There are many ways to prevent and treat rose diseases and pests.

The first step is to be careful when you buy the rose. Pick disease-resistant roses such as Earthkind roses. (These roses were tested by Texas A&M’s horticultural department.) Whatever rose you select, inspect it thoroughly. If you bring home a rose with pests or a fungal disease, these problems can spread to your other roses, so be careful. Learn the signs of rose-mosaic virus and avoid roses with these symptoms. (The most obvious symptom of Rose Mosaic Virus is yellow lines on the leaves, often in a wavy or fern-like pattern.)

Use care when pruning: sterilize your tools between plants. Remove spent leaves from the ground, because many diseases can re-infect your rose after over-wintering in dead leaves. Use preventative products such as natural repellents, dormant oil sprays, and soapy water sprays with baking soda. Consider releasing Preying Mantises and Ladybugs in your garden. (But if you release beneficial insects, then spray with a broad-spectrum insect killer, you’ve just wasted your money!)

For Individual Diseases and Pests:

Rose Mosaic Virus: This will probably not spread to your other roses, (since roses are infected by grafting with a diseased rose) but a rose infected with RMV will never thrive. Be careful to sterilize your tools after pruning a diseased rose. You might want to replace a rose infected with RMV.

Blackspot, Powdery Mildew, Rust, and other Fungal Diseases: Make sure there is “breathing room” around your roses. Good air circulation can prevent many Fungal diseases. Remove leaves that have fallen on the ground-many spores hide here and can re-infect your rose. Treat infected roses with Potassium bicarbonate products such as Remedy, or with Neem oil products. Or try a homemade spray: mix baking soda with soapy water (the soap helps it “stick” to the plant.)

Rose canker: This shows up as discolored spots on canes. Use a dormant-oil spray after pruning to prevent this. Unfortunately, the only way to treat this is by removing the infected cane, although you can try to just cut it off far below the canker.

Aphids: Horticultural oil and soap are a great deterrent. Spraying with a soapy water works well, too. To make a Soapy Water spray: mix non-scented, non-antibacterial dish soap with water. Let dandelions grow as a “trap-crop”–aphids would rather eat a dandelion than a rose any day.

Thrips: If you have a problem with these insects, then you might want to grow darker roses. For those of you with the double hedge of Iceburg roses lining your driveway, I have a couple tips. Repellents work better on thrips than poisons, because by the time they die, they’ve already ruined your blooms. Good bug repellents for roses include garlic or pepper sprays, or cedar-based products such as Cedarcide.

Japanese Beetles: The best way to get rid of them is hand-picking. Or put out beer or fermented fruit-juice in a steep-sided container and let them drown. Applying repellent might be worth your time also. Try garlic or pepper sprays, or cedar-based products. Treat the soil for grubs.

Cane Borers: Cut off the cane below the borer. Seal up the cut, and seal all cuts made whenever you prune roses if you have a problem with this type of pest.

Scale, Spider mites, Leaf Rollers, Rose Chafers, and other pests: Use horticultural oil, a soapy-water spray, or a general insect-repellent to discourage these pests.