Unusual, slimy growths on cedar identified
Q: I've attached a picture of a probable fungus growing on our cedar trees. It's like Jell-O, slimy, smells like fish when touched, is bright orange and about 2 inches in width. Do you know what it is, if it will spread to other trees and is there a cure? — Kathy Scroch, Lidgerwood, N.D.
A: The odd-looking growths are the spore-producing bodies of a fungal disease called cedar apple rust. Cedars are also commonly known as junipers.
Cedar apple rust is an interesting disease, in that it requires the presence of both apple trees and juniper trees or shrubs to complete its life cycle. The orange fruiting bodies form on junipers and release spores that infect apple and crabapple trees. Infected apple leaves develop circular, yellow-orange spots, and often drop prematurely. Fruit can develop discolored or deformed spots. Junipers are rarely harmed significantly, but the effects on apple trees have greater impact.
Although spores can travel miles, locating junipers and apples farther apart than several hundred yards might reduce infection. Hand-pruning of fruiting bodies as soon as they form on junipers can help. The University of Minnesota suggests spraying apple trees preventatively with fungicides having active ingredients sulfur, copper or myclobutanil, or selecting apples that have some resistance, including Fireside, Freedom and Liberty, which should be winter-hardy in zone 4.
Q: We live in a condo building that has a 25-year-old dogwood hedge. How often should it be trimmed, and what is the best time? It's been trimmed a couple times the past few years. — Marilyn Sorum, Fargo.
A: Pruning of dogwood shrubs can be grouped into two categories. If the dogwood is healthy and pleasant-looking, then a light trimming to shape the shrub or limit the height can be done in early spring, or lightly in early summer.
But if the dogwood is overgrown, leggy, and crowded with old, dead, woody branches, then a total rejuvenation is in order. In early spring before leaf-out, cut the entire shrub down to 6 inches above ground level. It will regrow better than ever, and vigorous branches will have better winter coloration. Dogwoods are often best rejuvenated every 10 years or less to maintain health.
Q: Using the herbicide Curtail, I sprayed some thistles that were next to my rhubarb plants. When can I resume picking my rhubarb for eating? — R.B., Grand Forks, N.D.
A: Curtail is an herbicide used to kill broadleaf weeds, and so will also damage or kill desirable broadleaf (non-grassy) plants that it contacts, including rhubarb. Curtail's label says to carefully avoid spray drift onto desirable plants, since even a small amount can be harmful. It also mentions that Curtail can travel through the soil.
So theoretically the rhubarb should be safe to eat after spraying thistles close by, because the spray shouldn't have been applied in a way that would contact the rhubarb. If label directions were followed, no herbicide residue would be present on the rhubarb.
But if you aren't sure whether the herbicide drifted onto the rhubarb or moved through the soil, it would be wise not to eat any. If spray contacted the rhubarb, it will likely soon show symptoms including curled leaves, twisted stalks and deformed growth. Herbicide labels are necessarily detailed and often long, but the requirement to follow them is a law that protects.
If you have a gardening or lawn care question, email Don Kinzler at ForumGrowingTogether@hotmail.com. All questions will be answered, and those with broad appeal may be published, so please include your name, city and state for appropriate advice.