Summers in Phoenix are always extremely hot and dry, creating an ideal environment for spider mites. Each year, spider mites and thrips become our main adversaries in the intense heat. To combat spider mites in your garden, it’s essential to maintain the health of our plants by properly watering and nourishing our roses.
Roses that are stressed are particularly vulnerable to attack. Our lack of summer rain, and the heat we’ve endured, require us to give special attention to our roses. Potted roses are especially susceptible to spider mites because they dry out quickly. Water your potted roses daily. Deep watering of your roses is recommended.
Spider Mites Are Under Your Leaves
Spider mites live in colonies, mainly on the under surfaces of leaves; a single colony may contain hundreds of critters. The webbing a spider mite produces distinguishes it from aphids and thrips, which also infest the bottom of leaves.
Spider mites feed and breed on the underside of rose leaves. The two-spotted spider mite (Tetranychus urticae) has two dark spots on the sides of its body and can be yellow, orange, or green. Their rasping mouthpart pierces the epidermis of a leaf, causing them to appear yellow or bronze. During severe infestations webbing over blooms, stems, and leaves are visible. If left untreated, defoliation can occur, especially on the lower leaves. Extreme infestation and continued drought conditions can cause the entire plant to die.
It’s common to have mites in an outdoor garden, as they are a natural part of the environment. Minor damage shouldn’t worry most gardeners. But if the mite population grows large enough to cause visible harm to the leaves, it could lead to complete defoliation.
Spider mites reproduce rapidly in hot, dusty weather and constitute a significant problem in Arizona from June through September. A new generation can be generated in less than a week if the temperature and food supplies are favorable.
Spray Your Plants 2 or 3 Times Weekly
One of your summer goals should always be to control the spider mite population. You’ve already invested in your roses; ensuring their ongoing health is a small expense. Keeping your roses healthy doesn’t have to be a big expense, if you water and feed them regularly. Creating a healthy environment for your rose plants can deter pests from making them their home, so keep the dust down, plant ground cover, use mulch, and irrigate consistently. Don’t forget to spray your plants with water, making sure to cover the undersides of the leaves at least two or three times a week.
Spider mites have many natural enemies. When undisturbed by pesticide sprays, the predators limit the mites’ numbers in many gardens. Creating favorable conditions for predatory mites, minute pirate bugs, big-eyed bugs, and lacewing larvae is crucial for the best results.
Insecticides are not recommended for home gardeners because spider mites often overwhelm a garden once the natural enemies are killed. It also appears that insecticides stimulate mite reproduction. There have been studies that show spider mites can reproduce faster when exposed to carbaryl (Sevin).
To avoid encouraging rapid mite population growth, I’ve started using a Dramm water wand with a “Fogg-It” nozzle to tackle the mites. I found mine on Amazon. Don’t be too cautious when spraying your leaves. The “Fogg-It” nozzle delivers a powerful stream of water that effectively dislodges mites and thrips from the foliage. While I may not completely eradicate them, I feel more at ease knowing I’m doing my part to hinder their breeding cycle. Consistency is key, as mites often seek refuge in unsprayed areas.
