Wednesday, March 9, 2011

Reader's Questions, Part II

#1: I've had a problem w/something eating the tomatoes (see photo above), usually the day before I planned to pick the fruit. Is there something I can spray/put on the tomatoes to repel pests?

Answer: I've had the same problem before ... to me, this looks like rat damage from Norway rats (or roof rats or fruit rats). If you live in a neighborhood with lots of fruit trees, there are going to be fruit rats outside, and guess what? They like tomatoes. Rats typically eat tomatoes at night, leaving dime- or quarter-sized holes in the fruit, ruining that piece of fruit. Personally, I don't spray for rats—it's never got bad enough that I had to worry about it, and I figure they can take a few and it won't really hurt me much. If I had to spray for them, I'd probably test a homemade garlic or cayenne spray on a few tomatoes to see if it hurt them, then try that as a deterrent.

#2: About the container size. I see where you suggest 10 gallon. What would be a good source of something

this size?

Answer: I buy used 25-gallon tree containers from a local tree nursery for $5 each. I'm not overly concerned about the look of my tomato containers, and I like the big ones, so it's usually a simple matter of asking if they have any old ones laying around that I can take off their hands. You can also buy large (and much better looking) containers at most big-box stores. Remember that a cubic foot equals about 7.5 gallons, so it will take about two cubic feet of soil to fill a 15-gallon container. If the container isn't labeled for size, use its soil-holding capacity as a general guide and remember: the bigger, the better.

#3: Will picking your tomatoes on the earlier side reduce pressure on the plant and allow it to set more fruit? I have a bunch in the light red phase right now, but due to the cold weather, not a ton of green fruit coming on. Wondering if picking will allow the plant to make more tomatoes?

Answer: Not really. Indeterminate tomatoes will continue to produce fruit as long as the vine is still growing. However, you can produce larger fruits by removing some of the flowers so the plant puts more energy into the fruits that remain. Also, topping your plants will encourage larger fruit and (obviously) stop new tomato production.

#4: My biggest frustration is with my tomato plants the past 2 years. I grow them in ground, they grow up as healthy large plants. They produce plenty of flowers-but before they have opportunity to fruit-something is eating them. Whatever it is seems to occur at night-the buds are nipped off one after another, only the flowers-the rest of the plant is fine. I have sprayed 'Safer" organic spray over the flowers and is not helping-more flowers have been eaten. I reviewed your blog but did not see anything mentioned regarding what pest could be causing this.

Answer: This was a stumper for me. I figured maybe some kind of beetle or caterpillar was active, so the standby treatment is bacillus thuringiensis (BT) for chewing insects. But honestly … I never did find a bug that targets tomato flowers specifically at night. If you are the author of this question and feel like jumping in, I'm very curious: whatever happened in the end? Did you take care of the issue and set some fruit after all?

#5: I'm worried about the cold front coming through early this week.What is the best way to protect them?

Answer: Ah, cold damage. This is persistent concern for us as we typically have at least one or two cold fronts pass through each year (although we've probably seen the last of our cold weather this year). In general, tomatoes can withstand down to 50 degrees without too much trouble, although they will likely stop setting fruit. If the weather is going below that, water the plants before the night sets, then cover the plants during the night. I've also seen people wrap their plants with LED holiday lights, which give off just the tiniest bit of heat, and it really seems to work.

#6: Since you use concrete reinforcing mesh for your cages, I'm curious if the rust on them is a concern?

Answer: The rust itself isn't a concern, but it's definitely best to keep your tomatoes off the wire supports. A tomato rubbing against its cage will cause misshapen, scarred and rough fruit.

And #7 … This question has been posed in various ways by lots of people, so I won't print any particular letter. And (just because I'm difficult like that) I'm not going to answer it right now either because it's a 10-pound question in a 2-pound bag. But here it is: "What are the best varieties of tomato to grow in South Florida?" You'll immediately see why it's such a big question—it's a bit like asking a parent which of their children is their favorite (the tall one? the smart one? the one that looks like you? or the one that doesn't look like you?). And it's also highly personal, because my taste in tomatoes might not be your taste in tomatoes. Nevertheless, in the near future I'll give you my two cents, for what it's worth. Which, in all reality, is just about two cents.


  1. Why does only the bottom 2/3rd of many of my tomatoes ripen?

  2. How long are you leaving them on the vine? And what happens after that 2/3 blooms? Finally, what variety are they? It's possible if you leave them on longer, they'll finish blooming. Alternatively, perhaps something is attacking the fruit before it's ready.

  3. Well, I googled the problem and all indications are that excessive heat exposure can (in many varieties) cause tomatos to stay green on top. No matter how long I leave them on the vine, the tops stay green / hard while the rest of the fruit softens / ripens and turns red. This is happening on my better boy plants and more so later in the season that earlier.

  4. Anon,

    I looked into this a bit more (I consulted my handy guide to all things tomato, Tomato Plant Culture). It looks like you're probably right ... The condition is known to growers as green shoulders and is caused by direct sunlight exposure in some varieties. I think this is a bit different than excessive heat, which we haven't really experienced yet. Excessive sun exposure often results after trimming the tomato plants. Fruits that are exposed suddenly to sun after being covered by foliage can be burned or experience green shoulders. The best protection in the future is to leave foliage on the plant to protect the plants, or if it's worth it, using netting to shade the developing fruit.

  5. This was very informative and my thanks to you for your blog as well as to your readers posting their own questions. This "green-shoulders" has been plaguing me as well!

    This is my first year growing ANYTHING since I was a kid and I am thrilled at the success I have had with different herbs and the tomatoes! I noticed splitting mentioned in relation to Big Boys- which was the variety I planted. Is that then common to that type? I will grow some other next year and I didn't find the flavor that exciting either.
    I grow mine in 18 gal containers btw.

  6. I had some damage that looked like rats. I had
    not seen any in the garden but I set traps anyway. I caught 6 and now there is no more
    damage. I suggest setting traps while fruit
    id present.