ORNAMENTAL TREES THE BACKBONE OF LANDSCAPE

BY EVE KEENER

U.C. Cooperative Extension, El Dorado County Master Gardeners

Publication Date: September 3, 2004

In landscape architecture, ornamental trees are the most important and costly element. As the backbone of the garden, they must be selected based upon careful analysis of needs, the site, and the climate zone. Mistakes to avoid are planting trees that, when mature, will damage nearby structures or paved areas, encroach into septic systems or will be disfigured by too extreme temperatures. Further, consider whether the tree is for summer shade only (a deciduous tree) or an evergreen to hide some unattractive feature.

Another consideration is irrigation. All young trees need supplemental summer water for a few years, but some can withstand summer drought as they mature, while others will always need summer water, and should be planted within landscapes that will receive regular irrigation.

Lot size has a big impact on tree selection. Large landscape trees, e.g. pines, cedars, redwoods, sycamores, oaks, etc. should be selected only for large sites where they can be allowed to grow to their maximum potential without disturbance. Small and medium size trees, such as acacia, arbutus, birch, laburnum, small magnolias and the flowering cousins of fruit trees, are best for smaller lots where their size is proportional to the landscape. Close to patios, it is important to select trees without surface roots or messy fruit, such as Japanese maples, flowering dogwood, smoke tree, crape myrtle and Chinese tallow.

Begin landscape planning with a list of desirable trees for specific sites. Note such attributes as evergreen or deciduous, climate zones, flowering and/or fruiting species and seasonal leaf color and winter bark interest. From this list choose two or three kinds of trees which you think best fit your requirements—then visit your local nursery. If fall color is an important consideration, purchase your trees during fall color season. Fall or winter are the best times to plant young trees in any case.

There are many gardening books to help with this process. One recommendation is the Sunset Western Garden Book because its climate zones are specific for our location. However, any good landscaping book will have tree selections with growth information.

When you select your trees, it is best not to buy the tallest tree with the biggest trunk. Rather, find trees that are smaller but vigorous. These youngsters will quickly catch up to larger, possibly root bound, container grown trees. Another plus of the smaller tree is it will seldom need staking. If you buy a staked tree, remove the nursery stake when planting the tree since its purpose is only to protect the tree during shipping. If left on it will weaken the trunk. It is best to stake the tree at all, but allow it to move in the breeze to gain natural strength in its trunk. If it must be staked, follow the directions in any good gardening book that recommends using the two-stake method and make sure the stakes are no higher than are needed and are removed as soon as the trunk is strong enough to support its foliage.