We are first-time gardeners and have planted Brussels sprouts and green and red cabbage that we are trying to grow organically. There are black egg sacs and small green worms eating the leaves. Is there an organic product we can use on the cabbage?
Egg sacs can be washed off with a hose.
There are several organic methods you can use to deter cabbage worms. Lightweight polypropylene row covers, placed over a row of plants and supported by hoops, will block wind and insects while permitting light, air and rain to reach the plants. Hold down the row covers with soil, stones or bricks.
Another organic method uses pots of mint growing between cabbage plants. The mint odor is said to deter cabbage moths. Don’t let the mint take root, however; it will take over your garden. Rotenone dust is considered organic, as it leaves no poisonous residue on plants. The use of hot pepper spray is an irritant to insects and worms, but also to your skin and eyes. Bacillus thuringiensis (Bt) is a specific biological control that is fatal to cabbage worms if ingested. Note that it can be harmful to certain butterfly larvae.
I am growing my potted tropical hibiscus indoors for the winter. The leaves are starting to yellow and fall off. Should I give the plant iron and should I fertilize it? Do I cut it back, and if so, when?
Hibiscus leaves turn yellow in response to the change in environment. The older leaves fall off first. If the leaves are chronically pale yellow with green veins, the plant could be lacking iron, but in your case, it is probably the change in growing conditions that is affecting the plant. When the days get longer in February or March, prune it to shape it, or cut it down to force good bottom growth.”
“Don’t panic; the plant expresses itself dramatically,” reassures Mike Geimer, owner of Geimer Greenhouses, Long Grove. “Don’t be timid pruning it.”
Why do I have brown areas near the tips of my dwarf Japanese junipers? This has been occurring the last few years. They are supposed to be drought resistant”
“It’s hard to diagnose without seeing the plants or their location,” says Matt Warrick, sales associate in tree and shrubs at Gethsemane Garden Center, Chicago. “Your plants may be in a situation that’s too dry. With the type of drought we had this past summer, even if a plant is drought-tolerant, it would have needed supplemental watering.”
Other factors that affect junipers are poor drainage, insufficient light, fungal disease, and insufficient acidity in the soil. Any of these conditions could cause needle browning.
I am sick of slugs. Perhaps if I knew their life cycle I could get rid of them. Where do they go over winter? Where do they come from? What is the best way to get rid of them?
Slugs are gastropods belonging to the mollusk class. They have lungs and can breathe air and live one year. At nightime, to conserve moisture, they feed by biting tissue with a rasping mouth underneath their body. They move by sliding over slime secreted by a large muscular foot and constantly lose water from this slime production and evaporation.
To make matters worse, they are hermaphrodites having both male and female organs and can deposit egg-like clusters of 1/8 inch pearls in soil where they overwinter. Their growth is activated by rising soil humidity and temperature in the spring, according to Ed Valauskas, Manager of Library and Plant Information Services at the Chicago Botanic Garden.
Even if your soil is relatively slug free, they can come in from a neighbor’s yard or live in the soil of container-grown plants. If you garden in very sandy, fast draining soil, you will probably not have many of these pests, but in heavy clay soil, slugs find constant moisture that suits their life style.
Slugs feed on plants with moisture in them, especially hosta, ligularia, dahlia and begonia leaves, lettuce, strawberries and tomatoes. They hide by day and feed at night or on gray, damp days. Go outside with a flashlight after 10 p.m. and look for them under boards, rocks or pots and destroy them.
Laurie Skrzenta of Laurie’s Landscape, a Downers Grove hosta grower, keeps the hosta area dry and doesn’t water them because slugs do not live in dry locations. She depends on rainfall and maintains that hostas can exist without supplemental water. Laurie also suggested using coarse sand as a mulch. Another possibility is to sprinkle sand in the center of your dormant hostas since this is where the slugs lay their eggs.
There are many home remedies to get rid of slugs including beer, ammonia water, ice water, and yeast water. Gardener Anna Hevrdejs, Woodridge, suggests sprinkling corn meal around slug areas. Slugs like to eat it, then die. Replace it after a rain. She also claims that sweet woodruff planted around hostas restrains the slug population.
Chemical metaldehyde or methiocarb pellets are useful but they can be attractive to dogs and children. They are very toxic. Much safer is a copper strip laid around the areas to be protected, although this is not practical in an ornamental garden.
How can I get rid of voles? I think they are doing a lot of damage to my bulbs.
Voles are mice-like rodents that gnaw on roots and bulbs. They are hard to control.
There are repellents on the market that you can try—Deer Off, Moletox, and a new product named Shot Gun Repel. The latter repellent was designed specifically to protect bulbs from chipmunks, moles, voles and mice. Treat the bulbs before storing or planting. Remove old skin and soil, and then spray thoroughly until wet. Allow the bulbs to dry before storing or planting.
