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 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.
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.
We all seem to plant the basic herbs like basil, rosemary and parsley. What suggestions can you offer for more exotic herbs that I could add to my garden to spice things up both for cooking and adding interest/beauty to my landscape?
Ron Peterson, head grower, Milaegers Garden Center, Racine, Wisc.
I think lemon grass (Cymbopogon citratus) would be a good candidate for landscape interest and culinary use; it is even reported to have more mosquito control attributes than citronella. It is a warm season annual grass that grows quickly and is used in teas and Thai cooking to add a lemony flavor without the acidity of lemon juice. Stevia is a natural sweetener option for those trying to avoid added sugar. There is also a mint called Berries and Cream which merges peppermint with berry flavors for a unique twist on the traditional mint options.
Lisa Hilgenberg, horticulturist, Chicago Botanic Garden, Glencoe
Golden lemon thyme (Thymus x citriodorus) adds good citrus flavor to dishes and tea. The 8-inch tall cultivar ‘Aureus’ makes a good edging paired with Salvia officinalis ‘Icterina’. The chartreuse ‘Lime’ shines in dark garden corners.
Red shiso (Perilla frutescens) has frilly garnet red leaves, edible flowers and a spicy cinnamon/clover flavor. Papalo (Porophyllum ruderale) has a taste between arugula and cilantro. Plant once cilantro bolts to seed. Steely blue foliage up to 5 feet tall.
Joe Heidgen, co-owner, Shady Hill Gardens, Elburn
A plant that is often included with the popular herbs that gardeners know at Shady Hill is the scented geranium. It doesn’t look anything like a garden geranium, but it has a wide range of fragrances, as well as varying leaf shapes and colors. The fragrances may be lemon, rose, pine, ginger, lime, balsam or apple. It can be used in cooking and also in potpourri and sachets. Some scented geraniums are upright, some cascading, but all are unique and quite easy to grow. They are ideal for planters.
Kevin DeBoer, manager, Big John’s Farm Market, Chicago Heights
Onion or garlic chives can be grown and cut for use in potatoes and eggs. We also have five different types of mint that can be grown and used for mojito, flavoring water and teas. Some varieties such as pineapple mint are attractive and add beauty to the garden. Thymes such as English and lemon can be used in pasta and in marinades for grilling. A good marinade for meat can be made from thyme, rosemary, sage, Italian olive oil and pepper.
I have two 20-year-old pine trees whose needles are turning brown on the west side of the plants. On the east side I have a compost pile.
I live in the St. Charles region and my soil is mostly clay. What is causing the browning? Should I get rid of the compost? How do I correct the damage?
Climate conditions could be the cause of the brown needles. There was strong west wind this past winter season, which caused winter burn. With last fall’s rain and winter snow cover, the soil never dried out. According to Todd Mohr, sales associate, Rich’s Foxwillow Pines Nursery, Woodstock, pines normally begin
to go dormant in late August. “We had a lot of burn on our evergreens which showed up over summer,” says Mohr.
Cut a sample of the branch and make sure the plant is alive. You can photograph your tree or take the sample to an arboretum or garden center for evaluation. The compost should not affect the trees unless you have a large pile that is prohibiting air circulation. Spread the compost loosely over the area.
White pine is a native Illinois tree. It may come back on its own. If not, have a tree professional diagnose it.
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.
What is the largest tree that one can plant? We are trying to replace some 7- to 8-foot trees that were recently destroyed.
Trees sold at garden centers that are 2.5 to 3 feet tall, with a 2.5 inch diameter trunk, can be planted by hand. A hole for a ‘balled and burlap’ tree with a 5 to 6-inch diameter trunk can be dug by hand without a tree spade.
Any tree with a trunk larger than 6 inches in diameter would need a tree spade to do the moving and digging. Even large trees, such as a 35-foot tall tree with a trunk 9 or 10 inches in diameter can be transplanted with proper equipment. “Spruces 30 feet tall can be installed easily with a tree spade,” according to Greg Oltman, owner, Gro Horticultural Enterprises, Huntley.
Now that bedding impatiens (I. walleriana) are not recommended because of impatiens downy mildew, what are three good annuals for shade?
Chris Williams, production manager, K&W Greenery, Janesville, Wisc.
I like New Guinea Impatiens. They make nice bushy plants that are full of large colorful flowers and are easy to grow. You also get a large color selection with New Guineas. The SunPatiens and Bounce impatiens are fairly new plants, and they are recommended for sun as well as shade. Then there’s coleus. Who doesn’t like its colorful foliage? Many varieties grow upright, but others also spread. Torenia, also known as wishbone flower, has trumpet-like flowers of white, yellow, rose and purple that cover nicely mounded, low-growing plants.
Karen Wedel, manager of the outdoor floral department, Wedel’s Nursery, Garden Center, Kalamazoo, Mich.
One of my favorites is begonia. Tuberous varieties have large colorful blooms; wax begonias are good for mass planting. I’m also a fan of the big leaf, 16-20 inch tall Whopper series with large waxy leaves and summer-long flowers.
Another idea is coleus and caladiums. They come in different foliage colors, work great in gardens and containers. They are both also easy-care.
Finally, torenia or wishbone flower, named for the small “wishbone” inside the mouth of the pink, yellow or blue-purple flowers. Blooms all summer. Some varieties will trail.
Kevin DeBoer, manager, Big John’s Farm Market and Greenhouse, Chicago Heights
My favorite is Dragon Wing begonias. They’re usually sold in 4½ inch pots or hanging baskets. At my house I removed them from the baskets, then planted them in the ground in full shade. They turned out awesome! Plain wax leaf begonias are also good.
