Question

Sargent Crabapple Tree   I have a very young Sargent Crabapple that I planted this spring.  I have noticed that it now has white cotton-like stuff on the underside of some of the branches.  Some of it washes off when I water it, but there is more the next day.  Can you tell me what it is?

I live in Wendell, NC - 15 miles east of Raleigh, NC.

Thank you.

Answer
Sounds like cottony aphids, an insect.
Check and see if there is movement when you touch the cottony stuff. If so these are insects. There also should be some stick liquid on the leaves caused by the insect sucking the plant juices. IF so.
Chemical Control - Contact Insecticides Numerous contact insecticides are registered for aphid control. Since aphids are often placed under considerable pesticide pressure in field crops and greenhouses, they may be resistant to certain categories of insecticides. Therefore, if you do not obtain reasonable control, consider rotation to another insecticide. Contact insecticides currently registered for aphid control include: acephate (Orthene),  bifenthrin (Talstar), chlorpyrifos (Dursban), diazinon,  malathion, nicotine sulfate, pyrethrum, rotenone, resmethrin, and tetramethrin + sumithrin.
These insects are easily killed I would recommend the Orthene as a good product.