Identifying & Preventing Spider Mite Damage on Roses

Spider mite damage on ‘Piñata’ rose

Sometimes bad things happen to good roses. Spider mites, Tetranychus, can spell doom for a rose if not caught and dealt with quickly. The best form of control is prevention, which I learned almost too late, but if you do find that your roses are under attack, there are things you can do.

Spider Mites feed on plant cells leaving behind leaves that look dry, yellow-bronze, dusty and stippled.

Spider mites are a type of arachnid, and there are hundreds of different kinds, but it’s the two-spotted spider mite or Tetranychus urticae that attacked my roses just recently. These little jerks are so tiny you can barely see them, but the damage they can do in such a short period of time is astounding. They feed on the plant cells of a rose sucking the very life out of them and leaving behind leaves that look burned, yellow-bronze, dusty and stippled. In severe infestations you may also see webbing, especially on the underside and corners of the leaves. If you are experiencing dry, hot conditions, that is prime time for a spider mite infestation and their numbers can increase exponentially so be extra vigilant. The best method of control is early intervention. During hot, dry spells, increase the humidity by watering your roses well and hosing off the leaves to remove any buildup of dust or dirt. Remember to do this in the morning to give your roses time to dry off. (We don’t want to get rid of mites only to be then afflicted by fungus!) Keep the area around your roses clean and free of debris and try not to use pesticides that would kill off the mites natural enemies.

Remove and discard leaves and canes that are the most heavily damaged as I did here with my ‘Piñata’ rose

OK, so lets say you’re like me and you missed the warning signs and found yourself under a full-fledged attack. When I saw that almost all of my roses were heavily afflicted I felt like the sky was falling and went into panic mode, especially when I read reports online from other gardeners saying at this stage my roses were going to be a goner, but it really did turn out ok. Here’s what I did: First, I hosed down every rose using the highest setting of pressure I could to really blast the heck out of those mites and knock them off the leaves. (Make sure you get the underside and don’t be afraid to lose some leaves to the pressure of the water.) Next, I removed and discarded (in the garbage, not in the compost pile) as much of the damaged and infested areas of the rose without completely compromising it’s ability to regrow. Last, I used diluted Neem oil to spray all parts of the rose, canes and all parts of the leaves letting it heavily drip into the soil, too. A couple of applications of Neem (about 1 week apart) and regular hosing down during that dry spell did the trick, and since then, my roses are on the way to recovery. Have you ever experienced a spider mite attack? Do you have any organic methods of control that worked for you?

Although my ‘Piñata’ rose lost about half of it’s volume, it is thankfully on it’s way to a full recovery!