Chapman, Douglas J. 1981. Late flowering trees provide mid-summer color, interest. Weeds, Trees & Turf 20(9): 26-27.
Trees which flower early to mid-summer can be particularly important in the landscape. When looking for diversity with excitement, yet low maintenance, yellowwood, goldenrain tree, Kousa dogwood, and goldenchain tree should be high on the list. These trees integrate well into mass plantings. They all seem relatively drought tolerant, having few or no insect and disease problems. Although their fall color varies, the uniqueness of early to mid-sumer blooms makes these truly exciting additions to the landscape. Although borderline hardy in central and northern Michigan, they should be considered somewhat commonplace from Detroit all the way south to the Washington, D.C. area.
Lambe, Robert C. and G.H. Lacy. 1982. Crown gall. Am. Nurseryman 155(3): 113-114.
Crown gall is a serious disease that can severely affect ornamentals. Numerous woody ornamentals are affected, including cypress, euonymus, forsythia, hibiscus, lilac, flowering peach, privet, roses, viburnum, and willow. Galls range from a fraction of an inch to several inches in diameter. Crown gall was first associated with the bacterium Agrobacterium tumefaciens in 1907. Only in the past decade was it discovered that the gall or tumor-inducing principle is part of a separate genetic entity, a plasmid, that is itself parasitic within the bacterium. The “pathogenic” bacterium, then, is just a vehicle for transmitting the disease-causing organism to the plants. After the bacterium attaches to plant wounds and multiplies briefly among parenchymatous cells, the tumor-inducing principle moves into the plant and is maintained with the host’s genetic material. Because the bacterium is not necessary for tumor development, many galls become “aseptic” or free of A. tumefaciens. Strict sanitation is necessary to prevent spreading pathogenic bacteria.
- © 1982, International Society of Arboriculture. All rights reserved.
