Spider mites are common garden pests that enjoy a broad palette of plants, including roses. They feed on the sap in plant tissues with piercing mouthparts, causing damage at various stages of development.

The tiny insects are hard to spot with the naked eye, but their telltale fine webbing gives them away. It can appear on leaves, stems, buds, and blooms.

The best defense against spider mites and other sap-feeding pests is optimal cultural conditions. Healthy roses show the most resistance and least susceptibility to pest damage. But pest problems happen, and roses are prone to several. When it comes to spider mites on roses, there are a couple of primary treatment options and a few ways to stave them off.

About Spider Mites

Spider mites are identifiable by their webs.

Spider mites are eight-legged insects that are often yellow, red, or brown. They multiply rapidly and cause a dull look to leaf surfaces. Two-spotted spider mites are among the most common, but there are numerous species in the Tetranychus genus.

The minute sap-feeding pests congregate on the undersides of leaves. Colonies gather along leaf veins and mid-ribs underneath. In high numbers, they’ll move to leaf surfaces. The females lay eggs on the leaf underside, and the larvae quickly feed on sap and tissues. Adults feed and produce the tight webs.

How to Get Rid of Spider Mites on Roses

Spider mites reproduce quickly, so it’s important to tackle them early.

The surest sign of spider mites is webbing on leaves, stems, and buds, but there are other tells (and not all species create webs). Look for stippled leaves in yellow to bronze, possible bleaching, and a stiff texture. In severe cases, you may see accompanying leaf drop.

Rubbing a leaf between your fingers yields a rusty residue with spider mites. Be sure to check the undersides of leaves for webbing or the insects themselves, more visible with a 10X magnifying glass.

Keep Roses Well-Watered

Water consistently to prevent stress that attracts spider mites on roses.

Spider mites flock to heat and drought-stressed roses. The pests occur most often in warm, dry, and dusty situations, and roses that experience drought stress during dry spells are most susceptible.

To prevent spider mites on roses, aim for consistent watering with supplemental irrigation during hot, dry, rainless weeks. Moisture fluctuations further weaken the rose, making it more likely to experience stress from pest damage.

On average, roses need one to two inches of water per week, which is the equivalent of two to three gallons of water per rose. During summer heat and dry spells, increase water amounts to as much as five gallons (two to three inches of water weekly) and increase watering frequency.

Water deeply and regularly rather than shallowly and frequently. The flowering shrubs benefit from a good, steady soaking to promote extensive roots and moisten the surrounding soil. Deep watering promotes deeper, far-reaching roots that support resiliency during variable conditions like cold and hot extremes.

With roses, overwatering is often an issue as we aim to keep the soil evenly moist. Their roots don’t thrive in overly saturated situations and become unable to support upper growth. Susceptibility to pests, fungal, and bacterial diseases increases with prolonged moisture and dampness. With overwatering, leaves turn yellow and become soft and spongy before dropping.

The Value of Mulch

A layer of mulch traps moisture in the soil.

A two- to three-inch layer of mulch year-round helps retain moisture between watering sessions. It also regulates soil temperature, suppresses weeds, and prevents fungal spores from splashing up onto the plants when watering. Mulch brings the added benefit of soil nutrition as it decomposes.

Keep mulch off the stems of actively growing roses. Leaf mulch, leaf mold, weed-free straw, compost, bark, and aged wood chips are good options. 

Hose Spray Treatment

Blast spider mites off roses with a spray of water.

If pest scouting leads to a sap-sucking insect like spider mites on roses, an easy deterrent is a blast with the hose. To displace the insects during their active feeding and reproducing season, spray leaves and stems with a steady stream of water. Make sure to reach the undersides of leaves to impact the greatest numbers. 

The hose spray treatment separates the piercing mouthparts from the body of the mite and works well to displace the insects. It also rinses dust off the foliage and minimizes their ideal conditions.

Since roses are susceptible to fungal diseases fostered by damp conditions, water early in the day so foliage dries in the sun and breeze. Spray as needed or once weekly during the summer. Keep it up through late summer, when high heat and dry spells are likely.

Chemical Controls

Use chemical controls as a last resort.

If you notice extensive damage or high populations, horticultural soaps and oils like neem offer effective treatments. You may need more than one round if some numbers remain after an initial treatment. Miticides, too, target the pests. Spray the underside of leaves in addition to the surfaces.

These treatments affect a broad range of insects, including pollinators and beneficial predators. Eliminating predatory insects can spike spider mite populations. To avoid impacting other insects, follow application directions and apply the treatment an hour before sunrise or sunset, when there’s less buzzing activity.

Don’t use the soaps or oils in drought-stressed specimens or in high heat above 90°F (32°C). Use the hose spray method until temperatures moderate.

Adjust Fertilizer Schedules

Feeding at the wrong time can cause stress.

Nutrient-rich soils and an occasional boost with fertilizer provide a healthy base for robust growth and flowering. An excess of nitrogen, though, promotes quick production of weak, leafy stems. Overfertilizing also inhibits budding and flowering as energy goes into stem and foliage production.

When it comes to pests, sap-feeding insects thrive with nitrogen and carbohydrate-rich tissues. The flushing growth draws pests like spider mites to roses and promotes reproduction.

Plan to boost nutrition in the spring and regularly during the growing season with a balanced, specialized rose formula. Seaweed and alfalfa extracts are low-grade organic options for ongoing support.

If the shrub is heat or drought-stressed, skip fertilizing until the weather moderates. Stop fertilizing by late summer as active growth slows and the rose prepares to enter winter dormancy. Resources shift by late season to sustaining sturdy roots rather than growing and flowering.

Pruning

Prune affected areas to encourage healthy growth.

Healthy roses benefit from regular pruning of crossing, diseased, and declining canes, as well as suckering offshoots. Pruning improves air circulation around leaves and stems and reduces the spread of diseases through pest injury or rubbing wounds. It directs moisture and nutrient resources to healthy canes to improve overall resistance and vigor.

To eliminate spider mites on roses and limit further damage, prune away affected parts during extensive outbreaks as is feasible. Clip away damaged leaves and stems to a healthy portion of the stem above a leaf node. 

Debris Cleanup

Dispose of affected debris to prevent spread.

Female spider mites cozy into leaf litter and the undersides of leaves to overwinter. To limit numbers, clean up rose beds at season’s end. Sweep dropped leaves and blooms throughout the year to stave off underlying pests and diseases.

As with spider mites, pathogens overwinter in dropped rose debris and lie dormant until the active warm season. For roses and their easy transmission of common diseases like black spot, garden cleanup is vital.

Dispose of rose debris away from the garden and compost pile to prevent harboring spores and pests that later spread with the amendment. Bag up debris to throw away or burn it.

Add Companion Plants

Use companion plants to limit pest issues.

To naturally manage spider mite populations, pairing roses with companions can attract beneficial predators. Ladybugs, lacewings, and predatory mites feed on spider mites. Planting a diversity of plants boosts the food web and creates a more balanced garden system.