Michigan Gardener

SIGN UP to stay in touch!
We will send you occasional e-mails with gardening tips and information!


Digital Editions

Click on the cover to read now!

  • Home
  • Departments
    • Ask MG
    • Books
    • Clippings
    • Garden Snapshots
    • MG in the News
    • Janet’s Journal
    • Plant Focus
    • Profile
    • Raising Roses
    • Thyme for Herbs
    • Tools and Techniques
    • Tree Tips
  • Garden Event Calendar
  • Resources
    • Alternatives to Impatiens
    • Garden Help
    • Soil and Mulch Calculator
    • Public Gardens
  • Web Extras
  • About
    • About Us
    • Editorial Content
    • Privacy Policy
    • Contact Us

PLEASE NOTE: In the autumn of 1995, we hatched the idea for a free, local gardening publication. The following spring, we published the first issue of Michigan Gardener magazine. Advertisers, readers, and distribution sites embraced our vision. Thus began an exciting journey of helping our local gardening community grow and prosper.
After 27 years, nearly 200 issues published, and millions of copies printed, we have decided it is time to end the publication of our Print Magazine and E-Newsletter.

Pruning azaleas & yews

March 18, 2010   •   

Would you please advise me how to prune azalea bushes and yews. They are very old – I am guessing approximately 45 years, since they were here when we moved in 31 years ago. My husband has always trimmed them using electric shears and has only trimmed the top of the shrubbery, hence, all of the foliage is at the tips with a lot of wood at the center. Can I salvage these shrubs by pruning them back drastically? Will I lose them if I do so?

Shearing your evergreen shrubs will give them a neat, formal appearance, but when done year after year it can create undesirable and unhealthy results. Two different pruning methods are listed below for yews and azaleas. When used for evergreens, these pruning methods are best done before bud break in the early spring.

Renewal Pruning: Best used when shrubs are older and have become overgrown with large amounts of unproductive wood.

Method: Cut off the oldest branches near ground level leaving only productive young stems. If there are only a few young stems, remove the oldest branches over a three-year period. Prune back 1/3 of the oldest branches each year to allow even light penetration for new growth. When new shoots develop they can be thinned back to various lengths, which will develop strong branches.

Cons: More pruning cuts have to be made over a longer period of time.

Pros: Shrubs look aesthetically better during the process. Weakened shrubs have a higher survival rate when using the renewal rather than the rejuvenation method of pruning.

Rejuvenation Pruning: Best used when shrubs are unhealthy and severely overgrown.

Method: Cut all branches 6 to 12 inches from ground level. This is a drastic method and better results are achieved if followed up with proper watering and fertilizing practices.

Cons: If you are pruning a flowering shrub you could lose bloom for 1 or more years. If the shrub has been in decline for several years it may not recuperate.

Pros: Strength and vigor of new shoots are directly proportional to the amount that the stem is pruned back.

General pruning tips:

  • Use clean, sharp pruning tools appropriate for the task.
  • Remove dead, broken or diseased branches any time of the year.
  • Yews are a better candidate for rejuvenation pruning.
  • Azaleas are a better candidate for renewal pruning.
  • Always check the mature size of the shrub before planting; a properly-sized plant will require less maintenance pruning.
  • When shearing your evergreens always continue to make thinning cuts every season to allow for light penetration and inner growth.

Filed Under: Ask MG

Corsican mint for path

March 17, 2010   •   

We recently installed a rock pathway and want to fill the spaces between the stones with “step-able” plants that are low-growing and hardy. We planted some creeping thyme in the sunnier areas. I have seen Corsican mint used for this purpose in shady areas. Do you think it would do alright in southeastern Michigan?

Corsican mint (Mentha requienii) would definitely work and look nice for a very low growing (1/2 to 4 inch tall) ground cover between paving stones. The plant needs partial shade, and rich, moist soil that is well drained. It will not take drought because it is very shallow rooted. When stepped on (it will take foot traffic), it gives off a peppermint fragrance. It has small, light purple flowers in late spring and early summer. It is rated for zones 6 to 9, but many growers say it comes back in zone 5 (southeast lower Michigan). Remember it is a mint and will spread, but it is much better behaved than its relatives. It basically stays in its own area and can be controlled by removing the outside edges that have spread too far.

