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.
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.
Miniature gardening is the rage. What enchanting miniature plants work well in a shaded area?
Many miniature plants grow in shade. Some unusual ones are the 6-inch tall Solomon’s seal (Polygonatum humile ‘Tom Thumb’), the 2-inch tall Ajuga reptans ‘Planet Zork’ and two cultivars of the very slow-growing conifer Cryptomeria japonica: ‘Koshyi’ and ‘Tenjan’. Or look for two European gingers, Asarum forlesii ‘Mercury’ and Asarum takaoi ‘Roundabout’, which are about 3 inches tall. Also: the maidenhair fern (Adiantum venustum), mosses and miniature hostas
The best and most obvious answer is miniature and small hostas. From the ever-expanding “mouse” series with ‘Holy Mouse Ears’, ‘Mighty Mouse’ and ‘Giantland Sunny Mouse’ to newbies such as ‘Mini Skirt’, ‘Ladybug’, ‘Baby Booties’ and ‘Little Starlet’… perfection! Add some grass-like carex such as ‘Beatlemania’ for texture, miniature Solomon’s seal (Polygonatum humile) and dwarf heucheras from the Little Cute series, and your garden fairies will be in heaven.
If you’re planting in the ground, these low-growing perennials will add interest and texture to your garden: Irish and Scotch moss (Sagina sublata and S. subulata ‘Aurea’ – best in part shade), brass buttons (Leptinella squalida) and miniature hostas. Add color with annuals such as polka dot plants (Hypoestes), ‘Strawberry Drop’ coleus and torenia. It’s important to add perennials and annuals into your garden for a longer season of color.
When is the best time to cut back hydrangeas? How far do I cut them back?
Pruning hydrangeas depends on the species. Oakleaf hydrangea (H. quercifolia) and Peegee hydrangea (H. paniculata), with its well-known cultivars ‘Limelight’ ‘Little Lamb’ and ‘Tardiva’, are woody shrubs that bloom on old wood. Trim them within two to three weeks after flowering. The following year’s primary flower buds form near the top of the stems in late summer. If you wait too long to prune, you will be cutting off flowers on the old stems.
The new bigleaf hydrangea (H. macrophylla) ‘Endless Summer’ is an herbaceous plant that dies to the ground over winter and starts into new growth in spring. It can be cut at any time since it flowers on both old and new wood.
Hydrangea ‘Annabelle’ (H. arborescens) can be trimmed at any time. “It dies back totally to the ground each year so you can keep it trimmed to the size you want,” says Jean Bragdon, garden center manager at Lurvey’s Garden Center, Des Plaines.
I am interested in improving fall color in my yard. What shrubs turns red beside burning bush (Euonymus alatus)?
Wendy Vichitk, plant manager at Luurs Garden and Flower Shop, Hillside, recommends these shrubs for a colorful fall garden:
Low growing 2- to 3-foot Virginia sweetspire ‘Little Henry’ (Itea virginica) has red foliage and grows in both sun and shade. The foliage of the somewhat taller ‘Henry’s Garnet’ is dark red, as the name indicates.
Fothergilla ‘Mount Airy’ has blue-green leaves that turn intense yellow and orange-red in sun and half shade.
Oak leaf hydrangea (Hydrangea quercifolia) grows in shade or partial sun, with orange-red to red fall color.
The leaves of apple serviceberry (Amelanchier grandiflora) burn a bright orange red. There are several cultivars on the market to choose from.
Many viburnums have bright fall color. The easy to grow Korean spice viburnum (Viburnum carlesii) and the also fragrant V. juddii have leaves that produce a mixture of red, orange and mahogany. Arrowood viburnum (V. dentatum) and cranberry bush viburnum (V. trilobum) both exhibit typical red-purple color.
The intensity of color is affected by the weather. Warm sunny days followed by cool nights bring the highest leaf color. The health of the plant, its growing conditions, and the amount of water the plant receives also affect fall color.
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 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.
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.
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!
What is the green worm that eats my roses and columbine every year?
It is hard to diagnose your problem without seeing the caterpillar. There are several green worms that bother roses, and one can be controlled with Bt (Bacillus thuringiensis) but rose slug, for example, cannot. Proper identification is necessary before applying any control method. Do not use an insecticide for anything that"s not on on the product label. Do not use any insecticide as a preventive measure. It doesn"t work and ends up being harmful to the environment and a waste of your money.
Green worm on your columbine could be an inch worm or canker worm. If the caterpillar loops up in the center or arches as it moves along, it could be a looper or cabbage worm. Leaf miners, which are usually white or pink, tunnel in the leaves. “To eliminate insects, use insecticidal soap,” said Nancy Clifton, Chicago Botanic Garden Plant Information Specialist.
For an exact diagnosis, consult your local University of Illinois Extension service or collect a specimen and bring it to the Plant Information Service at the Chicago Botanic Garden or the Morton Arboretum.
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