How Does Excess Rain Affect the Landscape

 

Here in the southeast we have had steady rain this spring. In fact, it is one of the wettest on record. Due to the historic rainfall I have had several conversations with homeowners on what issues may occur, and what they should expect.

 

Disease and Weed Pressure

Over-watering of turf and landscape plants can promote disease and weed species to grow and flourish more then normal. There are always diseases and weeds present in the soil that can take advantage of the new conditions. 

Be prepared for new weeds to take advantage of the damp soils. Many weeds such as Smooth Crabgrass and Nutsedge prefer extended periods of wet conditions for their seeds to germinate in an existing lawn. Combinations of pre-emergent and post-emergent herbicides can be effective at removing these weeds from most turfs.

Fungi use the cool and wet conditions of spring to flourish and infect plants in the landscape. Look for signs of distressed turf over the next few weeks including browning or thinning turf in blotchy or circular patterns. Catching and treating diseases early can minimize the damage.

For an example of the fungus Zoysia Patch and how to fix it and other similar turf diseases please see this past post.

 

Standing Water

Standing water near the home can potentially cause damage to the infrastructure, and redirecting the water away from the foundation by using a swell or drain should be your first priority. It is recommend to use a high quality, insured, and reputable contractor that guarantees their work. 

 

Click here for more information on drainage systems.

 

Horticulturally speaking, standing water is also an issue when it pools around plants. 'Wet feet' is one of the top reasons for unexpected plant death in the landscape. Standing water kills plants in a variety of ways. Waterlogged soils can suffocate roots by limiting oxygen pockets in the soil. Wet soils can also cause fungal diseases to spread and infect plants whose natural defenses may be compromised due to the unfavorable conditions. 

If standing water is a regular concern in an area of your yard, and correcting the problem through redirection is not possible, it is recommended to select plants for the area that can tolerate wet conditions.  

 

Click here for plants that can tolerate wet conditions.

 

It may also be necessary to plant new trees and shrubs 2 to 4 inches higher than the surrounding soil, thereby creating a natural hill to drain water away from the root crown. This will help the plant resist large scale die back due to over-watering. The Clemson Extension service addresses how to properly plant trees and shrubs in more detail on their website. 

 

Erosion

Preventing erosion in the landscape is a combination of two factors: having enough fibrous plant roots in the ground to maintain the structure of the soil, and having physical barriers above ground to reduce the speed and force of the water runoff. Landscape designs with stones and plants help redirect the water away from narrow corridors. This therefore reduces the speed of the runoff. Ground cover plants can be utilized to aid in erosion by being both the physical barrier and the anchors for the soil.

Once established, ground cover plants should be in dense enough clusters to create a canopy that protects the soil from weather exposure. Almost any plant could feasibly be a ground cover, but there are many that are considered ideal for the landscape. This includes many low growing options for sunny and shady locations.

 

By: Jonathan L Holmes