Regenerating Oaks in Missouri's Bottomlands
will also improve soil drainage, aeration and conditions for good root growth. Mounding is most beneficial when planting trees in poorly drained, clay-rich soils. Coarse, well-drained soils probably do not need to be mounded.
Oak from acorns
Landowners can also sow acorns to regenerate bottomland oaks. Acorns collected from local bottomland oak trees are best because they produce seedlings that are adapted to life in the floodplain. Burying them in the top several inches of soil keeps acorns from drying out, ensures a good environment for germination and reduces acorn loss to small mammals.
Seedlings that develop their roots in place may do as well or better than seedlings that have been transplanted from a nursery. However, acorns may be eaten or destroyed by a host of insects, diseases and animals. After germination, small seedlings are subject to intense competition from other plants, floods and animal browsing. During early shoot growth, oak seedlings use most of their energy to build a root system rather than grow tall. Regenerating oaks by seed usually requires sowing thousands of acorns per acre to get the desired number of mature trees.
State and private tree nurseries usually sell bare root seedlings. These are mechanically lifted from the soil after one or two years of growth, packed into bundles and shipped to planting sites. Bare root seedlings lose much of their root system and experience stress during this process. Recovering from this shock and injury after planting requires time and energy, which puts them at a disadvantage with competing vegetation. Because the survival rate of bare root seedlings is lower, landowners should plant extra trees to obtain the desired number of oaks. Again, the larger the seedling, the better its chances of survival.
Large, container-grown hardwood seedlings recently have become available in Missouri. These seedlings are grown in 3- and 5-gallon plastic pots in a way that creates a dense, fibrous root system. Trees may be 5 feet tall or more after one to two years growth in the nursery. Container grown trees experience less stress after planting than bare root seedlings because their root systems remain intact and are ready to expand into the soil when conditions are right.
Another advantage of large container stock is that some trees produce acorns at a very early age. In some plantings, 2-year-old swamp white oaks and 5-year-old pin oak seedlings have produced acorns. This food production helps turkey, deer, ducks, songbirds and mammals. Although the initial cost of planting large container stock is higher than planting bare root seedlings or directly seeding acorns, their survival and growth rates are higher.
Your schedule, budget and equipment will dictate your strategy for regenerating bottomland oaks. Whether you sow acorns or plant seedlings, you can improve survival rates by reducing competition from other plants and damage by animals.
Your efforts will be rewarded in a more diverse, native bottomland forest that offers better habitat for wildlife and improved timber production.