Gardening Newsletter - October 2003, Issue 14
Although it is still fall, winter is just around the corner. As a gardener and homeowner, this is one of the busiest times of year for me, hurrying to get all my chores done before the cold weather sets in. The change in seasons was inspiration for this newsletter.
Water features, such as ponds, are becoming increasingly popular in the home landscape. If you have a pond you should be busy getting it ready for winter. In the article “Preparing Your Pond for Winter” I provide some tips on what you should do to help your pond and fish get safely through the winter.
As a shade gardener most of you probably have a lot of trees in your garden. But how closely have you looked at them, especially in the winter? Many of our customers tell me they want a lot of evergreens in their garden for winter interest. This always takes me back a little because deciduous trees (those that loose their leaves in the winter) have so much to offer the winter landscape.
In the article “Looking at Naked Trees” I try to get you to look at trees in ways you may have never done before. As a horticulturist, I’d like you to notice their beauty and unique characteristics. As a designer, I’d like you to think about their architecture and form. Hopefully I will convince you that trees are both living art and architecture.
Preparing Your Pond for Winter
If you have a pond in your garden now is the time you should be winterizing it. You pond should be winterized before the water temperature dips to 50 degrees. This is especially important if you have fish.
Fall is the time of year when your fish are building up fat reserves for the winter, when they go into semi-hibernation. In preparation for winter, their metabolism slows down. As such, they cannot digest high protein food. Pond owners should switch to a fish food that is low in protein and high in fiber. Feed your fish when the water temperature is between 60 and 42 degrees.
To safely keep fish in your pond over the winter it is important that there is a hole in the ice. Otherwise, toxic gases from decaying fish waste and leaves will build-up under the ice and potentially kill your fish. You should never break a hole in the ice with a pick because the shockwaves can easily kill your fish. Your pond should be equipped with a de-icer, a bubbler or small pump to preclude it from completely icing over. If your pond should freeze pore boiling water on the ice until a hole is melted.
While you should operate a small pump or bubbler in your pond over the winter to preclude freezing and the build-up of gases, the pump that you use to circulate the water during the warm weather should be removed to avoid damaging the rubber or plastic seals. Many manufacturers recommend storing it in a bucket of water in a frost-free area. Likewise, ultraviolet lights should be brought in doors. Biological filters may stay outside.
Leaves accumulating in the pond may create toxic conditions for your water plants and fish. Therefore, cover your pond with a net that will catch the leaves.
Just as you cut back your perennials in the garden, you need to cut back your water plants by ¾’s. Plants that are marginally hardy, such as water lilies, should be moved to the deepest section of the pond. Tropical plants should be moved indoors.
Finally, you may want to add some winter hardy bacteria to the water. These beneficial bacteria ensure the water has biological activity even when the water temperature is below 55 degrees. This helps your fish maintain a healthy immune system. It also helps reduce the buildup of dead leaves and organic sediment over the winter.
Looking at Naked Trees
Soon the trees will drop their leaves. While I love the fall colors, and the first hint of green on the trees in the spring makes me giddy, I must admit I enjoy looking at the naked shape of the trees in the winter. Trees, especially during the winter months, are nature’s sculptures. During the warmer seasons we are frequently distracted from looking at their artistic shapes and interesting bark by their colorful leaves and flowers. However, leaves and flowers are superficial and fleeting. Not to take notice of a tree’s form is to ignore the essence of its being.
Children usually draw trees in one of two ways; either as a Christmas tree pyramid or a lollipop with a round ball on top of a stick trunk. While some trees do indeed have these shapes, trees come in a wide variety of shapes.
Tree shapes have been categorized into seven basic groups. They are: fastigiated, columnar, spreading, rounded, pyramidal, weeping, and picturesque. A tree’s silhouette is an important consideration when designing a landscape. It can influence the garden’s sense of unity, act as a background, or draw the viewer’s attention. As such, provided below is a short discussion on each of the seven shapes and some tips on how to use them to create an attractive landscape.
Fastigiated trees are tall and thin, tapering to a point at the top. Examples of fastigiated trees are Lombardy poplar (Populus italica nigra), American arborvitae (Thuja occidentalis), and Italian cypress (Cupressus sempervirens). I especially like the fastigiated beech called Fagus sylvatica ‘Dawyck’, which can grow to 80 feet tall while staying a slim 10 feet wide. Because they are so tall and thin, fastigiated plants cause the eye to look upward. Many classical Italian gardens have tall hedges of cypress that make a very dramatic impression, giving the landscape a feeling of tremendous height. When used singularly fastigiated trees act as exclamation points in the landscape, drawing attention, much as does a tall building in the skyline. Because their height commands such attention, great thought should be given to their use in the landscape. Avoid using them randomly throughout a design, as doing so will create too many focal points.
