The northeastern part of the state has experienced persistent annual flooding for the past few years. This flooding is a long term event that has cost many farmers their land and crops, and others their homes. Unlike the Missouri River flooding, the floodwaters in the northeast will not recede with reduced outflows from dams. The best way to mitigate the long term effects of the saturated soil on tree growth is to think above the ground.
Planting trees on berms is one solution. Berms are simply raised shaped mounded hills of soil placed in the landscape. Berm depth can vary from eight to twenty inches, and usually curved to some degree giving it a more natural appearance. The slope of the berm should be gradual; they should be mulched to keep erosion down and to keep from drying out.
Other ways to mitigate poorly drained sites it to plant the trees on top of the ground and not bother digging a planting hole.
- Cut out the sod and place the tree on top of the ground. This works for bare root, potted or balled and burlap plant material.
- Build up the soil beside the root ball to prevent the roots from drying out.
- Gradually slope the soil out to meet the lawn area. The tree will need to be staked for at least one year.
- To help the roots stay moist, place a three inch layer of mulch over the top of the soil. Be sure to leave a gap between the mulch and the trunk of the tree to prevent trunk rot and facilitate oxygen absorption.
- Lawn edging of the berm will finish off the site.
Taking either of these planting steps will help your trees survive in an area with saturated soils.