I applied commercial compost and hardwood mulch to an area where I am establishing a small garden. I did a few soil tests on the area and the results indicated the nitrogen was depleted. I intend to spread a bag of dried blood to rectify this problem When is the best time to apply the dried blood?
Landscape professionals are usually skeptical about results from home soil tests. They don’t always produce accurate results unless you take a large soil sample from many parts of your yard.
“Take your home soil test results with a grain of salt,” advises Tony Fulmer, manager, Chalet Nursery, Wilmette. He cautions not to become overly excited by the results. “Hard-wood mulch is used by landscapers all over the area, and I don’t see a problem with it causing nitrogen depletion.”
Apply the dried blood now. The 12% insoluble nitrogen starts working when soil temperatures rise.
I am interested in improving fall color in my yard. What shrubs turns red beside burning bush (Euonymus alatus)?
Wendy Vichitk, plant manager at Luurs Garden and Flower Shop, Hillside, recommends these shrubs for a colorful fall garden:
Low growing 2- to 3-foot Virginia sweetspire ‘Little Henry’ (Itea virginica) has red foliage and grows in both sun and shade. The foliage of the somewhat taller ‘Henry’s Garnet’ is dark red, as the name indicates.
Fothergilla ‘Mount Airy’ has blue-green leaves that turn intense yellow and orange-red in sun and half shade.
Oak leaf hydrangea (Hydrangea quercifolia) grows in shade or partial sun, with orange-red to red fall color.
The leaves of apple serviceberry (Amelanchier grandiflora) burn a bright orange red. There are several cultivars on the market to choose from.
Many viburnums have bright fall color. The easy to grow Korean spice viburnum (Viburnum carlesii) and the also fragrant V. juddii have leaves that produce a mixture of red, orange and mahogany. Arrowood viburnum (V. dentatum) and cranberry bush viburnum (V. trilobum) both exhibit typical red-purple color.
The intensity of color is affected by the weather. Warm sunny days followed by cool nights bring the highest leaf color. The health of the plant, its growing conditions, and the amount of water the plant receives also affect fall color.
Would it help to apply a starter fertilizer on a poor green lawn in December? Will it give it a head start for spring? It hasn’t been reseeded.
Some people have applied fertilizer over snow when the grass is dormant. However, it is best to fertilize in November to winterize your lawn and give it a start for spring, according to Steve Hipenbecker, assistant manager of Nature Scape, Gurnee. Use a fertilizer labeled as a “winterizer,” not a “starter.” Lawn starter products, typically high in phosphorus, are intended for newly seeded lawns. Winterizer fertilizers are typically high in potassium, which helps increase cold tolerance and disease resistance. Although advertised for fall application, winterizer fertilizer can be applied in spring as well. You can seed in spring, but early September is generally considered the best time to seed a lawn. The soil is still warm, the nights have cooled down, and dew collects on the grass each morning.
I brought a frangipani (Plumeria) back from Hawaii last April when it was just a leafless branch. It sprouted leaves and grew over summer. Now it is losing its leaves. How can I keep it growing over winter? Will it bloom?
During winter, plumerias defoliate naturally. Keep your plant somewhat dry.
” We keep it in the cactus section over winter because it really likes to dry out. It doesn’t need a lot of misting. A southwest window with bright light is the best exposure for it.” says Lourdes Espinosa, greenhouse associate, Sid’s Nursery and Greenhouse in Palos Heights.
In spring, depending on the weather, and as the days lengthen, resume watering and fertilize with a high-phosphorus liquid fertilizer every two weeks. When the night temperatures remain reliably above 50 degrees, the plumeria can be grown outside. Acclimate the plant slowly to the outdoor light by keeping it in a shady place for a week. It flowers from summer to autumn.
Plumerias can grow into a 3-foot shrub with good care. Wear gloves when pruning since the sap is toxic and irritating to the skin.
My split-leaf Japanese maple tree is 15 to 20 years old, about 7 feet high and about 10 feet wide. It is overtaking the corner of the yard. Can I trim it, and at what time of the year?
Trim your tree in late fall to early winter when the tree is dormant. Remove only one-third of the amount you want pruned each year, being careful to retain all its charm.
“Go easy on it,” says Joann Madon, horticulturist, The Growing Place, Aurora and Naperville.
After my father’s tomatoes ripen on the vine, he finds when he cuts into them that there is a hard white core that extends through the fruit.
When is the best time to cut back hydrangeas? How far do I cut them back?
I would like to start seeds under lights. When is the best time to start flower seeds? The seed packet always says to sow a number of weeks before the last frost. When is the last frost?