Heritage trees have stories to tell. Their branch structure speaks volumes about their history: the winter storms of past years, periods of drought, soil depth and fertility and especially the thoughtfulness of those who understood what eventual spread really meant.
Recently, I had the breathtaking experience of observing an old English walnut silhouetted against the setting November sun. This venerable tree has been growing in a special location for more than 100 years. How many travelers along the old road from Colfax to Grass Valley have taken note of it?
With ample space to spread to its full potential, this heritage tree graces a gentle slope with its immense branches. If it has ever been pruned, it is not apparent. The strength and spread of its lower branches is greater than any other walnut I have seen in the foothills.
The walnuts on my property, originally planted over 100 years ago, were planted too closely. One was even planted a few feet from an old barn. Three of the trees grew unbalanced and eventually succumbed to winter damage.
Information is available about the eventual height and spread of trees. Knowing whether the mature form is upright or spreading also guides decisions. “The Western Garden Book” gives enough detail to make wise decisions when it comes to tree selection. Trees should be appropriate to the space.
Historically, trees have been planted to shade homes and gardens. On Broad Street in Nevada City, a linden has been attracting photographers these past few weeks as it transitions to autumn gold. On my way to a nearby landscape one morning, I could not resist parking to catch a shot. The linden was glowing in the early morning fall sun.
Before power lines were a consideration, the eventual size of a shade tree could be quite grand. Lindens have a long history in European gardens, so it comes as no surprise to find them introduced in American gardens by early settlers.
With the vast array of choices we now have in nurseries, there seems to be a tree perfect for any situation. While the walnut needs so much space it is suited to rural acreage, the linden needs open space to achieve its mature height, and will do so without infringing on the sidewalk past the Victorian home it graces. The beautiful weeping cherry tree is not a large tree, but it needs ample space to grow. Planted too close to walkways, pruning becomes necessary, which definitely damages the dramatic form.
Smaller trees are more appropriate where space is limited. My favorites include the paperbark maple (Acer griseum) and the many species of hawthorn (Crataegus). Japanese maple (Acer japonica) has many cultivars suitable for a smaller garden. The species Japanese maple is one of the larger, a very vigorous tree with good fall color. It can be trained to grow out of reach of deer.
Pruning and training a tree when it is young shapes its future. It may not be necessary if you find a specimen that is perfectly branched. Certainly the first year, minimal pruning is best. Let the tree grow, then evaluate its branching habit. Do not prune unless it serves a purpose.
Buds are directional. When you prune to a bud with a heading cut, the bud will likely begin a new section of branch. By studying the buds after winter damage, you can usually redirect the growth. A heading cut prunes the branch along its length. A thinning cut removes the branch (large or small) back to its point of origin.
Heading cuts stimulate growth of all buds below the pruning cut, while a thinning cut may eliminate growth in that section of the tree unless a bud remains. Imagine the tree as a mature specimen and prune only as needed, shaping its future for many generations to come.
Carolyn Singer has gardened organically in Nevada County since 1977. For information, visit www.carolynsingergardens.com.