A sharp spray of water, from the garden hose is not necessary and if that is the water source due care is needed since the pressure from that hose can easily damage the plant more then the Aphids would, is all that is necessary to knock Aphids off any plant. Some people that know nothing about the life of Aphids might tell you that the Aphids you knocked off will just return. That is not the case although since you already have several generations of Aphids on your plant you will see more Aphids appear, and those can be knocked off with another sharp spray of water. Spraying any poison around to control Aphids will also kill off any beneficials, predators, of these wee buggers.

where in the world did you come up with the witches brew of soap and cooking oil ... are you a witch????? oiling leaves in the heat of summer.. can do more harm than any aphid will ever do ... i agree ... if the aphids are gone.. the black stuff will disappear.. if you dont kill the tree first ... when that happens.. only time will tell ... once it isnt being replaced or built up every day ... then every rain shower will reduce it ... my only suggestion ... is that you insure that there is no scale.. because they do the same thing.. and your witches brew will have no impact on them .. good luck... ken

Well, it doesn't kill them unless they happen to land on the crepe myrtle. I had a very nasty experience with di-Syston a number of years ago, and did some research which included getting material from the EPA. They said that while it has some killing effect as a systemic its major method was to release a nerve gas. It is safer to use outdoors (I was using it in the house for a serious attack of cyclamen mites in my African Violets--very effective. Gorgeous violets. Nearly killed me. May be why my husband has Parkinson's Disease, which they think may be related to pesticides.) Outdoors the gas is more dissipated. There are safer systemics now, and Neem oil or Safer soap would be I think just as effective. I suppose the Safer soap would be better to help wash off the sooty mold. I find the birds do quite a good job of eating aphids, or maybe it's the anole lizards and other helpful wildlife we have since we stopped spraying. Oh, another thing I got from the EPA publications was that it is only effective for six weeks I think it is to kill pests, but after that it breaks down into something more toxic for people and pets and they didn't, at least at that time, know how long it persisted.

Angie, Well at least manslaughter is not as serious as murder. Seriously, though, sometimes you just have to do what you have to do and I don't think y'all have harmed the crape myrtle at all. I would go ahead and cut out the dead trunk. I don't know that I'd say y'all went too far in your efforts to improve the health of your crape myrtle. It looks pretty good right now. The population of crape myrtle aphids usually peaks in late July and early August. Sometimes when the infestation is especially heavy, the lady bugs do have a hard time keeping up with all the aphids. I am glad you didn't spray anything that would hurt the lady bugs because they are incredibly beneficial. In the future, you can simply knock the apids off the plants with a sharp stream of water at high pressure. (You can use a hose nozzle or watering wand that has a high-pressure feature to do this. On my watering wand, there is a position called 'jet' that sprays a high-pressure stream of water when the want is set to that feature.) Sometimes you have to do it once or twice a day until you've done it enough to discourage them enough that they just move on. The honeydew from the aphids is not a problem in and off itself, but it can serve as a host for a black mold called sooty mold. It is unsightly and can cause defoliation when it is heavy, but the overall health of the tree is not harmed and new leaves will come out to replace any that fall off because of the sooty mold. There are several ways to deal with the aphids in the future so that you don't have a recurring issue with them every year. First, you can spray your crape myrtle with dormant oil during the dormant season in order to kill overwintering aphids. Then, in spring, check the undersides of your crape myrtle leaves in spring and spray them with insecticidal soap as soon as you notice aphids. If you can nip their population in the bud early, you usually can avoid having a major infestation of them. Having said that, since crape myrtle aphids only feed on crape myrtles, there always will be a population of them in your general area every summer, so keep checking the plants weekly and either hose off the aphids or use insecticidal soap on the undersides of the leaves. Once it is hot, though, you don't want to spray insecticidal soap on foliage because it can burn foliage of some plants in hot weather. Another alternative would be to buy and release lady bugs at the first sign of aphids on the plants in the spring. Lady bugs are kind of random and sometimes don't show up until the aphid population is huge. Sometimes I'll see them focusing on a specific pest on a specific type of plant when I'd rather have them on some other kind of plant eating its pests, but lady bugs don't take orders from humans. They don't even take requests. By buying them and releasing them on the crape myrtles when you see the aphid population appearing, you're ensuring the lady bugs are there while the population of aphids is small and more easy to wipe out. I am sure there are some broad-spectrum insecticides that would target the aphids, but I don't use broad-spectrum insecticides because they will kill all the beneficial insects too, so I am hoping you do not choose to spray with a broad-spectrum insecticide. About 97% of the insects we have in our yards and gardens are beneficial, and it would be a shame to kill them while trying to kill the 3% that are harmful. The aphid population will start dropping naturally in early to mid-August which is not that far away, so I'd just try to be patient and wait it out. I'm going to link my favorite Crape Myrtle website. It has great info in its FAQ and in its section on basic Crape Myrtle care. It also features a lot of great photos. If you're a lover of Crape Myrtles and you're ever traveling down to Dallas or points southward during Crape Myrtle season, it is well worth your while to visit McKinney for an hour or two just to see the incredible array of crape myrtles grown there. Whenever we are near McKinney in crape myrtle season, I make up an excuse to get off the highway and stop there just so we can enjoy the crape myrtles that are planted simply all over the place in McKinney. Sometimes when a plant has been topped (and this will sound drastic, but the CMs can survive it), the best way to restore its shape is to cut it back to the ground while it is dormant in winter or early spring. Then it will grow back in the shape that is natural for it. I did that with the 30-year-old crape myrtle on our property in Fort Worth because it appeared it had been topped repeatedly before we bought our house there. It regrew beautifully and the only pruning I ever had to do after that was just to remove the dead seedheads, damaged branches, branches that rubbed on one another, etc. I agree with your father-in-law that there's not much you can do to a crape myrtle that will permanently harm it. They are incredibly resilient plants. They fall in a category of great landscape plants that won't die and that you cannot kill easily (if at all). Well, extreme and exceptional drought did kill some crape myrtles in 2011, but I assume that is because they were not watered or not watered enough. Dawn Here is a link that might be useful: Crape Myrtle Trails