Trim off and destroy yellowed tulip leaves to help control tulip fire, a fungal disease causing flowers to die prematurely. Remove heavily infected plants. Heavy infestations may require insecticide treatments starting in mid-June. Check and prune out scale infestations on euonymus and pachysandra. Infested branches can be pruned out in May or treated in early June, when the small, young crawler stage appears.
Crawlers are visible with a handlens and look like tiny scales.
Handpick and destroy leafminer-infested foliage on holly. Look for leaves with zigzag or blotchy patterns from the insect mines. American, inkberry and winterberry hollies have miners specific to each. Check underneath rose leaves with holes to find small, yellow-green aptly named roseslugs. Handpick or treat if needed.