After a brief dry spell in early July we are finally getting some much needed rain, but are we getting TOO MUCH rain?!!
Many of our customers are asking “What effect will all this rain have on my landscape?”
Heavy rains, especially over an extended period of time can place a lot of stress on turf and other landscape plants. When coupled with high humidity and compacted clay soils common in this area, this stress can lead to some significant issues.
Plants need water, right? ……so what’s the issue with too much rain?
All soils are made up of particles. The space between particles hold both air and water. Plants draw oxygen from these air pockets via the root system. When it rains water fills these spaces and the air is displaced. As gravity draws water down into the bedrock the air returns. This cycle is repeated over and over throughout the growing season. Obviously, sandy soils drain much more quickly than heavier, clay soils. If these air spaces are kept filled with water over an extended period the roots will be deprived of the oxygen they need. If this condition persists roots stop functioning properly and will begin to die. At this point, root systems also become more vulnerable to fungus issues such as Phytopthora Root Rot. Newly planted trees and shrubs are the most susceptible.
Foliage of various plants will be effected not so much by rain but by the accompanying humidity. Some common foliar diseases that favor excessive wet weather include Anthracnose (Dogwoods, Sycamore), Powdery Mildew (Lillacs, Phlox, Peonies), Rust (Crabapple, Pear) and Shot Hole Fungus (Cherry Laurel, Cherry). The weakened root systems can also lead to chlorosis, which is a decreased ability to process Iron. All of these conditions often lead to some defoliation.
Most grasses can tolerate being submerged for extended periods without permanent damage. Once the flooded area has dried out, lightly rake out any piles of debris and silt. Just like landscape plants, turf is likely to be more effected by the associated high humidity than standing water. Some diseases effecting turf grasses during periods of excessive wet weather include Brown Patch, Pythium blight and Dollar Spot. You may also notice an increase in Mushrooms and summer weeds such as Nutsedge and Crabgrass.
The moist soil can also lead to an increase in Grub activity and the stressed turf will also be more susceptible to Sod Webworms & Chinch Bugs. We will be monitoring and treating for these issues moving forward. If you haven’t had your lawn Core Aerated in a while this is definitely the year to sign up for this very beneficial service!