I have a clematis on an obelisk and all the leaves are brown. Do I remove those and cut down the clematis? If so, how much should I leave, or should it be cut back to 4 inches above ground?

A clematis can look quite brown and dead after a long winter. It is tempting to cut it back to the base, along with other perennials that benefit from this tidying up. However, the clematis is the poor man’s pruning minefield. The key is knowing when your clematis blooms, for that determines the “when,” the “what,” and “how much” to prune. Spring-flowering clematis (April-May) flower on their old wood (previous season’s growth). Pruning before flowering removes their blooms. Once flowering is finished, old stems can be cut back in early summer, enabling new growth to ripen the rest of the season for next spring. Clematis alpina, Clematis macropetala and Clematis montana fall into this first category.

The second clematis group flower on short stems produced on last season’s old wood. These are the early large-flowered hybrids, the double and semi-double flowers, and the mid-season hybrids which flower by the end of June. Pruning is essentially light. Remove dead, broken or weakened stems. Watch out you don’t remove a vine at the plant base that has flowering buds higher up. Varieties in this group are ‘Miss Bateman,’ the well-known ‘Nelly Moser,’ ‘Duchess of Edinburgh,’ and ‘General Sikorski.’

The third clematis group only flower late in the season, well after mid-June and into autumn. They only flower on new wood. Pruning involves cutting back all the previous year’s growth to just above a good pair of buds, about 10 to 12 inches above ground. Don’t prune this type of clematis any earlier than the end of February or beginning of March. Hybrids in this category are ‘Jackmanii,’ and the Clematis viticella cultivars.

Knowing when your clematis blooms is the key to making an informed pruning plan.

What effect will the late April, heavy snowfall have on bulbs, perennials, shrubs and trees this season? Is there anything I should be looking for or doing this summer because of it?

Actually the snowfall was like a slow-release watering for most of the plants in question. Some of the more delicate bulb blossoms succumbed more quickly and we didn’t get to enjoy their wonderful flowers as long. Perennials were just starting to emerge and welcomed the slow drink of water. The melting snow was a far better source of early season moisture than several downpours. Heavy rainfall can quickly flood and set new root growth to rotting because the soil hasn’t had the chance to warm up and process that much water. The ground is still waking up too!

The downside for shrubs and trees is the wet snow sticks and applies a lot of weight to branch structure. Any broken tree limbs or shrub branches should be properly pruned out and removed. Shrubs may need to be reshaped for aesthetics or replaced if snow broke out the center crown. Be on the lookout for insects or funguses that might home in on the pruning cuts this early in the season. Make sure injured trees and shrubs get plenty of consistent water and air circulation to help their healing process. Sometimes a young tree sapling, like a maple or pine, may lose a central leader. It is important to train and shape a secondary leader branch to become the central upright to maintain the natural configuration and strength of the tree.  Otherwise you have a tree that grows with a flat top, becomes top heavy as secondary branches fight for dominance, and becomes a candidate for further storm damage.

I would like to use a copper trellis to support climbing roses on a hot, south-facing wall. Will the copper get too hot and harm the rose canes that touch it?

Trellises and arbors are great garden accents that provide support and definition for vining or trailing plants. If not for support, these plants would meander aimlessly around the garden. Trellises and arbors with established plants can be used to provide interest to blank walls, frame other garden ornaments or provide a dramatic entrance to the garden.

The most popular material for trellises and arbors is wood. However, iron, copper, or other metal trellises are once again becoming popular. They lend a feeling of stability and elegance to the garden, and, in fact, are quite long-lasting when properly maintained (unpainted iron, for example, will rust).

Growing plants on metal arbors or trellises poses no particular problems. The vines will shade the metal as they grow, keeping it from absorbing excessive heat.

How do I propagate boxwood? Would it be through cuttings? How and when should I do it? I want a low hedge for a perennial cottage garden like I’ve seen in England, but there’s no way I can afford to purchase that many boxwood.

Boxwood can be easily rooted from cuttings nearly anytime with the use of rooting hormones and a high humidity environment. Unfortunately, it would take several years for the plants to reach any noticeable size (the main reason why boxwood cost what they do). For hedges like yours, 1 gallon starter plants should be a cost effective way to begin your hedge, and with much faster results. While boxwood grow well throughout England, one must be careful as to where to plant them here in Michigan. An eastern exposure gives good protection from winter winds and sun, both of which can severely damage the foliage.

Please recommend annual vines with bright flowers. I want to grow them in full sun on a tall trellis (they can grow 10 to 20 feet).

