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A couple years ago when I created a walking path through my garden, I put down black plastic and covered it with wood chips. The chips are now breaking down and forming a compost that is spouting weeds and plants in the path.  If I remove the growth and replenish the wood chips, I’m afraid the same thing will keep happening. Grass is not an option due to the confined area.  Do you have any other suggestions for a natural path?

In our opinion, a plastic weed barrier should not be used under an organic mulch. This is especially true if a shredded wood mulch is used, as these mulches tend to break down fairly quickly.

This generally does not pose a problem when used as a mulch around trees and shrubs. In fact, the decomposition of the shredded bark aids in improving the soil. The mulch itself is an effective weed barrier if it is replenished regularly and maintained at a depth of 3 to 4 inches.

The plastic weed barriers are useful in preventing weeds under inorganic mulches such as pea gravel or crushed stone. Perhaps these could be considered for your pathway. Another option to consider would be decorative stepping stones.

The Clematis montana ‘Grandiflora’, I planted this spring is healthy, but one stem grew to 6 to 7 feet while a couple others at the base are only a foot long. To encourage denser growth, should I have been pinching it back throughout the summer? To get thicker growth next year what should I do now (if anything) and next spring?

Probably the most frequently asked question about clematis concerns pruning. Clematis are generally divided into three groups for pruning purposes. Your Clematis montana falls into Group A, which includes spring-flowering varieties whose flower buds were produced during the previous season. Therefore, any growth that is removed between late autumn and early spring will cause that much flower loss for the coming season. So, any pruning that you want to do to control the plant should be done in early summer. I wouldn’t be too concerned about encouraging dense growth, however, since Clematis montana is an extremely vigorous grower.

For your information, Group B varieties also bloom on the previous year’s growth. The recommended time to prune is February or March to remove weak and dead stems. The remaining stems are cut back to just above a pair of good green buds.

Finally, Group C consists of these Clematis that bloom only on new growth. Pruning these varieties involves cutting back all of the previous season’s growth to a pair of good buds usually about 10 to 12 inches above the ground. This should be done in February or March.

I have a 3 foot x 10 foot grassy area in hot sun all day.  I want to replace the grass with a low groundcover that can handle occasional, light foot traffic.  Due to the sun exposure, it would be nice if it were drought tolerant also. Can you suggest a few?

Before we mention the types of plants to be used, let’s first discuss the ground preparation. Since this planting will be subjected to heat and drought stress, as well as some compaction due to light foot traffic, the soil should be dug at least to a depth of a full spade (a minimum of 8 inches) and turned to break up any large clumps. Spread a 2 to 3 inch layer of sphagnum peat over the area and continue turning the soil until the peat is thoroughly mixed and the soil is fine and crumbly.

If foot traffic occurs in a few designated places, you might try placing decorative stepping stones there to absorb most of the compaction. You may allow the groundcover to grow around and over most of the stones if desired.

Groundcovers to select from include: bearberry, sedum (low types), thyme (several varieties), and yarrow (tomentosa).

Once again this year, my impatiens grew to about 24″ tall (they are in dappled shade). I fertilized occasionally with Bloom Builder, which has a higher proportion of phosphorous. The quality and quantity of the blooms were very good, but not quite as prolific as the low-growing types I have seen. Are there specific varieties of impatiens that are low-growing, and if so, what are some of the names? If not, what can I do to encourage lower, bushier growth?

Understand that the amount of shade will directly effect the height and bud count on all varieties of impatiens.

Since the sun is a natural growth retardant, plants tend to stay shorter and will have considerably more flower power. If you are dealing with heavier shade and desire shorter plants, try spacing impatiens further apart when planting next spring. Impatiens are natural spreaders, forming a low ground cover…but once they grow together the growth goes up instead of out. If you are used to a 6 inch spacing, try an 8 inch spacing to prolong the bushiness and control height for a longer period.

There are several shorter varieties of impatiens. Both the Super Elfin and Accent series are heavy bloomers, come in a wide assortment of colors, and stay shorter than other varieties.

