What are the three best houseplants that everyone should own and why?
Bill Koch, owner, Hawthorn Gardens, Hawthorn Woods, Illinois
I tell people to go sit in Woodfield Mall and look at what’s doing well. We like to sell what will grow, what’s easy. So there’s ZZ plant (Zamioculcas zamifolia). It will survive if you go away for a 2-3 week vacation. Needs little water. Chinese evergreen (Aglaonema) is a wonderful plant. Will grow in any light; also doesn’t take much water. And pothos (Epipremnum aureum). We like to keep it simple.
Jackie Weiss, Garden Center Manager, Linton’s Enchanted Gardens, Elkhart, Indiana
Mother-in-law’s tongue (Sansevieria trifasciata) is one of the easiest plants to maintain. Find a place with dim light or low sun and forget it. The plant just needs a drink of water every 2-3 weeks.
Peace lily (Spathyphyllum). This is a phenomenal plant.Very easy to maintain. Will thrive in filtered sun but will do equally well in dim light. This plant loves moist soil.
Spider plant (Chlorophytum comosum) is a plant that keeps on giving. Very easy to take care of, it will often send out feelers with a baby spider plant attached. Just pop the baby in a pot of soil, allow roots to form and cut it free from the mother plant.
Dee Speaker, Greenhouse Manager, K & W Greenery, Janesville, Wisconsin
People think orchids are difficult to grow because they look exotic, but the Phalaenopsis orchid is easy to grow. The blooms are elegant and can last up to three months.
Spider plants (Chlorophytum comosum) adapt well to most places in your home and are one of the easiest plants there are. They are forgiving if neglected, and they also improve the air quality in your home.
FIddleleaf fig (Ficus lyrata) is a trendy plant. It’s easy to grow and adds character to a room. It can get tall but that’s what makes it blend in nicely with your décor.
Elizabeth Hoffman, Owner, West End Florist and Garden Center Evanston, Illinois
For high-light situations I like variegated Swedish ivy (Plectranthus madagascariensis). This trailing vine is so much fun with its vibrant white margin and aromatic scent. It prefers moist well-drained soil.
For medium light, I suggest mistletoe cactus (Rhipsalis pilocarpa). This is a cool trailing non-toxic succulent type plant that never likes to dry out. It is also not very sharp to the touch like other cacti. It prefer moist, well-drained soil.
For low light, I recommend snake plant (Sansevieria trifasciata). It’s very easy to care for as long as you let it slightly dry out between waterings. It’s very striking with its color and stiff upright habit.
Our Russian sage (Perovskia) is full and bountiful but will not stay upright. Is there anything we can do? Is there a way to split some off when it has outgrown its space? Should it be trimmed back in fall or spring?
The normal growing habit of Russian sage is to open in the center, according to Tina Pansic, staff horticulturist at Chalet Nursery, Wilmette, who says this is a common complaint. Russian sage must be grown in full sun and can be supported by pea stakes (willow or dogwood branches) or commercial wire stakes. A new cultivar, ‘Little Spire’ is shorter and will stay upright. Your plant can be divided by breaking up the root system with a spade as the bottom stems get woody.Wait until spring to cut the plant to the ground. Plants that are cut back in autumn suffer more winterkill. Pansic cuts her perovskia halfway down in late summer to control the spreading, and then cuts it to the ground the following spring
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 have a large variegated sedum with pink flowers that I have had for years. I noticed that it has started to send up some all-green shoots. Why is it doing this and how can I keep my plant variegated?
All variegated plants contain a combination of green cells with chlorophyll and white tissue with no chlorophyll, which produces the green and white effect. Variegated plants are genetically unstable, so sometimes the tissues revert to all-green cells and send up solid green shoots from the base of the plant. Because these shoots contain more chlorophyll than the variegated tissue, they are more vigorous. Thus they can quickly overrun a plant, according to Hortech, a developer and grower of sedums.
Cut the green shoots off at the base of the plant as soon as you see them. It is possible you have induced vigorous growth by giving the plant too much high-nitrogen fertilizer, so it would be wise not to fertilize. It sometimes helps to divide your plant and then choose the most variegated stems for a new plant. Since your sedum, a cultivar of Sedum spectabile, is such a rapid grower, it will quickly become a new clump after division. Newer named cultivars are more genetically stable and do not have this problem.
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.
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.
With all the emphasis on growing fresh vegetables, I think I should use a cold frame but I am not sure what to do or how to go about it. Any ideas?
Cold frames are simply four walls with a window or plastic sheet on top. They range from simply placing four bales of straw in a square with an old window atop them to more deluxe mini-greenhouses with aluminum frames, plastic panels and automatic vents using solar energy to open and close them automatically.
