I have a dampish area with poor grass and moss that I would like to change to ground cover, but if I have only one plant, won’t it be boring? Can I get rid of the grass in winter or early spring?
If we have a dry winter or spring, you can smother the grass with a heavy layer of newspapers held down by bricks or stones, or use a product that will kill the grass. Use it according to the label directions. Grass roots are very persistent, so you may have to dig out the remaining roots by hand. The moss will disappear as you aerate the soil and rake in organic material.
When your area is properly prepared, you will have a large choice of low-growing groundcovers.
Kim Schroeder, perennial buyer at Wasco Nursery and Garden Center, St. Charles, suggests the following: lily of the valley (Convallaria majalis), sweet woodruff (Galium odoratum), wild ginger (Asarum canadense), or European ginger (A. europaeum), vinca (Vinca minor), Tiarella, Astilbe-the cultivar ‘Perkio’ is shorter than Astilbe chinensis ‘Pumila’ and violas such as bird’s foot viola (Viola pedata) or sweet white viola (V. blanda).
These choices are not aggressive growers like goutweed (Aegopodium), which grows anywhere and is very difficult to eradicate. You can plant free form areas with one type and another alongside it as contrast. Most of these ground covers bloom at slightly different times to give you a spring-into-summer flowering season.
Will a trumpet vine growing on a tree harm it?
Trumpet vine (Campsis radicans) is a vigorous vine which can climb to the top of a tree in one season and spreads by suckering roots. It blooms in full sun in clusters of 3-inch-long orange tubes with flaring scarlet lobes.
The vine will not harm an established tree but a young tree could be stressed.
“There may be root competition between the vine and the tree for moisture, especially if your tree needs a lot of water. However, trumpet vines can grow with less moisture. When customers claim their vine does not bloom, it is because they are watering and pampering it too much,” says Lori Harms, greenhouse manager, Countryside Nursery and Garden Center, Crystal Lake.
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?
“In this area we use May 15 as a benchmark for the last frost date, but it can be earlier or later,” says Chuck Prosek, grower at Prosek’s Greenhouse, Winfield.
If your seed packet gives you the number of days to germination, add that to the number of weeks for growth, and then count the number of weeks back from May 15. Tomatoes sown indoors generally need 6-8 weeks of growth before being set out.
Many seed packets do not include germination time. A good guess is to allow 1-2 weeks for the seeds to germinate, but if you use bottom heat, your seeds will germinate earlier and grow faster. Most seeds need warm soil of 65 to 70 degrees to germinate and grow.
When you sow seeds directly into the soil, till the upper inch of soil to loosen it for direct seed to soil contact. The outside soil temperature must be above 50 degrees for cool growing plants, and at least 65 degrees for warm season annuals, according to Prosek.
For future reference, keep a record of indoor sowing dates, germination dates, length of indoor growing period, and transplanting dates.
What is rose rosette disease? I lost two antique roses and removed a hedge of multiflora roses that were supposed to be undesirable. How bad is it?
Rose rosette disease is a plant killer of unknown origin and no known cure. It is known to plant pathologists, but unknown to most rose gardeners in this area.
The disease is believed to be caused by a virus or virus-like pathogen that has been spreading through much of the wild rose population in the Midwest, probably transmitted by a mite introduced to the U. S. to eradicate multiflora roses. It is lethal to the wild multiflora rose and potentially lethal to many rose species and cultivars.
Symptoms of rose rosette disease are highly variable, depending on the species or cultivar. Some of the more recognizable symptoms include rapid elongation of new shoots forming witches brooms, or clustering of small branches with distorted leaves of conspicuous red pigmentation and distorted flowers.
David Robson, Springfield, extension educator, horticulture with the University of Illinois, reports that it is all over our area. Mike Geimer, owner of Geimer Greenhouse, Long Grove, reports coming across RRD in a Long Grove garden. One plant in a bed of Flower Carpet roses caught his eye because of its uncharacteristic red clumping stems. He looked up the symptoms on the internet, identified it as RRD and advised immediate removal of the plant. Also important, warns Geimer: “Always sterilize pruning shears.”
Kathy Hallgren, Sycamore, is worried about the future of old roses. Two summers ago she noticed some peculiarly rampant irregular, hyper-thorny pink growth with irregular leaves on an antique Alba rose.
After researching the symptoms, Hallgren determined the irregularities were from RRD. “I dug out the plant and burned it. Once I learned that multiflora roses could be the culprit, I removed them even though they were healthy. This summer I saw it on one of my ‘William Baffin’ roses so cut it down and burned it. This disease means business,” says Hallgren.
No effective control is available for existing rose rosette disease. All cultivated roses are potentially susceptible. Be on the lookout for it. Early detection is the key to effective cultural control. If the disease is recognized early and the rose is removed, it is possible to save other roses in the garden and hopefully curb the spread of RRD.