Where do slugs inhabit during the day? I never see them when turning and working the soil in my garden, yet my hostas have the typical holes that slugs chew. Since they move so slowly, I wondered how far and from where they travel to feast on my plants.

Slugs have become a common pest in Michigan gardens. They are not insects, but rather members of the mollusk family, which is related to clams, oysters and octopuses. Slugs are similar to snails, but they have no visible shell. Their bodies require moisture and dry out quickly in the sun. For that reason, they hide during the day and come out to feed at night or during cloudy, rainy weather. Slugs move slowly, relying on a large foot for locomotion. They secrete a slimy mucus that eventually hardens behind them, leaving a visible trail.

Their hiding places include rocks, boards, leaves and other damp areas. They will use crevices and holes made by other creatures such as earthworms. As long as their resting place remains moist, they may travel the same route to their food source each night.

Slugs also need moist, shady areas to lay their eggs. Egg masses can hatch in 2-4 weeks or remain dormant for a very long time if dry conditions persist. They reach maturity in 5 months to 2 years. They feed on a wide variety of vegetation, but do have their preferences. As many gardeners know, hostas, with their dense canopy of foliage, are one of their favorites.

This spring, I planted climbing roses that are now weaving through a supporting trellis. I have read where the canes should be removed from the trellis, laid down, and mulched for winter protection. Is this necessary? (Besides the hassle, I am worried that I might break the canes when I untwine them from the trellis).  If it is necessary, what do people do with their climbing roses when they are a few years old and there are numerous, thick canes?

Climbing roses should be given some amount of winter protection in order to assure survival during Michigan winters. Climbing roses planted in open, exposed areas, especially those receiving northwest winter winds, should be treated as described in the question.

Removing the canes from the trellis, laying them down, and covering them with soil is a little extra work, but it is the best way to protect the rose and your investment. Climbing roses in less exposed areas can be protected by wrapping the canes with burlap and mounding soil over the crown of the plant.

Wait until the leaves have browned and the plant has gone dormant before initiating any winter protection measures. This is usually late November for our climate. Remove the winter protection prior to growth in the spring. Covering too early or leaving the rose covered too late in the spring can both harm the plant and reduce its chance of overwintering successfully.

Are there any Japanese maples that do well in dappled shade? If not, could you suggest a few that might at least tolerate dappled shade – I would like to experiment with one or two.

Most Japanese maples (Acer palmatum) will tolerate a partial shade exposure; however, color and growth rate may be reduced. Japanese maples planted in a shade environment will not exhibit the same color intensity as those planted in the sun. Further, fall color intensity is often reduced. For best results, plant a green-leafed cultivar such as ‘Viridis.’

I planted Stella D’Oro lilies so that I would have constant bloom all summer long, since this is what they are supposed to do. However, mine bloom for about a month and then stop entirely. They then form large, green pods.  Should I be removing these pods?  Also, any tips on how to extend the blooming period?

First of all, you need to be aware that Stella D’Oro is not a continued bloomer, but rather a repeat bloomer. This means that it should bloom again for you later in the season, but not continuously all season long.

As far as general culture and routine care are concerned, removing the young seed pods should allow the plant more energy to develop new flowers rather than seeds. Also, for the greatest number of flowers, daylilies need to be fed in early spring and again in summer with a balanced fertilizer at the recommended rate. Although daylilies thrive in sun or shade, they bloom the best if they are in sunlight at least half the day.

Finally, to maintain vigor and flower size, daylilies should be divided every three to five years. You can do this anytime, but you would probably want to wait until plants go dormant in the fall.

After poppies are done blooming, what should I do with the dark brown heads – should they be cut off immediately, this fall, or not until next spring?

Once poppy flower petals have fallen, it is best to remove the seed head as soon as possible. Cut the flower stem as close to the base of the foliage as you can. Since the plant does not have to form seed, it can now spend its energy developing a larger, more vigorous plant for next spring.