|Over the past few months, we've noticed a sticky substance on some of the leaves of our ivy plant, as well as on the window sill it sits on. We have a few other ivy plants, none of which suffer from this same calamity. What could be causing this problem and what can we do to prevent it?
|The sap is probably leaking from wounds caused by sucking insects. If you inspect the plant carefully you may find either aphids sucking on the tips of the plant or possibly some odd looking, darkish, flat "disks" stuck on the stems and leaves, particularly on the undersides. These latter would be scale. Both of these sucking insects can be controlled with insecticidal soap such as Safer's applied according to the label instructions. Scales may also be removed by hand by gently scraping with your fingernail and aphids can be washed off with a stream of water in the sink.|