Tree Horticulture Hints for Bath Garden Club Yearbook 2008-9

  • Select woody plants that are suitable for the site in soil type and moisture needs. Also consider the ultimate size and shape of the plant since these cannot be radically changed. (Berg, bulletn 2169)
  • Mycorrhizae, a group of underground fungi that have a symbiotic relationship with plant roots and increase their ability to extract water and nutrients from soil, are important in the survival of some tree species. Encourage mycorrhizae in new plantings by adding well rotted plant materials. Avoid fertilizers, over watering and soil compaction that can kill the fungi.
  • Pruning benefits trees. Start in late winter or early spring by removing overlapping and dead or diseased branches. Other techniques vary by species and may include thinning to admit sunlight and heading back branches to control size or improve shape. Never leave a stump; always cut just above a bud or joint collar. Whenever possible, prune trees when they are young, to direct future growth. This is far more effective than waiting until corrective pruning must be done. (Berg, bulletin 2169)
  • Avoid damaging the bark when mowing or trimming around trees because the thin cambium layer just under the bark is the only living part of the tree’s woody structure. Damage prevents water and nutrients from reaching branches, and also prevents sugars from moving into the roots.
  • The brilliant fall leaf colors develop as green chlorophyll fades due to shorter, cooler days, revealing the yellow carotenes (Vitamin A relatives). Red/purple anthrocyanin pigments similar to those in blueberries and cranberries are formed when warm sunny days and cool nights predominate. Oranges appear where yellow and red pigments are present. The dry brown of oak leaves is due to tannins.
  • Fallen leaves can be used as mulch or as a carbon source for your compost. Allowing leaves to remain in your landscape helps the soil retain valuable nutrients and reduces contributions to landfills.
  • A minimum of 100 square feet is needed for a mature forest tree. Following clear cut lumbering, about 8000 mixed seedlings may quickly sprout with the most suitable species eventually dominating each area. The commercial practice of replanting a single species tends to reduce wildlife habitat and the resistance to disease and insect pests (Heinrich 15).
  • Trees that are bent by ice or snow will frequently grow in an unsymmetrical pattern to compensate and right themselves. Trying to straighten them may cause breakage.
  • Heating by winter sun followed by very low temperatures at night can cause frost cracks in tree bark. Conifers are protected by branch shading. Deciduous trees with dark bark are protected by a rough surface with scales, ridges or plates. Smooth barked species like birch, aspen and beech have only their light reflective coloration for protection and are most susceptible to this damage (Wessels 83).
  • Trees in the community can reduce storm water run-off and soil erosion, thus protecting waterways from pollution and reducing road maintenance costs. They also muffle traffic noise and offer recreational opportunities and provide wildlife habitat (Parrish 2000, 6).
  • Tamarack (Larix laricina), also known as American larch or hackmatack, is the only needle-leaved New England tree to drop all its foliage in autumn. This is due to its weaker limbs as compared with spruce and fir. A large specimen can produce 20,000 small cones that provide food for small mammals (Fergus 262-267).
  • Red maple (Acer rubrum) exhibits beautiful coloration in all four seasons. Since it can withstand flooding, it is also called swamp maple. Its versatility extends to strong drought survival (Fergus 160-164).
  • Eastern hemlock (Tsuga canadensis) is the most shade tolerant of all eastern trees. In the forest understory, they grow slowly, waiting for the sun as upper story trees fall (Fergus 127- 133).
  • Root pruning by cutting in a staggered pattern with a spade a few inches inside the drip line can prepare a small tree or shrub for transplanting the next season. It may also be used to control growth or rejuvenate overgrown specimens.
  • Age of conifers can be estimated by counting the branch whorls which represent one year’s growth. Branches emerge from the circle of lateral buds just below the central leader bud at the apex of the tree.
  • The common native tree species of Maine number sixty-six. These comprise 14 conifers or softwoods and 52 hardwoods or broadleaf, deciduous species (Forest Service).
  • For advice about your trees, contact the Maine Forest Service, your county Office of the University of Maine Cooperative Extension (UMCE) or local agencies. Consult http://www.umext.maine.edu/onlinepubs for UMCE bulletins.

Works Cited

Fergus, Charles, Trees of New England: A Natural History, Globe Pequot Press, Guilford, CT 2005.
Heinrich, Bernd, The Trees in My Forest,Harper Collins, New York, 1997.
Maine Forest Service, Identifying Forest Trees of Maine, CD-ROM available http://www.maineforestservice.org, January 2004 edition.
Parrish, Christine, The Woods in Your Backyard: A Homeowner’s Guide, Maine Forest Service, 1999.
Parrish, Christine, What do trees have to do with it? A forestry guide for communities, Maine Forest Service, 2000.
Stack, Lois Berg, Pruning Woody Landscape Plants, UMCE Bulletin #2169, 12/10/07.
Wessels, Tom, Reading the Forested Landscape: A Natural History of New England, Countryman Press, Woodstock, VT 1997.

Acknowledgements

Thanks to the following for valuable corrections and additions to the horticulture hints:
Lois Berg Stack, Ph.D., Extension ornamental horticulture specialist, UMCE, Orono, Manie.
Nancy Coverstone, M.S. and Tori Lee Jackson, M.S., Extension Educators, Androscoggin-Sagadahoc Counties Office, UNCE.