|I have what appears to be scale on a jade plant. There is sticky residue with tan, pin head sized, oval shaped, crusty stuff all over the leaves and stems.
The plant is very old. I do not know how it got scale as it has been sitting in the same place for at least 9 years.
The plant is quite large so hand wiping or moving it to rinse would be impossible. If sprayed, I will have to place a large plastic bag over it as other household members have asthma. Any suggestions?
|It sounds like your jade does have scale. When it gets really bad, the leaves begin to turn yellow and sticky with honeydew, which is the "sticky stuff" you refer to. Once the plant becomes so badly infested, eradication is difficult.
Those bumps you see are actually shell-like little "houses" that the insects hide under. Only the very young (and very small) insects move about. That's why they are so difficult to contol--they spend most of their live protected by that hard coating.
As you mention, hand-wiping is usually the first suggestion. However, that's not an option for such a large plant. One thing you might try is spraying with horticultural oil. Spray to completely cover the plant, including the stem and theundersides of the leaves. The oil will suffocate the insects. Garden's Alive (ph# 812-537-8650; 5100 Schenley Pl. Lawrenceburg, IN 47025) sells a horticultural oil made from cottonseed oil. (Most others are petroleum-based.) Ask them if this product is suitable to use on houseplants. (It may cause other household memebers less difficulty than either the petroleum-based oil or other insecticides.) Follow label directions carefully.
As to how the infestation occured, more than likely the scale came in with another plant. Insects like these can even travel on clothing, pets, etc. And you may have had scale on the plant for several years, since the insects are well-camouflaged on the plant.