What's That Crawling on My Ivy
Patricia Riley Hammer
Generally, there are not that many pests that invade ivy but there are an annoying few. Aphids and spider mites occur most often. Mealy bugs and scale also find ivy a delectable diet and can be harder to treat.
Aphids-are tiny round (green or black) fleshy insects that are generally found on the new tips of vigorously growing ivy shoots. They are easy to spot without a magnifying glass and often leave a sticky residue attractive to ants which attracts sooty mold.
Spider Mites-are very tiny spider-like arachnids that can be found on the underside of the leaves. These unwelcome visitors usually turn up during the summer heat. They become real pests on ivies in the house where they love the hot, dry and dark conditions. Ivies over-wintering in the house are likely targets with heated air temperatures that are comfortable for people and insects. Miniature spiderwebs lacing the plants, with thousands of very active little spiders scurrying around, is a good indication of a severe infestation. If your eyes are good enough to see them, they often appear to be red.
Mealy Bugs-are small, flat, white, oblong disk shaped critters with many legs. They take up residence where the leaf stem (petiole) meets the plant stem. Look for little nests resembling white cotton. The nest acts as a shelter for the insect and makes it more difficult to control. When the insects are in an active stage you can sometimes see them crawling on the stems. Look for the white cotton mass down in the center of the plant well protected from casual detection.
Scale-doesn't look much like an insect, but rather some prehistoric single-shelled miniature mollusk attached to your plants. Actually the insects are under the hard shell-like coverings they create for protection on the stems and leaves of the ivy. It is a safe place for their eggs as well. There is a crawling stage for this insect but most often you will find the scales only. Since they are camouflaged and aren't very mobile, they often go undetected for some time.
In general, I recommend inspecting your ivy plants at least weekly. Take a peek when you are watering. This is much easier if they are in pots and containers, but even the ivies in your landscape should be checked. If you are inspecting regularly, infested plants can be detected and treated before the insect population explodes.
There are some general rules to follow that will help to keep your plants in the good health and less susceptible to insect problems.
1. Keep ivy properly watered and fertilized.
2. Remove dead leaves and do not let debris collect in the pot. If they are planted into the ground, you may want to leave mulch and leaf litter but be sure to immediately remove any stems or sections that look unhealthy or rotted.
3. Make sure the ivies are in the best possible location. They need good air circulation and sufficient light. Ivies struggling in a dark damp corner become stressed and less able to resist pests. Ivies growing in too much sun without proper water and fertilizer will suffer the same stress.
Remember, any plant under stress is a target for insects and diseases. Probably the single most important weapon against insects for any plants is to keep then healthy and happy.
Even the best gardeners encounters insects from time to time. Before you reach for the harsh chemicals there are some safer things you can try.
First of all, try removing the insects mechanically. I know that no one is going to sit down and try to pick off aphids or spider mites one by one, so try a vigorous shower of cold water. Generally, you can wash away many of the insects with clear water. Try giving your ivies a shower once a week when the weather is really hot or conditions in the house are hot and dry. Spider mites particularly hate cold water. Remember, mites live on the underside of the leaves so make sure you are getting the spray up under the leaf. Cold showers are a good preventative practice. Caution: Do not give your ivies repeated showers if they are in an area where the air circulation is not adequate and the soil remains wet for a long time. The roots will rot.
A soapy water bath is another good preventative method that works. Add a few drops of any liquid dish detergent in a tub of cool water. Turn your potted plants up-side-down and swish them around until all leaf surfaces are covered with soapy water. You shouldn't need to dunk the pot, just the plant. I recommend a soapy water bath weekly for potted ivy. It will not only keep the plant fresh and clean but will probably remove insects before they become too numerous. However, I know that for many a weekly bath for their house plants is too much to ask. Do it as often as you can. It will save you time and money and disappointment in the future.
When you find an infestation of one of the above mentioned insects, start the soapy bath immediately! Give your plant a soapy bath every three to five days for at least five treatments. The reproductive cycle for some insects is very short. Bathing the plants at short intervals will destroy the insect eggs as they hatch.
If you are treating a small area outdoors, try a few drops in a sprayer bottle. There is no real need to rinse off the soap. If treating a larger area you might consider a commercial insecticide soap which won't require so many repeat treatments. These products can be found in most good garden centers.
Mealy Bugs and Scale may not be as easy to treat with soapy water. There are some other methods to use for these pests on your potted ivies or ivy topiary. Try going after then with cotton swab sticks and rubbing alcohol. It is tedious and time consuming but it is the best way to destroy these nuisances. If you are keeping a close watch on your plants it is easy to treat before the insects become too numerous.
There are certainly commercial insecticides on the market that will kill these insects in a heartbeat, but they are not always as safe. Sometimes the problem may be great enough to require a more lethal treatment. Before resorting to these methods try soapy water but if you find yourself losing the war, read the insecticide labels carefully and decide if this is the right thing for you, your family and pets. Do not use these chemicals in your home.
Often these chemicals require non-handling for several days. Isolate treated plants and make sure they are labeled with a treatment date to remind you they have been treated and when it is safe to bring them back into your home. Sometimes if the infestation is extremely heavy, it is better to actually toss the plant and buy an new one!