My three spider plants are infested with scale. Is there a “natural way” (no chemicals) to get rid of it?
Scale insects are parasitic and can be tricky to control once they have established themselves on one’s houseplants. By the time that they are noticed, they probably have developed a hard waxy shell and are exuding a sticky substance (honeydew) which one may notice on the floor or other surfaces near the plant. At this stage, scale will be more difficult to treat. However, for a brief time after they have hatched, they are able to move around until they attach their sucking mouth parts to the plant.
If they are detected in this ‘crawling’ stage, spraying the plant with insecticidal soap will likely be effective. Insecticidal soap is a popular organic control for many plant pests; however, this treatment will need to be repeated until the scale are eradicated. Scale lurks under the soil of infested plants and will continue to affect the plant.
Once scale have formed the hard shells, insecticidal soap will probably not be effective. If the infestation is small, one might be able to remove the affected parts (leaves) from the plant. Another solution is to try to scrape off the scale and then apply the insecticidal soap. Otherwise, the use of a horticultural oil will be necessary; repeat treatments as necessary.
If the plant is covered with scale, it might be prudent to get rid of the plant. Treating scale can be very challenging. In any event, isolate the plant to prevent the spread of the scale to other plants while you are treating it.