Filed Under: Ask MG

Plant Focus: Trillium

March 12, 2010   •   

by George Papadelis

For hundreds of years, this plant and its name have been used to symbolize purity, simplicity, elegance, and beauty. The name trillium has graced the marquees of restaurants, country clubs, resorts, software companies, consulting firms, and numerous other businesses. Every spring, many Americans journey into the woods to admire the showiest of our spring woodland flowers.

In Ohio, where all 88 counties have masses of wild trillium, it was selected as the state’s official wildflower. Its flowers have twice graced a U.S. postage stamp. Even our Canadian friends across the bridge have declared white trillium (Trillium grandiflorum) the official provincial flower of Ontario. Other parts of the world share our passionate admiration for this plant. In Europe, where trilliums are not found in nature, gardeners dedicate vast amounts of time and money acquiring them, especially rare species. In Japan, a cult-like interest has developed towards trillium.

Trillium-erectumJonathon Hofley / Michigan Gardener
Trillium erectum

Trillium species and growing conditions

The most readily available species is Trillium grandiflorum or white wake-robin. This has large, pure white flowers up to 5 inches across. These develop in great abundance throughout the northeastern U.S. Its flowers usually fade to a dull pink and sometimes red. Trillium erectum is a much more diverse species with flowers ranging from red to purple to yellow-green and beige. It also grows wild in the Northeast and Michigan. Trillium luteum is the most common yellow species. It originates from areas around eastern Tennessee. One of its most notable features is the beautiful dark green leaves decorated with pale green markings. The flowers are relatively small. Trillium recurvatum bears maroon-purple to clear yellow flowers with strongly curved petals. Several other species and a few named varieties are readily available. Most trillium grow about 12 to 18 inches tall once established in the garden.

Trilliums are North American and Asian natives that typically thrive in moist, woodland settings where rich, acidic soil is prevalent. Gardeners with some shade can create this type of soil by incorporating organic soil amendments such as aged pine bark, sphagnum peat moss, leaf mold, composted manure, or compost. During dry spells, plants may require some supplemental watering.

Trilliums typically bloom in late April or early May when dozens of perennials and bulbs are available as companions. Several spring-flowering bulbs will tolerate shade, and a few flower at the same time as trilliums. Try trilliums with daffodils, tulips, Siberian squill, grape hyacinths, summer snowflakes, glory-of-the-snow, and Anemone blanda. Pansies and violas planted the previous fall or in early spring will offer the largest color range to coordinate with your trillium flowers. Early May-blooming perennials for shade include Anemone sylvestris, foamflower (Tiarella), fern-leaf bleeding heart, leopard’s bane, and the beautiful blue-flowering perennial forget-me-not (Brunnera macrophylla). Several other woodland plants such as woodland phlox (Phlox stolonifera) and yellow dogtooth violets (Erythronium canadensis) should also be at peak bloom.

How trilliums grow

As gardeners, many of us have developed questions about growing this somewhat mystical plant. It doesn’t help that the typical nursery only sells tiny, flowerless plants that show little promise of ever coming to fruition. Perhaps the most important aspect of appreciating this plant can be expressed in one word: patience. The small plants available through nurseries are much more durable than they appear. Most species will eventually develop into clumps of flowers that are quite persistent even in less than perfect conditions. This clumping process often takes 2 to 4 years. At least it’s faster than growing them from seed. If the seed germinates, it may take as long as 10 years to bloom.

Another perplexing aspect of growing trilliums is the short period of time plants are visible in the garden. The “root” of a trillium is really a sort of underground stem called a rhizome. This rhizome stores food all winter until temperatures rise in spring. In early May, the rhizome sends up branches that typically support three leaves and a single three-petal flower. The short time during which leaves are present is the plant’s only chance to gather energy from the sun. Therefore, picking trillium flowers and leaves will diminish the plant’s ability to produce food. It won’t kill a healthy plant, but frequent picking will eventually reduce flowering. The number of flowering branches depends on the age of the plant, the size of the rhizome, and the overall energy stored in the rhizome.

