Extension News

Ask the ISU Extension Garden Experts: Tree Galls, Squash Bugs and Peppers

Note to media editors: Got gardening questions? Call the Hortline at (515) 294-3108, Monday-Friday from 10 a.m. to noon and 1 to 4:30 p.m., or e-mail us at hortline@iastate.edu. For more gardening information, visit us at Yard and Garden Online, http://www.yardandgarden.extension.iastate.edu


There are light green growths on the upper leaf surface of my silver maple. What are they and what effect will they have on the tree?

The light green growths are probably a type of gall. Galls are abnormal plant growths caused by insects, mites or other organisms.

Heavy infestations of galls may disfigure a tree’s foliage and cause premature leaf drop. However, leaf galls normally do not cause serious harm to healthy, well established trees. Nothing can be done once the galls have formed. Preventative applications of insecticides or miticides (in future years) usually are not practical nor necessary.

How can I control squash bugs?

Squash bugs can be serious pests of summer and winter squash. Squash bugs have piercing-sucking mouthparts. Heavy feeding causes entire leaves to wilt, turn brown and die. Several methods can be used to control squash bugs in the garden. Brick red egg masses on the undersides of leaves and squash bug adults can be removed by hand. Adults also can be trapped under boards or shingles placed under the plants. Turn the objects over daily and collect and destroy the hiding squash bugs. Small, immature squash bugs (nymphs) can be controlled with insecticides, such as Sevin, permethrin or insecticidal soap. Sprays are generally more effective than dusts. If the squash plants are blooming, spray in the evening after the honey bees have quit foraging for the day. In fall, remove and destroy garden plant debris to deprive squash bugs of overwintering sites.

When can I plant peppers in my garden?

Peppers are a warm-season crop. Plant peppers in the garden after the danger of frost is past. In central Iowa, peppers can be planted in mid-May. Gardeners in southern Iowa can plant one week earlier, while those in northern counties should wait an extra week. The last practical date for planting peppers is approximately June 20.


Contacts :

Richard Jauron, Horticulture, (515) 294-1871, rjauron@iastate.edu 

Del Marks, Extension Communications and External Relations, (515) 294-9807, delmarks@iastate.edu