When floodwaters come calling

Posted August 15, 2013 at 10:29 am


by Guest Author Vickie Baumer

The flooding rains of these last few weeks has certainly been wonderful for recharging the underground aquifers and growing area pastures for livestock, but if you are a gardener, the large amounts of rainfall can be difficult to deal with on a variety of levels. Rain may have washed away soil, mulch, plants and seeds. The pounding deluge may have caused soil compaction making it more difficult for roots to breathe; washed away nutrients and deposited mud on rain flattened plants. In addition, when flood waters have covered your property, contamination from backed up creeks and rivers or even overflowing septic systems is another concern.

If that is a scenario you are experiencing, don’t eat produce from your garden unless you can boil, peel or thoroughly wash the produce. University of Wisconsin Extension has more information on this topic: http://hort.uwex.edu/articles/safely-using-produce-flooded-gardens.

You may be wondering what do you do then to overcome all the rain and how do you salvage your garden? If you are blessed with good drainage in your garden, the main thing is to wait for the rains to pass and try not to work the soil or walk on it until there has been some drying in order to avoid further compaction. While waiting for things to dry out, prop up, wash off mud and trim broken branches of flattened plants, and replace mulch on ornamentals and trees that may have floated away. This is also a good time to note where the wet spots in your landscape are located for future planning.

If you have poorly drained areas in your garden try and determine how to improve drainage for the future. Consider raised beds, incorporating organic matter to improve drainage in your soil, carving out channels to carry away excess rain, diverting gutter down spouts from your garden beds or aerating your lawn areas to facilitate drainage. Examine the plant choices that have been made for your landscape. The best choice for frequently flooded areas may be plants that can do well in flooded conditions like River Birches, Redbuds, Summersweet, Ninebark and Daylilies or consider developing a rain garden. There is a good example of a rain garden at the Fruit Experiment Station Arboretum – come by and take a look and see if that might be an idea for your garden.

With all of the rain and warm temperatures, breeding conditions are perfect for fungal organisms and insect pests. Do all that you can to improve air movement in your garden so the fruit, vegetables and foliage will dry quickly. This will reduce the possibility of fungal organisms having a place to grow. Remember to remove any diseased fruit or vegetables and take them out of the planting area.

The general consensus is that most ornamental trees and shrubs can tolerate about a week of flooded soils but the longer oxygen is denied to the roots, the greater the chances of root die back. Above ground symptoms of root damage will include leaf yellowing, drooping and curling leaves, early fall color, leaf drop and even branch die back. Don’t be too quick to remove leafless branches as dormant buds may still push fresh leaves out this season.

Time will tell as to the full effect of last year’s season of drought and now this year’s season of flooding. Much will depend on what future weather stresses are ahead and how that will affect our landscapes. The best strategy is to keep plants in as healthy a condition as possible, free of diseases and insects, and their chances of survival are much greater whatever weather comes our way.

Direct comments or questions concerning this column to Marilyn Odneal via email at MarilynOdneal@missouristate.edu; write to Missouri State Fruit Experiment Station, 9740 Red Spring Road, Mountain Grove, Mo. 65711; or call (417) 547-7500. Visit our Web site at http://mtngrv.missouristate.edu.

Flood waters in the garden 2 cc.tif

FLOODWATERS IN THE GARDEN – This clump of river birches can tolerate some standing water. Most ornamental trees and shrubs can tolerate about a week of flooded soils but the longer oxygen is denied to the roots, the greater the chances of root die back.