll slow their growth, and won't ever be as vigorous as they would have been. This year I was very careful to pot the seedlings up early, and into a rich potting soil. The difference in the health of my transplants was remarkable.
The other thing we did right was to dig deep beds, put in drainage channels, and backfill them with native soil mixed with amendments, about 2 feet deep. You can see our whole veggie bed building adventure here, and here.
Given that I'd never gotten those elements right before, I had no idea what abundant growth these healthy plants would give me! I thought a steel rose arch would be plenty of support. For the amount of plant material out there now, I think a set of monkey bars might be more appropriate if I were to start over.
But working with what I have, I used a big rope to secure the rose arch to a nearby tree to keep it from toppling over, and then untangled and secured the individual vines to the newly sturdy(ish) arch.
Second fail: Not enough air
This is related to the lack of support described above. Tomatoes are sensitive to excess moisture and cold. Because we've had such a cool, foggy summer, the plants were getting really damp, and weren't able to dry out during the day because of the dense growth.
After I untangled and supported the vines, I went through the plants and pruned off the densest undergrowth to allow air to circulate. In the process I discovered lots of yellowing and dead leaves buried deep in the masses of vines. I'm hoping that the extra air circulation will help curb whatever fungus or disease was causing the yellowing.
Third fail: Too much water all of a sudden leads to cracking fruit
After propping up the tomato vines, their leaves wilted at the tips. I thought it was maybe because the plants had to work harder to raise water now that the plants were a few feet higher than they had been. So I gave them a good soak. Which was clearly not the best thing, because some of the fruit have started to crack. This happens when they get too much water suddenly, after a long period without. Though the wilting vines did perk up, so maybe it wasn't all bad . . .
Finally, another trick for healthy tomatoes
I learned this one on Gardener's World last week: A comfrey mulch for tomatoes. Comfrey is a classic garden helper plant because it draws nutrients from deep in the soil and concentrates them in its leaves. It's often soaked in water to make a fertilizer. But a much easier solution is to chop up comfrey leaves and mulch around the base of tomatoes, leaving earthworms and other soil life to work the nutrients into the soil.
If you don't have comfrey, and you'd like to feed your tomatoes, look for an organic fertilizer high in potash (potassium, or K in the NPK of fertilizer ratios) like a standard tomato feed. Liquid seaweed is also great. A fertilizer too high in nitrogen at this time of year will encourage lots of leafy green growth, but not much fruit.
How are your tomatoes this year?