Once you've gathered (and sampled!) acorn harvests for a season or two, you might want to plant a food tree in your own yard. By propagating local stock, you'll be able to grow varieties that are well suited to your soil and climate and that may be difficult to purchase.
The first step in planting an oak is to selectlarge, well-formed, healthy acorns from yourfavorite parent tree. Experience in gathering the nuts for eating will help you in thisrespect, as you'll be able to recognize a suitable seed simply by its sheen, color, and feel.Discard any acorns that sport worm holesor are discolored, and remove the caps fromgood nuts soon after you harvest them.
Fall is the preferred time for planting acorns, as many cold-climate oaks require a stratification period — that is, the nuts must remain at temperatures just above freezing for at least six weeks, and perhaps as long as 20 weeks, in order for the nuts to germinate. However, if you intend to store the seeds for planting at a later date, you can stratify them yourself: Set the kernels in a moist planting medium such as sand, peat moss, vermiculite, or sawdust and place them in cold storage. The acornsofthe white oaks are generally viable for a month or two after ripening, while thoseofthe black oaks are viable for six months or more. Drying the acorns to 60%oftheir initial fresh weight and then keeping them in cold storage (35-40°F) can lengthen the viability of white oak acorns to about eight months, and similar treatment might further extend the viability of black oak acorns, as well.
Once you've collected your acorns, or received a supplyofnuts from oneofthe firms listed in the accompanying editor's note, you'll need to decide on a propagation method.
Chances are that your acorn cache will be limited, so you'll probably want to grow seedlings in seedbeds, flats, or containers before setting them out in their permanent location. You can even germinate the acorns before planting them in their "nursery" area. To do so , place the nuts about 1 " deep in a plas tic bag filled with moist, sterilized potting medium and store the package at 50-75°F. The acorns should sprout in a few weeks. When the sprouting root is 2-3° long, transfer the tiny tree to a deeper container or seedbed.
- Seedbeds. Planting acorns in seedbeds is quite easy, especially if the timingofthe seedlings' growth allows them to be transplanted directly into their permanent ground. This propagation method is not recommended for evergreen oaks, but it works fine for deciduous species.
- Flats. Growing the seedlings in flats is more labor-intensive than seedbed planting because the small trees must be transplanted more frequently so that the roots don't become tangled. Use flats that measure 4" deep or more; if possible, they should have screen bottoms to allow for adequate drainage and to encourage air-pruningofthe roots.
- Containers. Starting your acorns in containers is a good methodofpropagation if you plan on growing only a few trees. A pot at least 2" X 2" X 8" deep is required (gallon vessels work well and are easy to locate). Trees intended for arid areas should be grown in even deeper containers to encourage taproot growth.
The seedlings should be transferred to larger pots before they become root-bound. Because the roots typically grow much faster than the stem, this problem may occur before a great dealofaboveground growth is apparent, so keep close tabs on the progressofyour seedlings. And, as when transplanting any crops, gradually hardenoffthe plants before the move and minimize the shockoftransplanting by setting the repotted plants in a partially shaded location and by keeping them moist.
Transferring the seedlings to their permanent home should be done when conditions favor growth. Spring is usually an ideal time, but if the autumn rainfall is more reliable in your area, you might opt to plant your young trees in the early fall. Again, hardenoffthe seedlings by reducing water and nutrients and gradually exposing them to outdoor conditions. Supplemental watering during the first year or two will ease your trees' adjustment to their new home
HOW THEY'LL BEAR
Acorn production begins three years afterplanting for some oaks, and may take considerablylonger for others. As with pecansand other nut crops, acorn yields often vary from year to year. This adaptation, knownas predatory sanitation, enables trees to produce extremely high yields in boom years(thus ensuring that enough acorns will surviverodent and insect losses), while the lowyields in bust years reduce the insect populationsand contribute to the decline of otherpredators, as well.
Insects, fungal diseases, and pollutants can substantially reduce acorn yields. Although pesticides are sometimes used to combat infestations, especially in urban areas, many diseases can be eradicated only by destroying the infected tree. For that reason, prevention is by far the best policy. To promote tree vigor, match oak species with their preferred habitat ...make certain that sufficient water, nutrients, sunlight, and space are available ...avoid accidental injury to the tree (such as cuts, bruises, or broken limbs) ...encourage natural insect and disease controls as much as possible ...and remove and destroy fallen fruit and prune dead or infected limbs from your trees. In the event that chemical controls do become necessary, check with your state's forestry department or with the nearest office of the U.S. Department of Agriculture Forest Service for information.
A Forager's Guide to Acorns
Ballota Oak(Quercus ilex var. rotundifolia): A medium-size evergreen oak from southwestern Europe and northern Africa with large, edible acorns that take two years to mature.
Bur Oak(Q. macrocarpa): A medium-size, drought-resistant deciduous tree found in the mideastern U.S., Canada, and south to Texas. This slow-grower prefers limestone soils and is used commercially for its wood. The 2" acorns mature in one season, and an acorn-producing cultivar, Q.m. Ashworth, is available commercially.
