I brought my mandevilla plant into the house to overwinter. How best can I keep it? Will it flower? Can I root pieces of it?
Mandevilla is a tropical vine requiring high light. Keep it in the sunniest part of your home. It will not flower over winter because the light intensities will not be great enough to bring on flowers and many of the leaves will fall off. It is best to keep it in a semi-dormant stage by trimming it back, withholding fertilizer and allowing it to dry out between waterings. Mandevilla is prone to aphids, white fly and mealy bugs, but don’t treat the plant preventively with an insecticide. It doesn’t work, and it also adds unnecessary chemicals to your indoor air. Treat a bug problem only if one develops. One preventive measure that does work is to give your houseplants a periodic shower or spritz them with a hand spray in the kitchen sink.
When the days are longer in early spring, begin feeding it with a 20-20-20 plant food to encourage new growth and then switch to a 20-30-20 formula. “It’s hard to propagate in winter, but in spring when your plant gets a burst of new growth, you can try to root cuttings,Ôø‡Ôø‡Ôø‡ advised Susan Izenstark, tropical specialist at Jamaican Gardens, Morton Grove.
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’m moving to a townhouse with limited direct sunlight. I would like to put a Japanese maple in a north-facing garden but don’t know if it will do well. What are the best kinds? Also, when is the best time to plant a small tree?
Japanese maples are small decorative trees which are becoming more popular as more dependable cultivars come on the market. Even so, an established tree will sometimes succumb in a severe winter. Their light requirements vary.
The trees can grow in a northeast exposure, and 6 hours of sunlight is not too much, according to Jeff Sibley, nursery manager of Red’s Garden Center, Northbrook. They need a moist, well drained, neutral soil, amended with organic matter. They can grow to 8 feet tall in a good location. He says the best planting time is right after Mother’s Day. A protected spot and plenty of moisture are critical elements for survival, even with the newer cultivars.
Sibley recommended the following cultivars of Acer palmatum var. dissectum, a cut-leaf variety, as the most graceful trees:
The foliage on our cucumber plants is starting to wither and turn yellow. They get plenty of water and I feed them regularly. What could be wrong?
“The plants may be getting too much water. They can tolerate fairly dry soil,” says Tim Norris, owner Spring Bluff Nursery, Sugar Grove. There are other possible causes for yellowing foliage as well. The cucumber beetle may have fed on the plants when they were small and transmitted bacterial wilt, which later plugs the vascular tissue. To prevent the beetle from feeding on young plants, use row covers until the plants get larger. A stressed plant is also open to attack by bacterial wilt.
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.
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.
What trends do you see in container plantings, such as type of pot, materials, sun or shade, foliage or flowers.
Brenda Williams, Sales, Pesche’s Greenhouse, Floral & Gifts, Lake Geneva, Wisc.
As our lives get busier, gardeners are looking for easy care and double duty – plants with colorful or unique leaves. Like coleus.They come in all sizes from thrillers to fillers and even a spiller called ‘Rose Lava’ that tumbles over the edge. A tall nicotiana or canna lily easily substitutes for a spike in the center of a container. A euphorbia like ‘Diamond Frost’ might look delicate but is an excellent performer whose “flowers” are actually tiny white leaves.
I also see more succulent containers. With their diversity in texture, color and form plus low maintenance, they fit well in our busy lives. They are modern and bold.
Lori Harms, owner of Countryside Flower Shop, Nursery and Garden Center in Crystal Lake.
This year we saw a huge increase in holiday greens sales, selling over 100 more than the year before. Spruce tips were in short supply so we used multiple birch logs in assorted lengths to gain height for the focal point. Magnolia leaves, seeded eucalyptus, winterberry branches and juniper berries were used to highlight the containers, along with evergreen fillers. We added elegance with glittered and iced branches in natural, gold, white or red. We also created whimsical looks by adding snowman heads or larger millimeter balls with stars or hearts on sticks for splashes of color.
Tina Perkins, Manager, Winding Creek, Millbrook
We have recently seen a progression towards decorative ceramic pots for container planting. Customers use them for fairy gardens or succulents, which seem to be trending. Depending on the size of the pot, customers may use a mix of small indoor plants and succulents. Usually indoor plants can take lower light conditions or a porch location. Succulents have become more popular to use in containers as they generally require higher light conditions. Both types of plants like a lighter soil.
Last summer my neighbor told me the black spots on my peony were a blight, although my peonies bloomed nicely. What can I do about this?
Your peonies probably have a fungal disease, a common problem. The causes are wet summers with cool damp nights, too much shade, poorly drained soil, or a lack of air circulation. While your neighbor diagnosed your problem as peony blight, which is caused by an air-borne botrytis fungus, the black spots indicate the more common phytophthora blight, according to Walter Schmidtke, nursery manager at Pesche’s Garden Center in DesPlaines.
Early in the spring, young emerging shoots may suddenly wilt and fall over, turn black and show masses of gray-brown botrytis spores. If nothing is done, these spores are carried to developing buds, which turn black.
Black spots on foliage, leaves turning red in summer, and black stripes on the stalk indicate phytophthora. “Plants with these conditions won’t have as much zest” said Schmidtke.
The best protection against recurrence of either blight is good sanitation. In fall, it is important to cut down and throw away all peony foliage, cutting stalks just below the surface of the ground.
If this doesn"t work and you resort to chemicals, the treatment is the same for both diseases. As soon as the shoots emerge in spring, begin spraying with Mancozeb, a copper sulphate solution, and repeat every 7-10 days until buds form, according to University of Illinois Extension. Spray the whole soil area for overwintering spores. In early summer you can spray plants with Daconil, a general purpose fungicide. Cut away any diseased foliage at once.
I received a beautiful flowering azalea plant during the holidays. I would like to continue growing it over winter. Will I be able to bring it into bloom next year?
Trying to get azaleas to flower in the home is difficult and time consuming because the light in a house is lower than that in the greenhouse where it originated. But if you would like to try to keep your plant growing, follow these directions.
To keep an azalea flowering after you get it, give it water-soluble acid fertilizer at quarter-strength. Keep it in a cool, shaded location, away from heat-releasing light bulbs or hot air vents.
After flowering, remove the withered flowers and keep the plant in a cool, sunny location. Water as needed to keep from wilting. In summer, sink the pot in the garden in a semi-shaded spot. Water and fertilize regularly. Acid fertilizers will help to maintain proper soil pH and keep the foliage from yellowing. Before July 1, shape the plant if needed. Keep the plant outdoors as long as possible in the fall. The plant may need protection from early light frosts but should be brought in before heavy frosts or freezes occur.
Once the plant is indoors, place it in a cool area, 40-50 degrees. An unheated porch, cold frame or similar area is good. Flower buds develop during the cold period. About 6-8 weeks of cold are needed for bud development. Do not fertilize during this time and only water enough to keep the plant from wilting. Buds should develop and swell. In January, move the plant into a cool sunny area, about 60 degrees. Flowering should begin in a few weeks. If temperatures are excessively high during this period, buds often develop poorly and new shoots will grow right past the buds, hiding them. Additional humidity is helpful to keep the calyx on the flower moist and easier to open.
Even if your plant doesn’t rebloom, all is not lost. Azaleas are known to be air purifiers.
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.
I start ‘Dragon Wing’ begonia from seed under grow lights. What other begonias can I use to cross-pollinate with the ‘Dragon Wing’ so I can collect my own seeds?
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.
Can I purchase multiple issues of the magazine?