Q. How do you plant an oak tree acorn?Lisa Davis, San Luis Obispo
A. The majestic oak, with all of its symbolic associations, is a beauty to behold, a place under which to contemplate life. It’s also a dwindling resource. Planting one of your own will be a long-lived aesthetic treasure, as well as a place for flora and fauna to congregate. The process is relatively simple. It is best to choose acorns from oaks that are established in your specific locale. Oak trees have specific adaptations that help them cope with a particular landscape.
The most viable acorns are still on the tree. Collect those that are turning from green to brown. If the acorn is deep green and the cap is difficult to detach, it is not ready. The largest are generally the best. Test acorns by soaking them in water for 24 hours. Those that float should be discarded.
To store acorns, take the caps off and place in the refrigerator. If stored properly, they can keep for up to six months. Place them in peat or sawdust with polyethylene bags (a thickness of 4 to 10 mils is ideal) in an area that is around 40 degrees Fahrenheit.
Before planting, float the acorns again. Keep only sinkers. It is wise to consider the optimal planting spot. Select an area that has well-drained soil and is not prone to weeds. Make certain that the tree is far enough from utility lines.
Gophers, mice and squirrels have a predilection for acorns and young trees. Placing a wire cage below and rising above ground may be warranted to fend off pesky predators.
November to March, during the rainy season, is the best planting time. Dig a hole several inches deep and about 10 inches in diameter. Loosen soil. Place a gram of nitrogen fertilizer in the hole, cover, and leave a three-inch depression on the top. Plant up to 10 acorns in this area. Tips should be down or sideways and caps should be removed. Cover with soil. Thin seedlings. By the third year, one strong seedling should be remaining.
Unless it rains, watering will be necessary. Water thoroughly after planting. Watering may only be necessary two to three times a year. However, in dry, sandy areas, watering may be as often as weekly. Always water deeply to promote root development.
Weeds and other plants should be cleared by at least two to three feet around the planting area. Mulch is beneficial to keep weeds at bay.