1 / 4

You can prune out and dispose of mossy rose galls, but they actually don't affect the health of your rose bush.

Courtesy Meredith Seaver, USU Extension

2 / 4

Mossy rose galls are most common on stems and leaves but can appear on any part of a rose bush.

Courtesy Meredith Seaver, USU Extension

3 / 4

Cracking on tomato fruits can result from inconsistent watering, but some tomato varieties are simply more prone to the problem than others.

Courtesy Meredith Seaver, USU Extension

4 / 4

Good, healthy, leafy growth early in the summer will provide tomato fruits with some protection from sunscald, which causes thickened yellow tissue during intensely sunny afternoons.

Courtesy Meredith Seaver, USU Extension

❮ ❯

We just discovered this spiky, red, spherical growth on our roses. It is green inside when cut open. We have never seen this before. The bushes are probably 40 years old and growing in a strip between two driveways. We have removed the involved stems and discarded them. Do you have any idea what it is and what to do about it?

It looks like your roses may have been hosting some mossy rose gall wasps, also known as cynipid wasps. These tiny wasps are harmless, unless you’re a rose bush or an oak tree. Cynipid wasps use rose bushes like yours to complete their lifecycle. The female wasps insert eggs into leaves or stems (or, in the case of your bushes, rose buds) and feeding by the developing larvae causes spiky, mossy-looking galls to form. The galls are called mossy rose galls. They were most common on wild or rugosa roses in the past, but it’s not unusual now to find them on our domestic garden roses, too.

The mossy rose galls on a rose bush look green at first but will eventually turn red. The larvae will stay inside the galls where they’re protected from predators, parasites and the elements and are surrounded by an abundant food source until the following spring, when they’ll pupate and emerge as adults. If you cut open one of the galls now in the summer, you’ll find that it’s a little woody on the inside, and you may see a few to a few dozen small chambers with a grub-like larva in each chamber. Galls also protect the cynipid larvae from insecticidal sprays, so there’s no need for gardeners to apply insecticides hoping to make the galls “go away.”

The galls you see won’t affect the general health of affected rose bushes, but they can weaken individual infested canes, so you did the right thing by pruning out the damage instead of leaving the canes to break accidentally. A clean pruning cut now is always better than a ragged break later. Sometimes, heavy gall formation will kill a rose cane above the galls, but most galls are just a cosmetic issue.

Because mossy rose galls don’t affect the general health of a rose bush, they don’t need any special treatment beyond cleaning up fallen leaves and pruning out any galls you may have overlooked earlier in the season. You can leave the rest of your regular rose pruning until early the following spring.

My tomato plants do very well. They become huge. Do I need to pinch them back so they will focus on the fruit rather than the plant? The second question is that I have tomatoes that split at the top toward the end of the season. Is that a watering issue?

Don’t do a hard prune now on your tomatoes as that can lead to other problems. You can pinch back the ends of the vines if the plants are outgrowing their supports, but don’t prune off leaves along the vines as removing too much foliage will be counterproductive. The sugars for tomato development and ripening are produced by the leaves. Leafy growth also protects the fruits from direct sun and sunscald.

Too much nitrogen pushes green growth at the expense of flowering (fruit). If you have been fertilizing, discontinue that to encourage your tomato plants to focus on flowering and fruit development.

Tomato cracking is usually a combination of genetics (variety selection) and inconsistent watering. During dry spells, the tomato skins “toughen up.” Then when watering resumes, the tomato fruits can expand faster than the skins can, causing cracking or splitting. Gardeners commonly see this problem if we’ve had rainy weather in the late summer. You can’t do much about the weather, but you can make sure your own watering habits aren’t contributing to the problem.

Deep, regular (but not frequent) watering will reduce cracking problems, but some tomato varieties are simply more prone to the problem than others.