Next comes the strange part. Just a few weeks after blooming, the branch and leaves wither away with no visible signs of life. The rejuvenated rhizome will await winter dormancy, which is mandatory for next year’s bloom production. Many woodland plants and spring-blooming bulbs (i.e. tulips, daffodils, crocus, etc.) enter an early-summer dormancy. These plants, like trilliums, are described as spring ephemerals. If you are thinking of shopping for a potted trillium in summer or fall, visually evaluating a plant’s vigor is almost impossible. However, a gentle probing of the soil to locate a firm, sleeping rhizome should do the trick.

Finding and purchasing trilliums

Some trillium species are considered threatened or endangered. These trillium cannot be collected from the wild under any circumstances. All other trillium in Michigan are protected as follows: The only way these can be collected is by owning the land from which they are harvested, acquiring a permit to collect them from the Department of Natural Resources, or by acquiring a bill of sale from the property owner. All trillium located in National Forests are also not collectible.

trillium-grandiflorumJonathon Hofley / Michigan Gardener
Trillium grandiflorum
Since it is legal to collect unthreatened and unendangered trillium that are located on your own land, “nurseries” can own land from which they may legally collect wild trillium. Fortunately, responsible commercial collection of trillium has had little effect on most species. Most trillium have developed stable masses in their natural habitats, and more and more nurseries are offering wildflowers that are propagated on site. As gardeners and stewards of our environment, we should seek out these sources and avoid plants that are illegally collected.

The biggest two concerns for the sustenance of trillium populations are animal grazing and urban development. Repeated grazing from deer can eventually weaken plants and wipe out large areas. In regions where deer populations have increased, trilliums have often disappeared. A deer repellent would be a wise investment if deer browse in your trillium bed. In cases where a plant’s habitat is limited, populations are also suffering from commercial development. Clear cut lumbering and urban sprawl have an enormous impact on all wildflowers. In cases where development is unavoidable, the proper agencies should be contacted to save important plants. A great source of trillium is one that has a permit to rescue plants that would otherwise fall victim to bulldozers.

Trillium are available from many garden centers as spring-flowering plants in small containers. These can be treated just like any other perennial. More and more retailers are selling them packed in plastic bags with some peat moss. Make sure the rhizomes are firm and try to plant them before the leaves emerge. Bury rhizomes horizontally about 2 to 4 inches deep in the moist, rich soil that most woodland wildflowers love.

Remember to be patient—good things come to those who wait. In time, your little plant should form colonies that you and your garden’s admirers will enjoy for years to come.

George Papadelis is the owner of Telly’s Greenhouse in Troy, MI. Fred Case and Tony Reznicek also contributed to this article. A portion of this article was excerpted from the book “Trilliums” by Fred Case and Roberta Case, published by Timber Press.

At a glance: Trillium (TRILL-ee-um)

Plant type: Perennial

Plant size: Most are 12-18 inches tall and 12 inches wide

Habit: Clump-forming

Hardiness: Most are zone 4 or 5

Flower color: White, red, pink, yellow

Flower size: Up to 3 inches wide

Bloom period: Late April to early May

Leaf color: Green, sometimes mottled with pale green, dark green, or maroon

Leaf size: Up to 8 inches long and up to 6 inches wide

Light: Dappled shade to shade

Soil: Moist but well-drained, rich in organic matter

Uses: Woodland garden, shady border

Companion plants: Spring-flowering bulbs (daffodils, tulips, grape hyacinths, etc.); spring-flowering perennials (foamflower, fern-leaf bleeding heart, perennial forget-me-not, woodland phlox, etc.)

Remarks: Patience is a must—trilliums take time to become established; the plants go dormant in summer (stems and leaves naturally wither away)

Filed Under: Plant Focus

  • « Previous Page
  • 1
  • …
  • 235
  • 236
  • 237
  • 238
  • 239
  • …
  • 285
  • Next Page »

Copyright 1996-2025 Michigan Gardener. All rights reserved.