From gardens across the area, I’ve had reports of great successes and annoying troubles. Gardeners are bringing amazing vegetables into their kitchens from some of their crops, but the usual troubles of mid-summer are beginning to appear.
First — here are some successes:
Now for some less-than-successes, which we all experience to some degree pretty much every year:
In the past week, I’ve seen for myself or heard other gardeners discuss these garden pests:
- Fruit worms on tomatoes and peppers (in my own garden)
- Pickleworms on squash, melons, and cucumbers
- Squash vine borers on yellow squashes and zucchini
More than one gardener has mentioned that all their tomato plants, except for one, look healthy. The one exception has been a plant that wilts in the day, then seems to recover at night.
Going through the steps to identify the cause, listed in my “wilting tomato plants” article, can help. Checking soil moisture and looking for stem damage are easy steps that anyone can do. The hard steps are the ones that ask the gardener to sacrifice the plant.
I understand. We love plants. Pulling them up to look at the roots or cutting them down to look inside the stem just seems wrong. However, those are the best ways to identify the problems that begin underground (nematodes and wilt-funguses). Also, leaving ailing plants in the garden can allow some problems to spread to other plants.
Problems caused by factors like the weather
Another way to name these problems is to call them “physiological”. They are the plant’s reaction to things like temperature and uneven watering (or too much rain, then no rain, then too much rain, repeat).
Blossom end rot
I see this most often in tomatoes, but Iowa State University’s article on blossom end rot says it also occurs in peppers and squashes. This looks like a dark soft spot that appears at the bottom of the fruit — the side opposite the stem — and Iowa State’s article says it is caused by a lack of calcium, that is caused by uneven watering.
Considering that I was away from home for much of May and June, it may be a miracle that I have seen blossom end rot on only a few of my tomatoes this year. Or, maybe the miracle is in the mulch that I put down before our travels began. Mulch keeps moisture in the soil longer.
Other gardeners have been less lucky; a large number of their tomatoes have this problem.
If there are squishy spots on the shoulders, up near the stem, of your blocky fruits like tomatoes and bell peppers, the cause is likely to be exposure to too much sun. In essence, the fruits get sunburned, but the specialists call it sunscald.
Avoiding sunscald is a good reason to prune tomato and pepper plants as little as necessary. (To see how I prune my tomato plants, watch the video in my article on determinate vs. indeterminate tomatoes.)
Some plants, even without pruning, do not have enough — or large enough — leaves to shade their fruits. This could mean that the plants are not getting enough nutrients to grow well.
Tomatoes not getting ripe
A lack of tomato-ripening is causing frustration among several gardeners I spoke with last week. There are plenty of big, green tomatoes on their plants, but none are turning red, even though they should be.
Depending on which state’s publications you read, in order for the red pigment in tomatoes to form, the daytime temperature has to stay either below 86 degrees F (Ohio State University) or below 90 degrees F (Arizona State University). The difference may be in the tomato varieties tested.
Nighttime temperatures also need to go below 70-to-75 degrees F for the red pigment to form.
Weirdly enough, my tomatoes are ripening on the plants, and they are growing with essentially the same air temperatures as the tomatoes of my gardening friends.
One of my friends is growing one of my ‘Park’s Whopper’ plants, started alongside the one that is in my garden, so we know that the problem isn’t just a difference in tomato varieties. Maybe my plant is in a cooler spot — with a different enough “microclimate” to allow ripening.
If your tomatoes are not ripening, and you are sure that they should be by now, consider rigging a shade cloth over your plants. Shade cloth can reduce the temperature by 5-9 degrees F, which could be all that your tomatoes need.