Dogwood anthracnose

I was looking at systemic fungicides to treat dogwood anthracnose. Would it be safe and effective to use a fungicide intended for lawns instead of trees (spectricide immunox) that says it treats anthracnose, on my dogwood?

Reply to
Daveman750
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According to the University of Maryland, "Fungicide should be applied preventively at budbreak and every 10-14 days until leaves are fully open. Repeat during cool, rainy spells and when foliage starts to turn red in fall. Use fungicides containing chlorothalonil, mancozeb, or benomyl."

Benomyl is a systemic. Chlorothalonil is the active ingredient in most garden fungicides. I think bordeaux mixture should also work if you don't mind the baby blue residue.

Best regards, Bob

Reply to
zxcvbob

It's sad what it does to dogwoods... I have a lovely old one in my front yard that is quite sick from it, I will be looking for the resistant variety when we are forced to replace this lovely old friend. It will take so many years for whatever we buy to even begin to compare to the one I have now, they grow so sloooowww. Colleen Zone 5 CT

Reply to
GrampysGurl

It will be the same 7-10 day spray interval. All "systemic" means in this instance is that the leaf surface absorbs a tiny bit of the fungicide instead of it just coating the surface, not that it's carried throughout the plant's vascular system. And the absorbed amount still has the same half life. Spraying trees is a PIA. Better to buy resistant cultivars. If the tree is large and has a lot of personal significance, and arborist can come inject a fungcide into the cambrium, but that is a every 6 week interval proceedure, and frankly, I'm not convinced that the wounds to the tree aren't invitations to invasions of other kinds of insects and disease. And, BTW, if a fungicide doesn't say it treats it, it usually does a poor job, and it's actually a violation of federal law to use a pesticide in a way not listed on the label. Immunox doesn't work very well on anthracnose or cercospora on roses, wheras chlorothalonil does, but with risk of phytotoxicity, increased during the warm months. But, anthracnose prefers cool wet spring/fall weather and usually just goes away during the heat of summer, so you could probably get by with only spraying during spring and fall with an registered fungicide.

Reply to
Sunflower

Dogwood anthracnose is a systemic and progressive fungal problem. It doesn't just "go away" with warmer, dryer weather - it is just not as likely to be as obvious with any new foliage appearing to be free of problems. But the pathogen remains present, but perhaps non-active during drier weather, within the tree's internal tissues. IMO (and one that is supported by others), treating with a fungicide only delays the inevitable.

Cultural controls will help prolong the tree's viability as well. Clean up and destroy any debris (fallen leaves, etc.) which may harbor spores of the fungus, avoid pruning (which dogwoods resent and which can spread the infection) other than obviously deadwood, fertilize sparingly in early to mid-fall (which will provide nutrients to the root system but not encourage vulnerable lush growth) and keep well watered during summer's heat.

Dogwood anthracnose is a widespread and serious problem for certain species across the country and Sunflower's advice is sound - it may be best to consider replacing soon with a resistant species or hybrid. In my experience, despite one's best intentions and expensive treatment regimens, the progress of this disease is only slowed but seldom, if ever, controlled and the ultimate outcome is pretty much a given.

pam - gardengal

Reply to
Pam - gardengal

When the tree does die, the wood is strong and lovely. Maybe you can make something from it.

Best regards, Bob

Reply to
zxcvbob

I have a forest full of dogwoods and probably half of them have anthracnose. I had a state forrester look at them and he said they would eventually die no matter what I did; the best thing to do was cut them up for firewood; and NEVER transplant wild dogwoods into town

- I'd only be spreading the disease.

Bob S.

Reply to
Bob S.

If you are going to spray your dogwoods I would reccommend mixing mancozeb and propiconazole(fertilome systemic fungicide). I take care of the spraying at the nursery I work for and use the agrucultural strength stuff that has the same active ingredients. Follow the directions exactly and they should be fine. You will have to spray in spring and late fall for it to be effective.

Toad

Reply to
Marley1372

This is why all experts recommend getting dogwoods from a nursery rather than transplanting wild ones. When you have bunches & bunches of wild ones, spraying is just not feasable since dead leaves, twigs, and bark which carry the disease cannot be controlled. Any cut, scrape, or broken twig allows anthracnose to enter the tree.

Bob S.

Reply to
Bob S.

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