Landscaping After the Flood

Individually and as a community we are coming to terms with rebuilding our homes and landscapes after the storm damage, and I am beginning to receive questions from concerned citizens about the effects of flooding on their home landscape. There are some signs of plant decline I’ll review, and patience is key as we continue to recover.

There are many factors that can affect a plants’ long and short-term health. The primary limiting factor is inadequate oxygen exchange in saturated soils. The roots of all plants need access to oxygen in the soil. When soils are saturated, an anaerobic environment is created where plant roots are not getting proper oxygenation. There are not many options to help perennial plants except to watch for signs of stress after the event. Symptoms can include yellowing or browning of leaves, leaf curling or wilting, reduced new leaf size, complete defoliation or branch/stem die-back. Plants that are fully submerged for extended periods may rapidly decline. Mostly with trees, we may see cases that include gradual plant decline and death over several years.

There is good news: most native trees, shrubs, perennial plants and grasses can survive through two weeks partially submerged in floodwater. Established and healthy trees and shrubs will be more flood tolerant than stressed or young trees. Unless there is a very thick deposit of sediment, our lawns fair well after flooding events and general maintenance should be practiced as the season progresses. I would like to offer advice to help you maintain your landscape after the floods.

Before tilling the soil to restore landscape features, ensure that the soil is dry enough to work to prevent compaction. After the water recedes, remove silt that exceeds 4-inches around woody species (trees and shrubs) in your landscape. Reference my comment to support atmospheric oxygen exchange into the soil to encourage root growth. Conversely, cover exposed roots and fill any low spots in your landscape chiseled out by flood waters. Even though we had an exceptional event, now is the time to reassess landscape features to regrade and provide appropriate drainage features.

Suppress the urge to immediately fertilize your landscape plants. One of the best investments for plant health is to have your soil tested to determine any nutrient deficiency. You can browse online to the Texas A&M AgriLife Extension’s Soil, Water and Forage Testing Laboratory to download forms that include fees and instructions to have your soil tested: You can also stop by our Brazoria County AgriLife office in Angleton to get a copy of the forms. Once you get your test results back, I will assist in deciphering the results for advice on landscape fertilization maintenance. Maintain your lawns with annual and regular fall fertilization, about 1 pound of nitrogen per 1,000 square feet and applied around mid-October. You can mulch your landscape beds, and be sure to use aged and chipped hardwood mulch available from your local hardware or feed store. Don’t forget to flush your sprinkler system to avoid any repair issues from clogged pipes. With a little bit of patience, observation and appropriate action, you will find that your landscape is as resilient as our communities.

You can find out more about our gardening programs from our website: Don’t forget that we host a Call Center every Wednesday morning at the AgriLife office from 9 am to noon to answer your garden questions. I invite you to share your ideas and successes in your garden by browsing online to my Facebook webpage: See you in the garden!

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