MSU Extension Service
Home Grown is an educational,
entertaining, question-answer column seen weekly in "News from
the Genesee MSUE Office," a weekly newsletter for Genesee
County Master Gardeners. Special thanks to the Genesee, Oakland and
Livingston county MSU Extension offices for providing this service.
01-13-05 Fungus gnats; deer protection
01-19-05 After cutting down trees: to
chip or not to chip? Also: starting seeds indoors for spring
01-27-05 Excessive plant growth in ponds;
problem trees and/or problem sites
02-11-05 Diplodia Tip Blight on Pine
trees; caring for African violets
02-14-05 Caring for Ficus in winter;
indoor pests: larder beetles
02-14-05 bonus! Fertilizer for gardens -
designer vs "regular"; why gardenias don't like our
02-21-05 vole damage in lawns & woody
plants; how to root cacti and succulents
03-04-05 tree-climbing vines; hibernating
03-08-05 deer pests in the landscape;
grain moths in kitchens
03-15-05 ants in the kitchen;
mythological apple trees
04-07-05 spring care of ornamental
grasses; little beetle in basements
04-13-05 Preventing crabgrass; flies on
04-18-05 Buying perennials in boxes; care
of perennials in early spring
05-20-05 Dogs and lawns; winter injury on
05-27-05 Sawfly larvae on Scotch Pine
trees; rabbit-eaten Burning Bushes
06-07-05A Dead spots in the lawn; grow
your own maple field?
06-07-05B Insects on your mint
plants; don't till the rose garden!
This week's HomeGrown
HOME GROWN 304
I have lots of garden phlox in my flowerbeds. The lower leaves are yellowing or browning and it appears to be working its way up the plants. When I look at the bottom of the leaves, there appears to be some tiny stuff that I canít see. What do I do? Could this be a virus?
No viruses, no alien attacks, no anthrax; itís just those pesky little spider mites. Spider mites are small, have eight legs and enjoy sucking the life out of a number of plants. Many that are being found feeding now are light green with two small black spots on their backs. Consider them the tiny vampire bats of the plant world. As they siphon off the chlorophyll, there are tiny yellow spots. These soon coalesce into yellow areas. Then the leaf turns brown and dries up. When phlox loose leaves and eventually attempt to replace them, this can have a negative impact on summer or fall flowering. Theyíve expended too much energy in leaf making. If you find spider mites, now is the time to kick them off the island. There are several possible treatments. Since they are not insects, but technically arachnids, insect sprays donít work very well. If you have insecticides, look on the label for spider mites. Insecticidal soap, bought, not made, is very effective. It is necessary to spray the bottom of the leaves, where they are feeding. They can also be knocked off the plant with a steady stream of water. This is probably one of the least effective methods. Keep in mind that no product kills eggs. Treat the plants once a week for several weeks to make sure that any newly hatched spider mites meet a quick demise. Mark the date you saw your first spider mites on the calendar. Next year, begin looking a week or so earlier and start scouting for your favorite friends.
My lawn has some strange looking grass in it this year. It is a light green and all of it has seed heads. Half the lawn looks like a small wheat field. I have no idea what this plant is but I want it out.
You and at least half the county with lawns feel the same way. You are looking at Poa annua, or annual bluegrass. This is grass has an apple green color and has some resemblance to its rich cousin, bluegrass. Consider this the Joe Dirt of the grass world. This grass does very well with cool, moist weather and often forms extensive patches. It tolerates all mowing heights from cutting short or letting it grow long. Since it is a grass, like the rest of your lawn, there isnít any magic product to cull it from the herd. In the plant killer department, there are three choices. There are products that are called nonselective. They kill green and growing anything. There are broad-leaf weed killers that kill broad-leafed plants but leave the grass. Thatís what you usually find in lawn herbicides. Then there are herbicides that are grass killers and leave broad-leafed plants alone. There arenít any homeowner products for separating grasses, killing the bad and leaving the good. Just to cheer you up, hot dry weather can cause the Poa annua to die and you can be looking at unsightly bare areas intermingled with your regular grasses. There are bezillions of new seeds from the Poa annua so you might want to attempt to reseed some of the bare areas early this fall, like mid August with real lawn grass.
Gretchen Voyle, MSU Extension-Livingston County Horticulture