Needles Looking a Little Thin?
Most narrow-leaf evergreens will shed their old needles, some more often than others. In the fall each year, you can anticipate that white pine, Virginia pine, red pine etc. will develop yellowing needles that fall and accumulate on the ground beneath the branches. Evergreens such as arborvitae, chamaecyparis, Leyland cypress and white cedar trees will also shed their needles but at a much slower rate.
Most pine trees will retain their old needles for 18 months or so depending on species and amount of new growth. The new growth shades out the older needles, causing them to turn yellow and drop. If you prune away the new growth in mid summer, then the pine trees will retain their old needles through a second growing season.
Arborvitae retain their old needles, or scales, until the new growth completely shades the old foliage. The older needles turn brown and remain attached to the branches. New gardeners often become upset when they look into the inner stems of their arborvitae and see large sections of dead-brown foliage inside the plant. This is a normal process, and there is nothing that you can do about it. However, if you see needles that have emerged since spring turn brown and drop, you have problems.
The hurricane and tropical storms this summer helped to develop a disease called needle cast in many narrow-leaf evergreens such as junipers, fir and some spruce trees. If you can predict that this disease is going to occur, you can prevent it from becoming established by spraying with a fungicide such as copper sulfate. However, most people don’t realize that the trees are in trouble until they are losing most of their foliage. If the tree had already developed strong vegetative buds along its branches, it will survive, looking ugly, until next spring. But if needle cast disease occurred before the tree had a chance to develop strong vegetative buds along its branches, the tree will most likely not survive and grow next spring.
Don’t give up the tree for dead if there are pointed buds lining the branches. The heavy rains came after the buds for next year’s growth had developed, so many trees with needle cast disease have strong, well-developed vegetative buds and will resume normal growth next spring.
Flies in the Compost
Q: I read your Oct. 13 article on wetting compost with keen interest. I have some kind of what, for lack of knowledge and recognition, I call small maggots. When I turn over the pile, which is wet, they are prolific indeed. The pile is warm and it does decompose significantly from week to week, even though I add lawn clippings regularly. The maggots don’t seem to bother the process, and as far as I’ve noticed they don’t hatch. If they do hatch, they don’t stick around for very long.
My question: Is this a harmful process? Should I abandon the pile and start anew? I add eggshells, vegetables, fruit rinds and peelings as they accumulate. The pile otherwise seems fairly ordinary. Thanks for any advice. Enjoy your column very much.
–Tom Lyons, Edgewater
A: The maggots that you see are mostly fly maggots that do no harm. I have them in my pile, but they disappear as soon as the worms take over. I add egg shells and vegetable and fruit trimmings to my compost almost daily. When I turn the pile, the maggots disappear because of the heat generated in decomposition.