Hi, everyone, The fungus that causes dogwood anthracnose spreads from sick trees in the spring, via spores carried by splashing rain, and possibly insects, birds and people. It is probably not such a good idea to go dig up 'free' dogwoods in the woods anymore. It's a 'new' disease, not clearly identified until the early 1990s.
To keep your dogwoods from getting it, first of all keep them healthy. Plant them in soil well supplied with organic matter, ideally good 'living' compost. Be sure to mulch around the base (but not right next to the trunk, remember mulch like a bagel, not like a volcano), no deeper than 3-4 in (less than 10 cm). Water regularly during dry periods using drip or watering at the base, not overhead sprinking. Shady wet conditions favor the disease, so try to keep the trees 'open' to light and air even if they are under bigger trees. Fertilize with compost, stay away from high nitrogen fertilizers. Be careful to keep mowers and trimmers away from the trees (all trees). Keep leaves raked up in the fall. Remove dead limbs before the disease reaches the trunk and - especially - any brown leaves that hang on the tree through winter. My suggestion is to keep any such material from sick plants out of your home or garden compost pile. Though tree health is the most important defense, you can choose to apply a fungicide in the spring at bud break, continuing for about a month. Organic options include Bordeaux mix (see a recipe, it's copper sulfate solution, essentially) or one of the commercial organic 'biological' interference agents which offer a mix of natural fungicidal agents and bacteria. Compost teas might also work, as a spray. Non-organic fungicide options include mancozeb, among others - call coop extension for chemical advice, but stay away from systemics anywhere near food crops. You can pick resistant types of dogwood, but not all dogwoods are the same. Kousa dogwood (Cornus kousa) is a Korean dogwood. It's a pretty tree, but not at all the same as American (flowering) dogwood (Cornus florida). Kousas look to me almost like a doublefile viburnum when they flower, at least a month after local dogwoods down here in zone 7. There are some kousa x florida crosses, such as the 'Stellar' hybrids. More interesting to me are American dogwood varieties that have been developed from resistant plants, such as 'Appalachian Spring'. As Denise says, other native trees make good choices for gardens. Redbuds (Cercis canadiensus, I think)certainly are nice. One favorite of mine is 'Forest Pansy', with purplish leaves in the spring, like an ornamental plum tree. Good luck, So far, I've seen no sign of the disease locally, but I know people who've seen it. It's not popular. Don Boekelheide Charlotte NC __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus Powerful. Affordable. Sign up now. http://mailplus.yahoo.com ______________________________________________________ The American Community Gardening Association listserve is only one of ACGA's services to community gardeners. To learn more about the ACGA and to find out how to join, please go to http://www.communitygarden.org To post an e-mail to the list: [EMAIL PROTECTED] To subscribe, unsubscribe or change your subscription: https://secure.mallorn.com/mailman/listinfo/community_garden