Chestnut Oak(Q. prinus): A medium-size tree of the eastern U.S. that's tolerant of a wide range of soils and sites. This slow-grower produces quality wood and 1" to 1-1/2" acorns that mature in one season.
Chinquapin Oak(Q. muehlenbergii ): A widely distributed medium-size deciduous tree of the Midwest and eastern U.S. that prefers alkaline soil. The chinquapin grows rapidly, has very durable wood, and produces 1" acorns in one season.
Dwarf Chinquapin Oak(Q. prinoides): A small tree or shrub of the eastern U.S. that's common to dry, rocky slopes. The 1" acorns mature in one season.
Emory Oak(Q. emoryi ): A small to medium-size tree of the southwestern U.S. Its sweet acorns take one year to mature.
Gambel Oak(Q. gambehi ): This small to medium-size tree is the most common oak of the Rockies. The sweet 1 " acorns, which mature in one season, were used extensively by the Indians.
Huckleberry Oak (Q. vaccinitfolia): A shrubby mountain evergreen found at elevations up to 10,000 feet in California's Sierra Nevada mountains. The small acorns mature in their second year.
Live Oak(Q. virginiana): A large, spreading evergreen oak found primarily in the southern states. This fast-growing species is tolerant of moist, sandy soils and produces very dense, durable wood. The 1" acorns mature in one season.
Mongolian Oak(Q. mongolica): A tall deciduous oak native to northeastern Asia. This important lumber tree has small, 3/4" acorns that mature in one season and are extremely sweet.
Swamp Chestnut Oak(Q. michauxii ): A medium-size tree of the southeastern U.S. that prefers moist locations. The very sweet acorns are about 1" in length and mature in one season.
Swamp White Oak(Q. bicolor): A medium-size deciduous tree that's found in the northeastern U.S. and west to Nebraska. It's tolerant of swampy conditions and grows rapidly, producing good wood that was once favored for barrels. The large (up to 4") acorns mature in one season.
Valley Oak(Q. lobata): This is the largest of the western oaks and is restricted to California. It's most common in rich bottomland but can be found up to 6,000 feet. The wood is of value only as firewood, but one tree may yield as much as a ton of 2" acorns in one year.
Valonia Oak(Q. aegilops): A semi-evergreen oak of the eastern Medoerranean. The acorn is reportedly sweet, and the cap was formerly harvested for its tannin.
White Oak(Q. alba): This medium to tall tree of the eastern U.S. tolerates a wide variety of conditions. It's an excellent tree for wood and a prolific producer of 3/4" acorns that mature in one season.
Black Oak(Q. velutina): This species favors dry soils and is hound primarily in the central and eastern U.S. Its acorns mature in two years.
California Live Oak(Q. agrifolia): An attractive evergreen tree of the California coast that produces firewood-quality wood and 1-3/4" acorns that ma cure in one season.
Cork Oak(Q. saber): These long-lived (to 500 years) evergreen trees are native to the Mediterranean, yet have done well from Maryland to California. The species is an attractive ornamental and produces cork at 10-to 20-year intervals. The acorns, which mature in one season, may be as large as 1-1/2".
Kellogg Oak(Q. kelloggii ): An attractive medium to large tree with a broad crown. This species tolerates a range of conditions from clay to gravelly soil. Its wood is of no value except as firewood, but the 1-3/4" acorns, which take two seasons to mature, were favored by the Indians. One tree may produce in excess of 1/2 ton of acorns a year.
Laurel Oak(Q. laurifolia): This rapidly growing medium-size tree of the South is shortlived (it matures in 50 years), but it produces heavily. The 1" acorns mature in their second season.
Northern Pin Oak or Jack Oak(Q. ellipsoidalis): A fast-growing medium-size tree of the Midwest that produces good wood for flooring and furniture. The 3/4" acorns mature in their second season.
Red Oak(Q. rubra): A fast-growing medium-size tree of the northeastern U.S. that does well on a variety of soils. It's used ornamentally here arid in Europe, and the 1" acorns mature in their second season.
Scarlet Oak (Q. coccinea): A rapidly growing deciduous tree of the north-central U.S. that's often used as an ornamental because of its bright red foliage. The 1" acorns take two years to mature.
Shumard Oak (Q. shumardii ): A southeastern deciduous oak that reaches up to 130' in height. The wood is valued for veneer, furniture, and flouring. The 1" acorns take two years to mature, and the tree produces a heavy crop every 2 to 4 years.
Water Oak (Q. nigra):This southeastern oak grows rapidly and is frequently grown as a street trey The 3/4" acorns mature in their second year.
Tanbark Oak (Lithocarpos densiflorus):This medium-size tree is native to California and Oregon and thrives in humid areas The sweet 3/4" acorns mature in two years.