Q: Attached are photos of two weeping caraganas, purchased from two different local nurseries. Both are called the same, but they look very different. One is starting to show yellowing of leaves. Is this caused by iron chlorosis like the maples in your recent article? Do you know why the two weeping caraganas look different? - Jerry Luebke, Fargo.
A: There are two different types of weeping caragana. Caragana arborescens "Pendula" has slightly larger leaflets, and is usually called simply weeping caragana. Caragana arborescens "Walker" has very small, fine, fern-like foliage and is called Walker weeping caragana. Both types would sprawl along the ground if left to their own natural growth habit, but to form a neat, small-scale feature, they're grafted onto 4-feet-high trunks that let them "weep" and cascade downward.
The caragana genus is extremely winter-hardy and well-adapted to our alkaline soils. In fact, many of the early pioneers planted caragana as part of shelterbelts and as trimmed hedges around farmyards. Because they're well-suited to our soil, iron deficiency chlorosis would be unusual in caraganas. Instead, the yellowing might be caused by overly plentiful moisture in your landscape. Caragana tolerate dry conditions very well, and can develop yellowing leaves if conditions stay moist. The rock and fabric in your landscape might be keeping the caragana wetter than they prefer, although other types of shrubs are doing well. Remove rock and fabric in a circle around the caragana, leaving open soil that will dry quicker. A thin layer of wood mulch could be added.
Q: We have several ash trees with dead leaves on them - just a few on some, and quite a lot on others. I didn't think the emerald ash borer had gotten this far north. Is this the type of disease they spread or is it a symptom of something else? - Paul Overby, Wolford, N.D.
A: The dead leaves are likely caused by a common leaf disease called ash anthracnose. It's a fungus disease that has affected ash trees region-wide for decades. Some years it's worse than others, and some years it doesn't appear, depending greatly on weather conditions. Ash anthracnose rarely harms a tree, although a percentage of leaves can yellow and drop. Control sprays are rarely recommended.
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Emerald ash borer, the insect that has caused widespread damage to ash in eastern states hasn't been reported in North or South Dakota, according to the latest June 1 insect progression map from the U.S. Department of Agriculture. In Minnesota, emerald ash borers have been sighted in the Twin Cities area and Duluth.
Q: I have a split-leaf philodendron house plant that is doing quite well. Just recently it starting putting out stem-like light brown things that look like roots. Am I supposed to cut them off or put the ends back into the soil? - Linda Stone, Walcott, N.D.
A: Split-leaf philodendron is a native of tropical jungles. The brown root-like structures growing from the stems are called aerial roots. In the jungle, these roots can absorb moisture and nutrients from the humid air. They develop naturally on philodendrons as they age, often indicating they're happy in the environment they're in. They can be left intact, or cut off at the point of origin. There's no need to get them into dirt since they're adapted to above-ground living, but you can if you'd like. If the air is less-humid than a jungle, aerial roots sometimes wither and dry up, and can be removed then.
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.