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.
After a summer outside, my clivia has returned indoors. Last year it had only one puny flower. What treatment should I give it over winter to bring it into bloom?
A. Clivia miniata, sometimes known as Kaffir lily, a South African native, is a member of the amaryllis family. When growing clivia, it is important to observe seasonal changes. During short winter days, stop fertilizing entirely until spring, and stop watering also.
“Treat your plant like a cactus,” says Steve Butcher, tropical plant specialist at Sid’s Garden Center in Palos Hills. “You can keep it completely dry for a couple of weeks up to the point of shriveling before watering. Keep your plant in a cool place; 55 to 65 degrees is ideal, but that’s hard to achieve in many homes. It does not need a brightly lit location.”
When the days lengthen, move the plant into a brighter location and increase watering. There are no hard-and-fast rules on watering. The frequency depends on the pot size and the root mass. Use a water-soluble, high-phosphorus fertilizer every second or third watering. After you see buds, reduce fertilizer to once per month. Root bound plants flower better.
Following this regime last winter, Editor Carolyn Ulrich reported five bloom stalks on one of her plants in February. Other plants bloomed in March but one didn’t bloom until June. Clivia are considered a winter-flowering houseplant, but bloom time will vary. Be patient.
I’d like to know the secret to growing a decent-sized pumpkin for jack-o-lanterns for the grandkids and for decorating. My experience in recent years is that they get about as big as a basketball and then begin to rot. What am I doing wrong?
The longer the fruit is on the vine, the greater the chance it will rot. By September its size is apparent, and it turns orange. It is best to plant pumpkins in different soil each year or every two years, according to Sue Murdock, manager, Goebbert’s Pumpkin Farm, South Barrington.
The size and use of pumpkins is determined by the seed you buy. ‘Atlantic Giant’ produces fruits that weigh hundreds of pounds. A better choice is to grow ‘Howden’. It bears well-shaped 10 to 20-pound fruits, the perfect size for jack-o-lanterns. ‘New England Pie’ is the standard for pies with smooth, bright orange flesh. ‘Wee-B-Little’ is a miniature round pumpkin bearing 3- to 4-inch fruit useful for table decorations and suitable for tiny hands.
I thought that purple coneflowers were insect proof, but now I see some aphids at the bud and tiny flies. What is wrong?
Purple coneflower (Echinacea purpurea) is a common native perennial that grows best in sandy or well-draining soil and full sun. If you are not giving your plant these growing conditions, certain insects can attack your plants.
Aphids are sometimes visible on buds, and as sucking insects they cause stunted and deformed leaves. Spider mites are tiny insects that often multiply in hot, dry conditions. Spider mites feed on sap and cause yellowish leaves. Thrips are barely visible, tiny insects causing bud malformation.
Can I grow asparagus from seed? I saved the little red berries from my plants.
You can grow asparagus from seed. I have done so many times, but it takes three or more years for a crop, and growing from seed usually gives inferior plants. Better crops come from hybrid plants.
If the red berries from the female plant have dried over winter, there should be two or three black seeds inside. Clean them off and prepare your seed bed for planting.
Asparagus needs full sun and a sandy loam soil raked smooth. After the danger of frost is past, bury the seeds at a depth two times its diameter and keep the bed moist. In the third year you can lightly cut the pencil-thin stalks. There are often volunteers of female plants between rows you that can transplant. However, it is best to start asparagus by buying roots so you have a small crop the first year. Most varieties sold are male.
I have a cycas palm and am not sure how much direct sunlight or water it needs. It has light brown marks developing on the leaves. What is causing this, and how do I care for my plant?
Cycas palms or sago palms (Cycas revoluta) are tough house or patio plants. They are neither palms nor ferns but primitive cone-bearing relatives of conifers. A rosette of green feather-like leaves, 2 to 3 feet in height, grows from a central point at the top of a single trunk.
Cycas need bright light and should be kept relatively moist with weekly watering. However, prolonged rainy spells can cause fungal leaf spot disease.
“The shiny brown spots are probably caused by scale,” says Jeff Frohn, sales associate at Geimer Greenhouses, Long Grove. “It can be treated with fish oil, vegetable oil or an all-in-one insecticide spray,” adds Mike Geimer, owner, Geimer Greenhouses.
I keep seeing photos of interesting plants I’d like to grow, but they’re labeled zone 6 and I’m in zone 5. What can I do to successfully overwinter these marginal plants? I’d like to try them, but I don’t want to waste my money.
I have two 3-year-old rose of Sharon plants, about 20 feet apart. One blooms every year. The other plant forms about 100 buds and looks healthy, but it has not bloomed in the last two years. The buds are solidly closed and look as if they are rotting from the inside out. There does not seem to be any sign of insects on the plant. What is this problem?
What three dwarf shrubs do you think gardeners should know about and why?