By Kimberly Hovet
Poplar trees are hardwood trees that produce
their own rooting hormones, and can be tested by placing a twig in water
to see if it sprouts roots. One warning to those of you thinking about
planting a poplar, do not plant one within 100 feet of a building. The
roots go wandering, looking for water and can end up plugging sewer lines
and other underground pipes.
Poplar trees are planted as cuttings using
8 to 10 segments of one-year old stems. This process is called vegetative
propagation and is one way to ensure continuity of the genetic makeup of
desired clones. Producing your own cuttings is great way to save money
and ensure that you have quality stock year after year. It does, however,
require a fair amount of manual labor and storage space.
A poplar nursery, also called a clonal
orchard or cutting orchard, should be established on a fertile, well-drained
site. Spacing is an important consideration. As a guideline, cuttings can
be planted in rows with approximately 39 inches apart and approximately
39 inches apart within each row. The exact spacing will depend somewhat
on the size of the equipment you plan to use. Spacing has little effect
on the diameter of cuttings. However, if the stools are planted too close,
they will compete with each other for nutrients and light and eventually
will die.
These nurseries require annual maintenance.
Every winter when the trees are dormant the stool beds must be cut back
to about 4 inches above the ground. The first time the trees are cut back,
they usually consist of a single stem or whip. The spring after this single
whip is removed, several new sprouts will arise from the remaining 4inch
stump. This is called coppicing. If the stems are cut too close to the
ground, the subsequent sprouts may grow prostrate or very close to the
ground and be difficult to work with.
After whips have been harvested, they can
be brought inside. Remove and discard any branches and cut the whips into
8 to 10 inch segments. If a dry spring is expected, longer cuttings are
recommended. The longer cuttings will provide an extra bit of insurance
in the event of drought conditions. If the soil is shallow, shorter cuttings
are recommended.
After the cuttings are done they should be bundled so that the buds are all pointing in the same direction. While in storage, the cuttings must not lose moisture and dry out. This can lead to black stem and will cause death. To prevent this, double wrap all the cuttings in plastic, or store them in a humidity controlled environment. Cuttings should be stored at or below freezing until they are to be soaked for planting.