Is Flooding Ruining Your Lawn?

Is Flooding Ruining Your Lawn?

I want to send our thoughts and prayers to everyone devastated by the recent Indiana floods. For far too many, there are much bigger concerns than landscaping and lawns.

Last month, you know, before all the rain, we had Berger Hargis install French Drains in our yard. If you do not know what French Drains are, read this: What is this French Drain You Speak of? The bottom line is that French Drains are perforated pipes buried below your lawn that collect and redirect excess water.

We had them put in our backyard several years ago. Before the drains, the yard would flood with several inches of water. We had to redirect the flood or plant rice. The new drains are in a side yard that used to stay full of water. The drain also includes all of our downspouts. It. Works. Great!

But What Does Excess Water Do to a Yard?

As we now know, our timing on the drain installation was perfect. However, with so much rain, we still got a lot of water. And the bad news is that flooding can cause long-term damage to your lawns. Especially when water sits on your grass surface for several days.

Why, you may ask? It is simple: the lack of oxygen, light, and nutrients can wreck your yard. Silt swept in by heavy floodwaters does not help either.

The Damage

Root suffocation -- Grass roots need oxygen to survive. Flooding drowns your grass, causing root rot and more.

Too hot -- You know how cold rain and snow damage grass. Warm water does too by stressing stems, blades, and roots.

Low or no light -- It is hard for your grass to photosynthesize without sunlight.

Soil compaction -- Floodwater is heavier than you might think. It compacts soil, making drainage even more difficult and further limiting root growth.

Silt and sediment -- Floods carry dirt, sand, and dead organic matter, smothering your grass.

Contaminants -- Would you drink flood water right out of your yard? That is what your grass is doing. Who knows what it carries: petroleum, viruses, pesticides, or more.

What to Look For

Puddles or silt layers. Brown grass. Yellowing blades. Moss flourishing where it has not before.

What Makes it Worse?

The longer it sits, the worse it can become, and the same for the depth of the water. Deep is not good. Keep in mind that not all grass types are flood-tolerant, like bermudagrass. Finally, if your lawn has already had problems, flooding will only make it worse.

How To Make it Better

Remove all the silt and debris as soon as you can.

Aeration after the flood can improve your lawn in several ways. See: What Is Lawn Aeration and How Do You Know If Your Lawn Needs It?

Even if you have fertilized before, the water may have washed it away, so it is good to test your soil and then fertilize appropriately.

If the flooding was four days or less, it could recover without re-seeding or re-sodding. However, for longer floods this may be necessary.

Keep an eye out for weeds and diseases. Many thrive in wet conditions.

The bottom line is that floods kill grass. The longer it is covered in water, the worse it gets. So, timing is critical; the sooner it is cleaned up, the better.