Everyday gardener // Q&A

Struggling tomatoes, rain barrels and rootbound plants

Even though spring started in earnest in March this year, it still seems like summer is going by too fast. So, fast, in fact, my inbox has been a bit stuffed with questions. As always, I’ve replied directly to people who asked for help with various things. But here in the column I’m going to cover some of the questions that seem likely to be of interest to a lot of gardeners. By far, the questions I’m getting most are about tomatoes, so I’ll start there.

Q: My tomato plants look good and have a lot of flowers, but I’m not getting a lot of fruit this year. What’s going on?

A: It’s been too hot for tomatoes to set fruit lately. When it gets above 90 degrees, flowers on tomatoes, peppers, eggplants and other vegetables wither and drop because the pollen, which is sensitive to high heat, isn’t fertilizing them. Obviously, there’s no real way to beat the weather. But you may have better luck if, next year, you plant varieties that mature at different times so if one doesn’t fruit well others might.

Q: I’ve got tomato plants with a lot of leaves but very few flowers and tomatoes. Why is that?

A: If otherwise healthy tomato plants aren’t flowering, it’s probably because they’ve been overdosed on nitrogen. Rather than using a balanced fertilizer, which you can recognize because ratios for all three nutrients, nitrogen, phosphorous and potassium, will be the same as in 10-10-10, switch to one with a lower first number. Five is probably good. Or you can just amend your soil well with composted matter like compost and then continue to top off your tomatoes with compost all season. In the meantime, though, you’ll need to wait until the excess nitrogen gets used up, which won’t take long in a container. Heavy rains will move the process along faster.

Q: Is it true that I should cut the roots of plants before I plant them, especially if they’re rootbound?

A: Good question. This one gets debated a lot. You know you’ve got a rootbound plant when you tip it out of its container and matted roots are more prevalent than soil. Wrapped in a tight ball, the roots usually circle the bottom of the plant because they’ve had no place else to go and the soil around them has broken down. It is best to separate the roots as best you can before planting, and that probably means cutting out some of the most matted parts. Being rootbound puts a lot of stress on growing plants because they lack the nutrients they need to thrive. If you don’t try to correct the situation at planting time, those plants are likely to be stunted. They may even fail to grow much at all or even die. The debate comes in over whether to slice the roots on the sides of container-grown plants whether they are rootbound or not. Studies have indicated that the practice doesn’t help but many gardeners think it does. So you might want to try experimenting with that yourself.

Q: What does it mean when a plant is labeled as “disease resistant?”

A: Contrary to what the name suggests, plants labeled “disease resistant” are not actually immune to a particular disease or diseases. Instead, they are able to tolerate some diseases and overcome the harmful effects of the fungi, bacteria or other pathogen that might be attacking it. While no plant is resistant to all diseases, seeking out disease resistant varieties is a good idea.

Q: Is it OK to water vegetables with water from my rain barrel?

A: People disagree on this, but most say no. The reason for this is that runoff from asphalt shingles, which most roofs are covered with, contain bacteria and other contaminants. Plus, no one seems to know whether plastic rain barrels sitting in the summer heat leach chemicals into the water contained inside. To be safe, don’t use water from rain barrels on anything edible. Save if for your lawn and other plants.

Q: I saw a lot of beautiful magnolia trees this year and I would like to plant one. Is it too late to do that?

A: Yes. Normally, fall is the best time to plant trees because the soil is warm and it isn’t waterlogged like it can be in the spring. But for reasons that are not completely understood, some trees don’t do well when they’re planted in the fall. Magnolia is one of those, so I recommend waiting until spring.

Q: I always plant bulbs in the fall, but I hate the look of the dying foliage in the spring. Is there anything I can plant near bulbs that will help hide those ugly yellow leaves?

A: It doesn’t seem fair, really, that bulbs finish their display with a mass of unsightly, yellowing foliage. But allowing that foliage to yellow and whither means you’re giving the bulbs the time they need to nourish themselves for next year. Cutting it off might make your garden look better, but it certainly shortens the life of bulbs.

Meleah Maynard is a Master Gardener and freelance writer. If you’ve got a gardening question you’d like her to address in her column, you can email it to [email protected]