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.
What three dwarf shrubs do you think gardeners should know about and why?
Evelyn Fink, garden center manager at The Fields on Caton Farm, Inc., Crest Hill
Yuki Cherry deutzia, Kodiak Black diervilla and Little Henry itea should have a presence in everyone’s garden. They will work well complementing taller shrubs in mass plantings and as a focal point when planted individually. All of them grow in full sun to partial shade with sizes ranging from 1½-4 feet. The itea will also grow in full shade. The unique shape and flower of each plant combined with the rich burgundy to wine-red fall color make these must-haves for plant lovers.
Mark Maradik, plant manager, Pasquesi Home & Gardens, Lake Bluff
The native Sugar Shack buttonbush (Cephalanthus occidentalis) thrives in wet heavy soils and clay. Fragrant pincushion-shaped white flowers attract pollinators. Red fruit in winter. Bobo is the best Hydrangea paniculata to date from Proven Winners. It is 2-3 feet tall and completely covered with long-lasting white flowers. The Low Scape Black Chokecherry (Aronia melanocarpa). Only 2 feet tall, tolerant of all soils; very cold tolerant. Profuse small white flowers in spring and dark purple fruit. Brilliant red/orange/ magenta fall leaves.
Jeff Schulz, owner, The Hidden Gardens, Willowbrook
My favorite dwarf shrubs have all-season interest and can be pruned to stay even smaller. Fothergillia gardenia (24-30 inches tall) is the smallest fothergillia cultivar. White flowers emerge in spring just before the leaves. Fall color is red, orange and yellow. Disease-free. Spilled Wine Weigelia (24-30 inches tall and wide) has dark purple leaves all summer if planted in full sun. Long-blooming pink flowers in spring, Deer resistant. Bobo hydrangea (30-36 inches tall and wide) produces loads of white flowers in mid- to late summer, changing to pink in fall. Flowers are held upright on strong stems and do not flop.
What is the best way to dig up, clean and store gladiolus and dahlias? What are the little white sacs on glad bulbs?
Gladiolus corms and dahlia tubers are generally dug up after the first frost or before Halloween. Cut off all the stems and foliage, let the plants dry, and shake off all the soil. Make sure each corm and tuber is firm and not rotted. Place them in a box or tray and cover with peat moss. If you know the cultivar name, tag the plant.
Store them in a dark, cool place, checking them over winter. If the dahlia tubers are shriveled, sprinkle a little water on them. Dahlias can be potted up in spring for an early start in the garden.
“The white sacs you see attached to the gladiolus corms are little bulblets. You can remove them or not. If left on the corm, they will grow larger, and may enhance the number of stems on the plant. If you remove them and plant them, it will take at least three years before they flower,” explains Joni Cotton, perennial manager, Hawthorn Gardens, Hawthorn Woods.
Do the ants on my peony flowers help buds to open, or is this an old wives’ tale? What are the extremely tiny, microscopic yellow wormy looking bugs crawling on my pink peony flowers? My peonies are beautiful, but I don’t want all these bugs.
Peony buds exude a sweet viscous sap that attracts ants. The ants do not generally affect the opening of peony buds. The old tale could have arisen because ants are occasionally seen eating large transparent drops of sap on the buds.
The tiny worms you describe are common yellow thrips, which are attracted to light-colored flowers. Thrips suck juice from buds, petals and leaves. Their triangular bodies are too small and move too fast to be hosed off the plant. A systemic insecticide should be used to prevent plant injuries.
“Peonies are such old time nostalgic favorites that people excuse their shortcomings,” says Mary Ellen Murphy, perennial plant specialist, Pesche’s Garden Center, Des Plaines. “To use the flowers indoors in cut arrangements, pick them when the buds are soft and show color, and then rinse the stems outside with a hose to remove insects.”
Late last year most of the leaves on my year-old seven-son tree (Heptacodium) turned brown, starting at the tips. It had some new growth on the tips and buds. I used a tree ring soaker hose every two weeks.
“I suspect that your watering every two weeks was not sufficient and that your tree was going into early dormancy,” says Chicagoland Gardening editor Carolyn Ulrich. “It was very dry late in the growing season and a lot of trees looked stressed.”
A rule of thumb for watering is one inch per week. Heptacodiums grow best in moist soil. You probably needed to increase the amount of time the water was on the plant and also water more frequently. Soaker hoses can run for hours.
If you want to figure out how much water your tree is receiving, use a sprinkler, if you have one, and run it on your tree until a tuna fish can has an inch of water in it, and then stop. Do this weekly, unless it rains.
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.
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.
What ratio and amounts of fertilizer would you use for a perennial bed and a vegetable garden? For growing annuals in a greenhouse, should the fertilizer be fast or slow-release, organic or inorganic?
Use 3 to 5 pounds of a 10-5-10 or 10-10-10 fertilizer per 1000 square feet in the perennial bed. Add leaves as mulch. In your vegetable bed, nutrients are important. Fertilize more heavily using a 10-10-10 fertilizer at the rate of 5 to 10 pounds per 1000 square feet.
For hanging baskets of annuals in a greenhouse, a slow-release fertilizer is best. Use a 20-10-20 liquid fertilizer following label directions. In general, organic fertilizers have a lower chemical analysis than inorganic ones, so you have to use more, according to David Tyznik, owner of Planter’s Palette, Winfield.
A healthy plant is dependent on its soil. A balanced soil is rich in beneficial microorganisms that improve the soil structure and supply necessary nutrients. Soilless potting mixes have no microorganisms. “Both organic and inorganic fertilizers work well, but those in soilless mixes need more fertilizer,” says Tyznik.
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 have lost four 12-15 foot tall white pine trees over the last year. All had the same symptoms, browning needles at the bottom that continued up to the top. Can you tell me what pest is killing the white pines? I am also losing an Austrian pine now. It is experiencing the same symptoms.
White pines in this area are very rarely troubled by disease. They are, unfortunately, highly susceptible to high pH problems, or soil alkalinity, and are utterly intolerant of salt, according to Rich Eyre of Foxwillow Pines, Woodstock. The browning needles could also indicate the plant is getting too much water or has poor drainage.If environmental problems are not the issue for your white pines, consult an expert. Betty Lockwood, Plant Information Specialist at the Chicago Botanic Garden, suggested you bring them a sample branch to check on disease and bring in an arborist for an on site visit to check your growing conditions. Or take a 12-inch sample of an affected tree to your local extension office.Austrian pine is very tolerant of environmental conditions but is prone to certain diseases—diplodia tip blight and dothistroma needle blight, both caused by a fungus. Only an arborist or a laboratory can provide an accurate diagnosis. If you bring in a 12-inch sample for diagnosis, be sure to sterilize your pruning shears with denatured alcohol after cutting the diseased wood.
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.
I have some peonies that I want to transplant but cannot plant them in their permanent place until next spring when our new house will be built. Can I dig them now and transplant them again next spring?
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?