Question: My roses have looked terrible the last few weeks. The flowers don’t open all the way and the petals have dry, brown edges. I haven’t changed anything about the way I take care of them. What’s happening?

Answer: From your description, it sounds like your rose blossoms have been damaged by thrips. These tiny insects damage the petals while the flowers are still at the bud stage, making them difficult to control with organic sprays.

Good plant care will help your roses be more resistant to thrips:

• A systemic insecticide in the spring is effective if applied properly and can remain effective for the entire season. Read the label and follow the directions carefully.

• Deep, infrequent watering and good weed control will help your roses to be more resistant to thrips.

• Remove and discard any infested blossoms as soon as you notice damage.

• Deadheading roses is a good idea, even if you don’t have thrips.

Helpful hint: Here’s one last rose tip for this time of year — it’s time to stop fertilizing your roses if you’ve been doing it regularly throughout the summer. This will give the plants time to harden off and be ready for their winter dormancy.

Q: There is a lot of white powder on some of my squash and pumpkins and some of the leaves are falling apart. Is it too late to do something?

A: It’s common for squash and melons to start showing powdery mildew at this time of year. Our dry, hot weather is just what powdery mildew needs and many gardeners have reported seeing it in their gardens over the past few weeks.

Powdery mildew is a disorder caused by fungi. There are actually many different fungi that cause powdery mildew and the white splotches that you see on your squash are caused by different fungi than the powdery mildew you may see on your maple trees or zinnias.

Leaves that are infected by powdery mildew may not be able to produce enough carbohydrates to feed the plants and the fruits on the plants. The plants will be less vigorous and the quality of the fruit will be reduced. Severely infected leaves will turn yellow to brown and can become crispy. They make break apart in windy weather.

The first line of defense against powdery mildew is to choose varieties of squash, pumpkins and melons that are resistant to the fungi. Resistant varieties will usually become infected much more slowly that susceptible varieties. If you absolutely have to have your favorite varieties instead, there are a few things you can do.

The best way to control powdery mildew in your garden is to get in the habit of going out at least every other day looking for the first signs of infection. Check both the outer and undersides of the leaves. The sooner the signs of powdery mildew are seen, the more successful you’ll be with control treatments.

At the first signs of infection, begin treating with fungicides right away. Once the infection is severe, fungicides won’t be effective. Fungicidal treatments need to be repeated every seven to 10 days to protect the leaves. There are fungicides for organic gardeners as well as conventional gardeners. Read the label carefully, apply as directed and repeat as recommended for the number of treatments allowed.

Powdery mildew overwinters on infected plant debris, so this fall, clean out your garden completely. Remove or turn under any plant debris to reduce the number of spores that will be produced next year.

Space your squash and melons plants more widely next year to slow down the spread of infection.