Garden Detective: Compost's great for lawn
We're beginning to see a sticky, white, cottonlike substance on the leaves of our aloe plant and are wondering what causes it and how it can be eliminated. The plant is watered about every other week. I've provided a photo of the plant for your inspection.
-- Richard Wong,
I'm happy to help, Richard. It looks like your aloe is under a mealybug or aphid attack. The insects excrete a sticky substance called honeydew, which is what you're seeing all over your plant. It's important to control, not only because it's detrimental to your plant, but because sooty mold grows upon the honeydew and could soon spread to nearby furniture, walls, drapery, etc. Plus, it attracts ants.
Examine the undersides of leaves and you'll notice tiny specks. Those are the intruders. Apply insecticidal soap, which is available at most retail garden centers, to the underside of leaves according to package directions. You should repeat this weekly until they're all gone. It will take time.
Individually dabbing each insect with an alcohol-soaked cotton swab also can be helpful, if not practical for large infestations. Just be sure to test a small part of the plant first to determine whether it will tolerate the alcohol. If you find the insects are stubborn, it's best to ditch the plant and start over with another.
I live in the town of Oyster Bay, and they are giving away free compost at the Bethpage site. I was wondering if it is a good idea to top-dress my lawn with it.
-- Bruce Poulos,
Top-dressing with a thin layer of compost is among the best things you can do! Over time the compost will improve the quality of the soil, and healthy soil means a healthy lawn. Compost helps sandy soil retain more moisture, helps clay to drain better, aids roots and contributes valuable nutrients.
I was wondering when the best time to plant dahlia bulbs is, now that it is spring. I took them out of the ground last fall, and they have been in a cool dry place in our basement. Also, when is the best time to put the first rose fertilizer down?
-- Kerrie Huser, Mount Sinai
Plant your dahlias outside around Memorial Day. That will ensure the danger of frost has passed. You should fertilize roses with 5-10-5 or 10-10-10 when there's 3-4 inches of new growth in early spring. Apply about 3/4 cup around the perimeter of each bush, but don't let the fertilizer come into contact with the plant. Scratch it in, and then water it thoroughly.
Last July you wrote a column on cottony maple leaf scale recommending oil spray. Several tree services I contacted recommend an insecticide such as MERIT applied at the base of the tree, what is your opinion?
-- William Butler,
Your first line of attack should be spring dormant oil applied right now (recommended application window is late March to early April.) Read the package for instructions and follow them precisely.
If the scale re-emerges, apply horticultural oil at the summer rate between 802 and 1,265 growing degree days (GDD). GDD is a formulaic system used to determine precisely when different insects reach stages of maturity. Because different stages are vulnerable to different control methods, this is important to know, as applying at the wrong time would be pointless.
The Suffolk County Cornell Cooperative Extension posts updates of GDD information for different parts of Long Island and NYC on its website: ccesuffolk.org.
I loved your video on how to make your own seed pot -- thank you! I have two questions: Will the ink from the newspapers cause any damage to the seeds and/or plants, and will the ink have any harmful effects from seeping into the ground once the pot is put in the ground? I don't imagine it would, but figured it was best to ask just in case.
-- Maggie Mulroy, Hempstead
It's generally fine, Maggie, because most newspapers today, including Newsday, use soy-based inks. Just about all color inks currently used are natural, as is much of the black.