There are several annual vines which will grow in full sun and give you plenty of color most of the summer. Here are a few:

• Morning glory, which comes in blue, white, pink, and red, is a fast-growing vine that blooms from July until frost. It is easy to grow, even in poor soil conditions.
• Hyacinth bean can reach up to 15 feet in one season and has beautiful lavender flowers and purple bean pods. The foliage is an attractive dark purple/green.
• Cardinal vine has bright red flowers and grows quickly up a trellis. You can easily start this Ipomoea from seed.

What is the difference between own-root and grafted roses? Is one better than the other?

Own-root roses are produced by rooting and growing the cuttings of desired varieties. The types produced by this method often include Antiques, Flower Carpet, Meidiland and many Shrub varieties. Most own-root roses do not need ground level protection in winter once they are established. Budded (or grafted) roses are produced by inserting a bud of a desired variety onto a vigorous rootstock. The types produced by budding include Hybrid Teas, Grandifloras, Floribundas, Climbing and English varieties, as well as a few from the Antique and Shrub groups. Budded roses should be planted with their swollen bud union 1 to 2 inches below the surface, plus have winter protection each year to help them survive our cold Michigan climate.

Very few rose varieties are produced using both methods, so the question of one method being “better” than the other really does not apply. Since the propagation method relates to the type of rose, your choice is really determined by the rose producers and their experience of which one works best for that particular variety.

Flickr / sigusr0Fertilizing the plants

It is important to get your soil analyzed by your county MSU Extension, but in the absence of a soil test, apply one pound of 12-12-12 fertilizer per 100 square feet one week before planting. Two weeks later sprinkle an additional two to three pounds of the 12-12-12 as a side dressing, making sure not to get it on the damp foliage.

The fertilization strategy changes after the first year. Fertilize the June-bearing plants immediately after harvest with 2 to 3 pounds of 12-12-12 per 100 square feet and avoid early spring fertilization because it can cause the plants to grow too fast and produce soft berries and a smaller yield.

Everbearing strawberries are fertilized the same as June-bearing plants in the planting year. During the subsequent years, the everbearing plants should be fertilized with 1/2 pound of 12-12-12 per 100 square feet, with applications made in early June, July, August and September. In total, about the same amount of fertilizer is used for both types of strawberries, but for the everbearing, the fertilizer is spread out over four applications throughout the growing season.

Flickr / sigusr0Training the plants

There are three training methods for strawberries: the hill system, the spaced runner system and the matted row system. The matted row system is the most common one for the backyard grower. It is the least labor intensive, but may yield smaller berries. Set the plants 18 to 24 inches apart in the row with 3 to 4 feet between rows. The runners that develop from the mother plants root in a bed that is about 12 inches wide. If the bed gets overcrowded with plants less than 6 inches apart, thin by removing the weaker daughter plants. Daughter plants form from a mother plant 4 to 6 weeks after planting and then they root and fill out the row. The row width should be maintained at about 12 inches.

On June-bearing plants, it is important to remove the flowers the first season so that the plant’s energy is devoted to the daughter plants that are filling out the row. Of course, you won’t get any fruit the first season, but there is a big pay-off in the second season. On everbearing strawberries, it is important to remove the flower and fruit trusses for the first 60 days after planting. This will result in a small fall crop in the first year.

Come back tomorrow for more on fertilizing strawberries…

Flickr / sigusr0Planting & growing tips

Strawberries require full sun and need to be planted away from “frost pockets”—areas that are low-lying where cold air drains in the springtime. When choosing a site, avoid areas where strawberries, tomatoes, potatoes, eggplants or peppers were planted within the last four years. These plants can act as host to a soil-borne disease called verticillium wilt. Sandy loam to loam soil that is high in organic matter and slightly acidic is preferred. The most important consideration is drainage, as strawberries have shallow roots and cannot tolerate any freestanding water. Lots of organic matter will improve drainage in clay soil and increase water-holding capacity in sandy soil.

Purchase plants that are certified disease-free instead of getting plants from family, friends and neighbors. These healthy plants will be large and have numerous light-colored roots. Plant them in early spring as soon as you have properly prepared the soil. Bare-root strawberries can be planted from late March to early May.

The holes should be big enough so that you can place the roots straight down and spread them out. The midpoint of the crown should be level with the soil surface. Tamp the soil lightly around the roots to get rid of any air pockets. Bare-rooted plants should not be allowed to dry out. They can be kept in a refrigerator at a temperature of 40 degrees. You can dip the plants in water while they are waiting to be planted, but don’t leave them soaking in the water.

Come back tomorrow for more on training strawberries…