Before building a cold frame, study garden supply and greenhouse catalogs to determine your needs and how fancy you want your cold frame to be. Do you prefer a permanent installation or an easily disassembled frame?
A basic plan for building a cold frame is taught by Chicago Botanic Garden’s senior horticulturist Heather Sherwood. Create four walls from plywood or bricks. Add a transparent lid (plastic sheeting or an old window) for light to enter. Place the lid on an angle. Place the frame against a building, facing south. Make sure there is good drainage. Open the frame when it gets above 60 degrees. Rabbits don’t usually get into the box but chipmunks may squeeze in.
Cold frames are used for extending the growing season, starting plants early, for storing bonsai or protecting semi-hardy plants over winter. The soil in the frame depends on how you will use it. The frame can be set on existing soil when you are storing plants, or fill it with straw to protect bonsai. Locate it conveniently against the house near a back door for easy access, especially if you envision running out to cut some salad greens when snow is on the ground.
Use a cold frame to get a head start on the gardening season. In early spring, start flats of lettuce, radishes, parsley, pansies and other cool-weather plants in the house, and place them in the cold frame in March, depending on the weather. If you plan on planting directly into the cold frame, fill it with a seed starting soil mix and an inch of compost worked into the top 3 inches of the soil. This will help keep the soil loose and aid moisture retention. The plants will be small in the cold frame and can be grown close together. Also use the cold frame to harden off house-grown seedlings.
Don’t forget to check on your plants regularly because winter sun is strong and plants dry up easily. Use it for a head start on the gardening season.
From what I have read, hellebores are supposed to spread. I have a few I planted four years ago, and they seem to be the same as when I planted them. They are planted in a bed of vinca. Should I remove more vinca that surrounds them? I do fertilize them and protect them with a winter mulch. What else should I be doing to have more plants?
Hellebores increase slowly into clumps so have patience, counsels Chris Darbo, wholesale manager of The Natural Garden, St. Charles, and an enthusiastic hellebore grower. “I have Helleborus foetidus, which has finely cut leaves and blooms in January, and H. orientalis, the Lenten rose. Both have increased in twelve years to four times the size of the original plants, but they haven"t self sown. They are planted in a bed of sweet woodruff in a partly shady location.”
“I also have a clump of H. orientalis that was transplanted into my back yard five years ago, and it seeds all over the place. It is planted in shade with no ground cover. My theory is if the seeds can"t reach the ground, they can"t grow!” It takes three years before seedlings bloom.
According to Darbo, hellebores do not need fertilizer. She never rakes leaves from garden beds but instead lets fallen leaves act as a winter mulch. Leaf decomposition over the years has helped her soil to become more loamy.
H. niger, the Christmas rose, does not self seed as readily as H. orientalis and H. foetidus.
Note: A new strain of H.orientalis has recently reached the market. Known as the Royal Heritage strain, it includes colors and patterns never seen before in the species. Fifteen years in the making, Royal Heritage hellebores were developed by John Elsley, Director of Horticulture at Song Sparrow Farm in Avalon, Wisconsin.
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.
Besides mums, what are a few other plants you would recommend for containers for fall color?
Dwarf or miniature sunflowers add a bright, sunny pop of color to any container. Mix them with pink celosia, ornamental kale, dwarf ornamental grass and ornamental peppers for a special autumn arrangement. The kale is a great addition as the colors get brighter with colder temperatures. Ornamental pepper can also be taken in and kept as a houseplant through the winter months. Or use aster through October and plant in the garden before the soil freezes. Comes in many colors.
The rudbeckias ‘Indian Summer’, ‘Prairie Sun’ and ‘Becky Cinnamon Bicolor’ all have beautiful large flowers. Herbs and leafy vegetables like Swiss chard ‘Bright Lights’, mustard ‘Red Giant’, bronze-leaved fennel and variegated sage all add fun textures. Plectranthus ‘Mona Lavender’ combines nicely with ornamental kale and cabbage. Also plant trailing pansies like those in the ‘Cool Wave’ series at the edge of planters and hanging baskets. Another creative way to add interest to fall planters is with preserved and dried botanicals, sticks or accents.
Our favorite addition to autumn containers – hands down – is ornamental kale. As the temperatures drop, the leaf color intensifies and the plant actually becomes more attractive. We frequently pair ornamental kale with late season grasses as well as decorative gourds and squash tucked amongst the foliage to celebrate the abundance of the harvest season. Your visitors may still be enjoying your kale peeking through the early snow on Thanksgiving Day!
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?
I have a hoya houseplant that has been growing happily for eight years. It had flowers when I received it, but it hasn’t bloomed since. What am I doing wrong? Can I get it to flower?
What three dwarf shrubs do you think gardeners should know about and why?