Q. I would like to grow goldenrod to add color to my autumn garden. However, I keep reading that it causes hay fever.
A. Goldenrod needs a good press agent. Not only is it falsely maligned as a common sneeze-causing weed, but it has also been oversimplified as one single plant.
Goldenrod does not produce hayfever. Its pollen is too heavy and sticky to be carried by the wind. Most hayfever is caused by the fine, light, dry pollen produced by the ragweed, a common weed blooming at the same time as goldenrod.
While goldenrods may look similar at the outset, they are all quite different, in both aspect and behavior -- from the ubiquitous and forceful, to the graceful, refined and rare.
Two common types, the tall goldenrod, Solidago altissima, and Canada goldenrod, Solidago Canadensis, may be the goldenrods people think of when picturing autumn fields. Though both are natives, these plants' creeping rhizomes can take over gardens. Instead, you may want to try the following native goldenrods in your garden:
• For sunny, dry sites, try old-field goldenrod, Solidago nemoralis, and showy goldenrod, Solidago speciosa.
• For sunny wet sites, such as rain gardens, try Riddell's goldenrod, Solidago riddellii, and rough goldenrod, Solidago rugosa.
• Finally, to brighten up a shady spot, try blue-stemmed goldenrod, zigzag goldenrod, Solidago flexicaulis, and elm-leaved goldenrod, Solidago ulmifolia. For those with limited gardening space, goldenrods also can be grown quite successfully in containers.
Goldenrods offer the perfect setting to watch a bewildering variety of insects eating, mating, and stalking their prey. Goldenrods and other fall-blooming plants offer our local pollinators the last chance for them to put away reserves for winter.
Q. How do I get rid of moss?
A. Since Mother Nature dislikes bare patches of soil, she sees to it that exposed areas fill in with plants -- or weeds, depending on your viewpoint. Moss happens to be nature's favorite filler for areas that have shady, moist, acid soils with low fertility. Since they obtain all their nutrients from the air (moss has no true roots), moss plants require nothing more than shade, acidic soil, and adequate moisture to flourish.
While removing moss works in the short term, it will continue to come back as long as your soil meets the moss's criteria for good growing conditions. Therefore, you have to treat the cause, not the symptoms.
There are several steps you can take to prevent moss:
• Prune trees and shrubs that shade your flowerbed.
• Get a soil test to evaluate your soil quality. Adjust your soil's fertility and pH based on the test's recommendations. If your flowerbed contains acid-loving plants such as rhododendrons and azaleas, you may not want to add lime to your soil.
• If you have compacted, poorly drained soil, dig in 1 to 2 inches of compost to improve the soil's fertility and ability to regulate moisture. During dry periods in the spring and summer months, water your flowerbeds for 30 minutes once or twice a week instead of for a few minutes each day. This allows the soil to dry between waterings and also encourages your plants to develop more extensive root systems.
• But perhaps the best solution is to beat nature at her own game and, after amending the bare spots with compost, fill them low-growing groundcovers that perform well in shade include lungwort (Pulmonaria spp.), ginger (Asarum spp.) and liriope (Liriope spp.).
If all else fails, try to enjoy the moss for what it is -- a self-planting, maintenance-free, no mowing, no fertilizer or pesticides, and actually no watering to survive (moss can go dormant and dry for months on end). Growing moss has fast become an increasingly desirable alternative to grass lawns and conventional shade gardening plans and is used in shaded slopes, pathways, water gardens, and rock gardens. For centuries the Japanese have known what we are finally realizing -- gardening with moss adds an amazing degree of serenity and timeless beauty to any garden. Unlike grass that turns browns in winter, moss actually likes colder temperatures and stays green all winter long.
• Provided by Mary Boldan, University of Illinois Extension Master Gardener. Send questions to Ask a Master Gardener, c/o Friendship Park Conservatory, 395 W. Algonquin Road, Des Plaines, IL 60016, or via email to email@example.com. The Friendship Park Conservatory Master Gardener Answer Desk is available 9 a.m. to noon Monday, Wednesday and Friday and noon to 3 p.m. Saturday; call (847) 298-3502.