Rose Flowers and Buds Look Terrible in the Spring

Q. One of my roses wilts even though it’s getting watered regularly. It does get morning sun. My other roses do not do that. What’s going on?

Tough to tell because thrips are so small but this looks like Western Flower Thrips damage to roses. of the flowers and flower buds wont open and if they do they look horrible AND its in the spring....suspect Western Flower Thrips (WFT).

A. This sounds like Western flower thrips damage to the rose petals. Thrips are very tiny insects that rip and shred rose petals to smithereens. You cant see them unless you use a magnifying glass. They will spend the winter, waiting, for new growth to come out before they attack. As soon as the rose buds form, they attack the soft petals.

Thrips rip and shred soft plant tissue and “lap up” the fluids released by the rips like a dog “lapping up water from a bowl”. When these insects are in high numbers, they attack rose flowers while they are still in their buds causing them to remain closed, never to open, but damaged. They also attack nectarine fruit when they are very small causing scarring of the fruit.

Western Flower thrips also attack nectarine fruit causing scars and sap dripping in crystals from the fruit. Sometimes the damage is so bad from high numbers that the fruit is inedible.

            The usual remedy is to remove all the flowers and rid the plant of this pest land then spray with a dormant oil if it is early in the season. But Spinosad sprayshave been effective in keeping thrips at bay. It doesn’t kill them like other more toxic sprays do but is a safer alternative because Spinosad is considered a “natural” product.