Cut Flower Updates: June 20, 2025

Welcome to this season's cut flower updates! Here, you'll find information about what Extension Educators are observing on cut flower farms around Pennsylvania. We'll discuss pest, disease, and production topics useful to growers as the season progresses. If you haven't signed up for our email list, you can manage your communication preferences and select "Commercial Cut Flower" as one of your preferred Areas of Interest.

After a slow, cool start to spring, temperatures are rising across the state, and crop growth is ramping up. As plants push out new growth, aphids are feasting on succulent stems, in some cases causing leaf curling or distortion. These piercing-sucking insects can usually be found clustered on branch tips and on the undersides of leaves. Aphid feeding this week was observed on many woody shrubs used for cut stems.

Sticky secretions of honeydew can be found where feeding is heavy. Growers can often see the white cast skins of aphids that have molted alongside feeding adults, as well as some winged adults. The presence of winged adults often indicates a high population density, as females develop wings and fly to new plants when food sources become overcrowded.

Some natural predators, including lady beetle larvae and adults, were observed hunting for aphids. In a typical season, natural predators can help tremendously to keep the aphid population in check in outdoor growing environments.

Heavy aphid feeding can reduce the vigor and growth rate of plants, and their presence, honeydew, and sooty mold feeding on the honeydew can decrease the harvestability of cut flower crops if present close to harvest.

Aphids can sometimes be dislodged from leaves and stems with a strong stream of water, though this may not be a feasible option in large production areas. In ecologically diverse landscapes where broad-spectrum insecticides are used infrequently, naturally occurring predators like lady beetles, lacewings, syrphid flies, parasitic wasps, and minute pirate bugs often knock the aphid population back to a manageable level before significant crop damage occurs. Insecticidal soaps and horticultural oils are effective, but can cause phytotoxicity in some cases, so the product label should always be consulted before application.

It remains to be seen whether this will be a bad year for aphids on flower crops. Regular scouting can help identify problems early, assess crop damage, and decide on the need for control measures.

Are you experiencing a pest, disease, or weed issue on your cut flower farm? Email Margaret Pickoff at mfp5667@psu.edu. We're always looking for new issues to explore in our weekly post.

Photos: Margaret Pickoff