Covering a pergola

What can I grow over my pergola? I have tried clematis but they never even get tall enough to make it up the sides, let alone over the top. My soil is heavy clay.

Assuming your pergola gets plenty of sun, clematis should work well. There are many types of clematis though, some that stay much shorter and daintier than others. For a robust type, I would look at the viticella group, which includes Etoile Violette, Polish Spirit and many other fast growers. Sweet Autumn clematis (C. terniflora or paniculata) is a fairly rampant grower as well.

After choosing the right type, be sure to plant the clematis deeply, in heavily amended soil to get it off to a good start. Members of the viticella group should be cut back hard each spring when the leaf buds just begin to swell. This will encourage lots of new growth and flowering. After two or three years of this treatment, your clematis should have no trouble scaling a pergola in a single season.

Other options include grape vine (Vitis ssp.) or porcelain vine (Ampelopsis brevipedunculata ‘elegans’), Virginia creeper and Boston Ivy, all of which are known for their vigor. The only drawback to these tough plants is Japanese beetle damage. If you have Japanese beetles, these vines are a favored food. Trumpet creeper (Campsis radicans) will cover a pergola easily and has few, if any, pests. An array of new cultivars is available now in reds, yellows and coral. ‘Mademoiselle Galen’ is a lovely choice. Hops vine (Humulus ssp.) is fantastic for covering structures and has the added feature of being herbaceous. That means non-woody, so you cut them back in late fall or early spring and the new growth will shoot out of the ground like asparagus spears, increasing each year. Golden hops has pretty chartreuse leaves that turn green in midsummer.

If your pergola is in shade, you may need to choose between Akebia (Akebia quinata) and Dutchman’s Pipe (Aristilochia durior). Dutchman’s pipe is host to the larvae of pipevine swallowtails and has large heart shaped leaves that hang in layers. Akebia has pretty five part leaves and little chocolate red flowers in May. The grape family vines mentioned above are often untouched by Japanese beetles when grown in shade because the beetles prefer to feed in sunlight.

It’s also important to match the way a vine climbs to its support. Some woody vines (like Boston Ivy) climb by little rootlets and holdfasts along the stems that do better on brick, wood or other solid, rough surfaces. Some vines (like sweet peas) twist themselves around by a response called thigmotropism and will do well climbing towers, poles and other supports they can lasso. A few, (like Clematis) twist their petioles (leaf stems) around wires and twigs, so they do best on mesh, trellising and string supports. Some ‘climbers’, like roses, don’t climb at all and must be tied to supports.

Very often, when a vine doesn’t climb, it is because it is not provided with something it can hold on to.

Deck screening

I need ideas for screening the view from my neighbor’s dining room window to my deck. I planted arborvitae that are about five feet tall. How fast do they grow and what else can I do?

Arborvitae grow fast, but if your deck is raised above ground, it may be a while before they do much serious screening. If you have a deck rail, you may want to try ‘hayracks’ planted with annuals that trail, as well as some that get tall, like grasses and cannas. This will give minimal screening, more to draw the eye rather than totally block the view.

For foolproof screening, you might consider the new rage in garden decorating with textiles. From a few pillows to entire outdoor bedrooms, bringing soft goods, lamp lighting and furnishings outdoors is very popular. A simple canvas or cotton duck drape, hung by stainless steel cable (available at home stores) will give you instant privacy. Add some tropical foliage, a floor lamp and a comfy chair and your deck becomes a retreat.

Amend or plant native?

There is only so much we can do to amend our soils; at some point the plants we grow hit the wall of clay. Do we try to amend anyway, or plant things that are better suited to clay? If so, what?

A combination of both actually. Changing the texture of soil is only one reason we amend; the other is to add nutrients. Side dressing (adding layers of material around the base of plants) with compost, mulch and leaves will definitely enhance soil over time. But you are right to think of using plants that simply like clay.

My former home was the site of an old brick factory and my soil was gray/blue ‘modeling clay’ that you had to peel off of the shovel. Still, I grew many fine plants there.

Among the trees that have performed well in clay are Hornbeam (Carpinus betulus), Washington hawthorn (Crataegus phaenopyrum), ginkgo (Ginkgo biloba), Kentucky coffee tree (Gymnocladus dioica), and green ash (Fraxinus pennsylvanica). Green ash is probably a ‘wait and see’ tree right now because of the emerald ash borer. Several oaks either prefer or tolerate clay including shingle oak (Quercus imbricaria), bur oak (Quercus macrocarpa), white oak (Quercus alba), and Hall’s oak (Quercus ellipsoidalis).

Evergreens include Norway spruce (Picea abies), ponderosa pine (Pinus ponderosa), and mugho pine (Pinus mugho). Ubiquitous as they are, yews (Taxus) did very well for me on clay.

Shrubs that do well in clay include Witch hazel (Hamamelis virginiana and intermedia), Chokeberry (Aronia arbutifolia), Amur maple (Acer ginnala), Deutzia (Deutzia cultivars) and cotoneaster (Cotoneaster cultivars).

Perennials that did well in my clay included beebalm, peonies, daylilies, Miscanthus grasses, salvia, baptisia, spiderwort and cranesbill.

When planting in heavy clay, it is more important than ever to create planting beds instead of sticking things into spots on a lawn. This allows you to top dress the soil twice annually. Also, I had better luck with bare root and small containerized woody plants than balled and burlapped. Apart from the fact that B&B plants have most of their roots removed in the digging process, you are automatically filling the hole with foreign soil, possibly creating that ‘bathtub’ effect. If the plant was originally grown in loam or sand, its roots may just circle around in the soil ball instead of penetrating the clay. For the same reason, it is not advisable to amend soil by placing compost or soil mix in the hole when planting woody plants. Back fill with the same soil you dug out.

Incidentally, the spot at the base of tree trunks that flare out slightly should be just above ground when planted; this is especially important in heavy clay soils.

Rusty lawn

Every fall my lawn gets covered in rust. It’s so bad that it comes off on my shoes and pant legs when I walk across the grass. What can I do to prevent this?

Rust disease on lawns is a fungal infection that thrives and spreads during warm, dry weather in late summer and fall. The fungus can be treated with a spray of sulfur-based fungicide at three to five day intervals until symptoms disappear. However, the prevention of rust is more complex and requires a ‘re-thinking’ of common lawn care practices.

A healthy lawn should be cut high (three inches) to promote nourishment to the roots. Since food is manufactured in the green leaf blade (photosynthesis) it makes sense to leave as much of the leaf blade as possible. ‘Scalping’ lawns also allows sunlight to reach weed seeds and promotes a weedier lawn.

Chemical fertilizers allow salts to build up in soil and kill enzymes, microbes and even earthworms that are essential to healthy soil. Preserving biological activity will ensure that living soil and healthy roots work together to make stronger plants that ward off disease. Use Ringers, Restore or Milorganite lawn foods instead.

Watering is the most critical aspect of preventing fungal disease. Most sprinkler systems water for less than 20 minutes, every other day. Folks who set up sprinklers tend to throw a lot of water in the air and upon seeing run-off, think that the soil is saturated. Even worse, some people water their lawns by holding the hose while they take in the evening air. This practice guarantees shallow, weak roots that are dependent upon such watering for survival. Weak plants then succumb more easily to infection. A constantly damp soil surface also allows the spread of the fungus. Watering should be done only during drought periods (10 days without rain) and then at least three inches of water should be slowly and carefully applied to soak to a depth of eight inches.