In addition, I like coleus. They don’t produce flowers, but they have many different vibrant leaf colors. In full shade New Guinea Impatiens will flower sparingly, but if you put them in some sun, they will flower more.
I have read that purple coneflowers (Echinacea) are a good source of food for birds in the winter. Will they be okay if not trimmed back until spring? If so, how early should they be trimmed?
If your coneflowers remain standing over winter, the seed heads will be available as bird food and will also be an attractive presence in the winter garden. They should be cut back in early spring before April. If you prefer, you can cut the plant back after frost and throw the seed heads on the ground.
What plants do you predict will be best sellers this year? Why?
Bryon Angerman, nursery manager, Alsip Home & Garden, St. John, Ind. and Frankfort, Ill.
I believe these two compact hydrangeas will be hot plants this year. First is Invincibelle Wee White® hydrangea, a compact and reblooming white variety of ‘Annabelle’ hydrangea. Its dwarf habit of 18-24 inches and versatile adaptability to full-sun to part-shade planting locations will yield three to four months of continuous flowers on sturdy stems. It’s sure to become a staple in every landscape. Also look for Mini Mauvette hydrangea for similar habits with pinkish purple flowers.
Molly Hornbaker Blogg, nursery manager, Hornbaker Gardens, Princeton.
Hydrangea Little Quick Fire will be a best seller this year. It blooms early with pure white flowers turning to pink, then rose. Its more
compact size, at 4-5 feet and fits into most urban gardens better than most other panicle hydrangeas. Hosta ‘Autumn Frost’ is an attention grabbing plant with powder blue leaves and showy yellow margins. Last year’s Perennial of the Year, Asclepias tuberosa, should continue to be a big seller because of its gorgeous orange flowers and because it is a host for monarch caterpillars.
Jennifer Brennan,horticulture information specialist, manager of education, Chalet, Wilmette.
Being at a retail garden center and nursery, I get to hear customers’ requests and questions about plants for their gardens. Being on the board of the Perennial Plant Association for 6 years, I get to hear hybridizers and growers claims about the “BEST” plants. It is wonderful when the claims of the hybridizers and growers match the requests of the gardeners and designers. The other fact that is worth stating is that the plants are trialed much better than in the past, so there is proof from many areas of the country that the recommended plants will perform and survive.
The first plant that I expect to be a good seller is one that has been selected by the members of the Perennial Plant Association as the Perennial Plant of the Year for 2018. It is Allium ‘Millenium’. Allium ‘Millenium’ is one of the very best ornamental onions. Unlike spring-blooming Allium bulbs, this hybrid Allium blooms in mid to late summer with large large 2 inch rose-purple, globe-shaped flowers over shiny deep green strappy, grassy foliage. Mature plants have dozens of globes covering this perennial plant. Allium ‘Millenium’ attracts butterflies and bees love it as well, but deer and rabbits stay away. This Allium is good for winter hardiness Zones 5-9; prefers full sun to part shade and is 10-12 inches tall.
second plant is a flowering perennial Echinacea. It is Echinacea KISMET™ Raspberry and it is different due to sheer flower number and a fabulous habit. It blooms first year, early in the season, with large flowers and continues until a hard frost. It is a great plant! I saw it in trials in the Chicago area and in Colorado. It attracts butterflies and hummingbirds. It is a wonderful cut flower with a great fragrance. It is deer resistant. It is hardy from Zone 4 to zone 10. It forms an upright mound that is 16 inches tall by 24 inches wide, up to 18 inches in flower. It is a beautiful hot pink color that blooms June, July, August, September and October. And, it likes average well drained soil in full sun.
The third plant is a hybrid of a native grass. Native plants are one of the strongest trends in gardening these days. The natural beauty of native Blue Grama Grass is raised to a higher level in Bouteloua gracilis ‘Blonde Ambition’. Its allure includes an abundance of horizontal seed heads, which resemble elegant, petite flags. They emerge chartreuse and transform to blonde. These exquisite blooms hover above thin, blue-green, two-foot stems. ‘Blonde Ambition’ was named a 2011 Plant Select® Winner for its resistance to pests, exceptional performance in low water conditions, retail appeal, and long-lasting attractiveness in gardens and containers. It pops right back up after snowfall. Bouteloua gracilis‘ Blonde Ambition’ was discovered and introduced by David Salman of High Country Gardens. It is easily grown in average, dry to medium, well-drained soils in full sun. It tolerates a wide range of soils, except poorly-drained, wet ones. It is hardy from Zone 3 to Zone 10. It is a tufted, warm season, Missouri native grass noted for its distinctive arrangement of mosquito larvae-like seed spikes which hang from only one side of its flowering stems. It is native to prairies, plains, open rocky woodlands and along railroad tracks. It has narrow, bluish-gray leaf blades (to 1/4 inch wide) that typically form a dense clump growing 12-15 inches tall. Foliage turns golden brown in autumn, sometimes also developing interesting hues of orange and red. Inflorescences of blond colored flowers appear on arching stems above the foliage in early to mid-summer, typically bringing the total height of the clump to 20 inches tall.
All three of these should be at the top of the selling lists for the 2018.
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?
I am interested in growing fruit trees in my suburban DuPage County yard. Can sweet cherries be grown here? Can you suggest varieties of apples, pears, peaches, apricots and plums that are hardy and disease resistant?
Can I purchase multiple issues of the magazine?