Columnar trees are tall and thin like fastigiated trees, but they are rounded at the top. Examples of columnar trees are sentry maple (Acer saccarum monumentale) and Hicks yew (Taxus media hicksi). Columnar trees are used the same way as fastigiated trees in the landscape.
The homeowner should be aware that many types of fastigiated and columnar trees (such as the fastigiated beech and columnar maple) are difficult to find and expensive. Better garden centers should be able to special order them for you if they don’t have them in stock, but be prepared to wait several month or a year before you get your tree. Nevertheless, don’t let the price or the wait stop you from using these trees. The right tree in a landscape can turn a ho-hum design into something spectacular. These trees can be absolutely stunning if used properly. They are well worth the investment.
A tree with a spreading form is as broad as it is tall. Kousa dogwood (Cornus kousa) and flowering dogwood (Cornus florida) are excellent examples of a spreading tree form. Make sure you leave plenty of room for these trees to spread out as they mature. Just as fastigiated and columnar trees make your eye look up, the width of spreading trees make your eye look along the horizontal plane. They are great used in flat locations and across long horizons. Planted next to low horizontal buildings, they visually extend the low horizontal architecture of the building. The old saying opposites attract holds true in design, making the spreading form an attractive compliment to the fastigiated or columnar form.
A round tree is typified by a child’s drawing of a round lollipop tree on a skinny trunk. Many Japanese maples (Acer palmatum) have this form. This plant form is among the most commonly found. Round trees don’t cause the eye to look in any particular direction. As such, they are considered neutral, and are a good plant to use repetitively in the landscape to give a sense of unity. They also don’t detract from more dramatic plant forms, such as fastigiated.
Many individuals clip all sorts of trees into little round ball shapes despite the tree’s natural habit. Admittedly, sometimes this can be attractive. However, as a horticulturist and obsessive tree lover, I would be renege if I didn’t point out that this is bad for the trees. Unless the trees are continuously pruned in this manner they will grow witch’s brooms, long week branches, which easily break. The tree will never regain its natural shape. If you want a round tree select a tree with a naturally round shape. Don’t prune your trees into little round meatballs.
The pyramidal plant form is the basic Christmas tree shape, a cone. While many evergreens, such as pines (Pinus species) and spruce (Picea species - Picea glauca, Picea pungens, Picea pungens), have this shape there are deciduous trees (trees that loose their leaves) with this shape too. Sweet gum (Liquidamber styraciflua) and katsura (Cercidiphyllum japonicum) are two examples of pyramidal deciduous trees. They are effective as a compliment to rounded or spreading forms. Their cone shape resembles mountains. As such, they are attractive in mountainous terrain.
Weeping plants have a downward-arching shape, similar to that of an umbrella. Some examples of weeping plants are the weeping willow (Salix babylonica), weeping beech (Fagus sylvatica pendula), and weeping Higan cherry (Prunus subhirtella pendula). While I love this shape, surprisingly I have had many individuals tell me they don’t care for it. Their downward shape leads the eye to look toward the ground. As such, I have found them effective planted on upward slopes whose height you want to minimize. They are perfect along the edge of a body of water, where their graceful form accentuates the fluidness of the water.
The picturesque category is used for plants with unique shapes. This would include plants that grew in unusual shapes due to excessive winds, gnarled trees, and contorted unusual shapes. While most plants in this category may be one of a kind specimens formed by unusual conditions in nature, there are a handful of cultivars that this category applies to, such as Harry Lauder’s walking stick (Corylus avellanda ‘Contorta’). Bonsai plants are examples of plants that humans have forced to grow into picturesque shapes. Attempting to meet the consumers demand for the unusual, growers have developed varieties of contorted evergreens as well.
Winter is perhaps the best time to select a tree for your garden or landscape. Without the attention grabbing leaves and flowers it is easier to study a tree’s form. Compare the seven forms and determine which shape(s) will look best in your garden. Then select a tree species that has that form and will thrive in your environment (temperature zone, soil conditions, etc…). Once you decide upon the species of tree you want take the time to carefully select the specific tree that you will plant. While all trees of a given species may have the same basic shape, each tree is an individual. The shape of one individual may be more or less attractive than that of another. In addition, care should be taken not to select a tree whose branches cross over each other, as those branches are more likely to break during strong winds and heavy snow falls.
If you never paid attention to the shape of trees before, please take the time to do so this winter. They are beautiful. Enjoy nature’s sculpture.
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