Chokecherries seem to be prone to black knot. Depending on your climate, it could be a problem to you. I've got chokecherries that grow among pie cherries and plums in a bit of a jungle. Many of the older chokecherries have some cankers, and on occasion it will show up on a cherry. I don't recall seeing the plums showing any signs. But--I am in a very dry climate where moisture to aid in the spread of the disease is fairly uncommon. Since it has never bothered me, I've never done anything about it--didn't even know what it was until fairly recently. So, depending on your climate and the specific susceptibility of your trees, you may or may not have a problem. Still, if it is present in your area, you may want to take preventive measures. Otherwise, you could risk an infection, remove it as soon as you find it, then start treatments going forwards. Kocide is used as a foliar spray as a bacterial disease preventive/inhibitor on some crops, though it may be used at a lighter rate than when you dormant spray. Kocide doesn't cure an infection, so you must apply it before the infection takes hold to inhibit the initial infection or slow its spread. This means it is usually applied earlier in the growing season or just before the time the tree is most susceptible to infection. Nude Gardener: Many of the names listed are the trade names you would purchase the product under. Often they are capitalized. The chemical names are usually not capitalized, and sometimes, though not always, sound more "chemical-like". Many of these chemicals are sold in the garden sections of your favorite local stores and the big box stores, plus at garden centers/nurseries. If in doubt, do an internet search on the term and you'll find out pretty quickly whether you have a trade name or a chemical name, and you can quickly get the other name. Also read the label to see what crops and uses it is registered for. Unlike medicines, if the use you have planned is not labeled, it is illegal to use it for that crop/purpose. The blue stuff is copper sulphate, which is the active ingredient in Kocide. The crystals are not as easy to dissolve in water, but they do work in drains to kill tree roots. Kocide is formulated so that you can easily get the proper concentration of copper sulphate in water and to ease application. Some of these products are not sold for the home market. Sometimes they present a greater safety risk, so they will not be sold to homeowners who are not expected to have any knowledge in proper use and safety with pesticides (I'm not saying home users don't use them properly, but nothing says a home user HAS to know how to use the product, so mis-use is more likely). Others will not be sold to the homeowner because the companies deem the market to be too small, or the EPA is trying to limit exposure potential to the general public. Commercial formulations will be packaged in larger quantities and concentrations for use by commercial growers. However, if the product is labeled for the crop you have and will use it on, it is perfectly legal to purchase it from a farm supply. The main drawback is that it will generally come in packages that will treat a number of acres, which means a 20 year supply for the home gardener. If you are purchasing a commercial grower's product, you may need a private applicator's license, depending on your state's laws. If you do, the cooperative extension service in many states handles the training and/or testing for these licenses, so you can check with them to get certification and a license. The private applicator's license where I am is pretty common. It takes about a half day of classroom instruction on the safe use of pesticides, calculating application rates, reading labels, etc.

Nancy, the Bordeaux mix should only be used while the tree is still dormant - before bud break. It can be phytotoxic, which is why it's recommended to be used before the tree is in leaf. And you never want to spray during the flowering period when pollinators are present. Other than the Bordeaux mix, this is going to be a difficult problem to control just restricting yourself to organics......sad, but true:-( Cultural controls and good garden sanitation are critical and MUST be used together with any fungicides, organic or not - sprays alone will not do the trick. Part of the diffculty is that the fungal spores germinate and spread when the weather is warm, generally some time after bud break and one can't determine the degree of infection until the following year when the galls begin forming, so some sort of spray program is advised. Pruning out problem areas is most often advised but won't help a wit if the infection has progressed to major limbs or the trunk. You just need to remove the tree at that point. If I were in this situation, I might try using Neem oil for spraying any time after the trees emerge from dormancy and when the temperatures are close to 55F or above. If possible, spray when no threat of rain is present for at least 24 hours and don't spray when pollinators are present - Neem can harm them as well as any chemical. I'd repeat applications every 10 days to two weeks through shuck split (when the tepals fall off to expose any emerging fruit). Otherwise, there are very few fungicides that are registered for control of black knot (and most you wouldn't want to or can't use anyway) but if you use something registered for brown rot and follow a similar spray schedule, you should be OK.

Dawn was sort of saying that tongue-in-cheek, but since nematodes are worst in sandy soil, I figured adding clay wouldn't hurt. However, adding tons (literally tons!) or organic matter would be better. You also can buy beneficial nematodes that eat root knot nematodes. They're available from places like Planet Naural and Arbico and other similar firms. Planting Elbon rye during the cool season is the most effective organic method of controlling them that I know of. If I had nematodes (you can have them in sandy clay that's low in organic matter), I'd take a multipronged approach. I'd add all the organic matter I could every year and I'd probably add a litle clay and I'd release beneficial nematodes too. If you can't find Clandosan, you can make your own by grinding down crab and shrimp shells, if you can find them. The last time we talked about Clandosan, I think we found out that it was very, very expensive. You might try e-mailing OSU or your county agriculture extension agent or your county master gardeners group and see if they know of a source for Clandosan.

Dale, In general, garlic is considered a poor host for nematodes (as is corn), so often it is recommended that you plant garlic in an area where you have a consistent root knot neamtode problem. So, in general, garlic ought to do passably well in areas infested with RKNs. However, if you have a very heavy infestation of RKNs, even garlic can be stunted and less productive. You won't know if the RKNs in your soil are at a high enough level to affect your garlic harvest until you try growing garlic there and can see what results you get. I doubt you have enough nematodes to affect garlic, but I could be wrong since I don't have nematodes here and my experience with them is from long-ago in Texas. If you have dealt with RKNS before, then you already know all the practices that will help. Unfortunately, one of the best techniques is to grow Elbon cereal rye in the cool season, but you can't do that if you're growing garlic. If it were me, I'd work to change the soil over time in the same way that you have been. I'd add as much manure and compost as possible, as well as sugar or molasses to stimulate microbial action. Although chitosan's cost can be prohibitive when trying to rehab a large garden, it might be worth it to you to purchase some and add it to your soil where you intend to plant the garlic. Or, if you have access via seafood restaurants to shellfish shells, you could compost your own to get the same effect. There is evidence that tilling in pine bark fines about a month before planting can help reduce damage from RKNs. If it were my garden, I'll try the solution in the attached link, but I haven't tried it and can't vouch for its effectiveness. As with all plant diseases or pests, resistance is only resistance and not immunity. I doubt total immunity exists in any variety of a RKN host plant although, of course, in non-host plants like carrots and lettuce, I'd think you'd have total immunity since they don't host the little RKN brats. Good luck, Dawn Here is a link that might be useful: The Gardens Alive Solution to RKNs