Gardening Questions Answered

Winter Citrus Pests

There are small dark bumps on the twigs and branches of my citrus. Or, there is white, fluffy stuff on the twigs and leaves. The leaves are turning yellow and falling off and twigs are dying back. Why?

The small dark bumps are citrus scale (probably brown soft scale) and the white fluffy stuff is cottony cushion scale. Both are common pests on citrus. To eradicate both of these pests, spray horticultural (not dormant) oil twice, in May and June, two weeks apart when temperatures are not above 90 degrees. This should smother and kill the young scale in the crawler stage. You can also spray during the cooler season when temps are not under 32 degrees. Thoroughly drench all surfaces of the tree as well as the soil underneath. Always read the labels and follow directions carefully. When improperly applied, horticultural oils can damage trees.

Citrus Black Scale

Citrus Cottony Cushion Scale  

California Red Scale and Yellow Scale