Water damage is no joke. Help your lawn recover from flooding before the damage gets out of hand, costing you even more precious time and money.
You can do everything right for a healthy green lawn, just for a heavy rainstorm to wash away your hard work. Don’t let the elements get you down: Follow our tips to help your lawn recover quickly from a flood.
In this article:
What does flood damage look like?
Flooding will impact your property differently, depending on the power of the storm, your property’s slope, your landscape and hardscapes, and the grass type you have. Some flood-resistant grasses can survive several days or weeks of flooding, while others will suffer significant damage from lingering puddles.
- Primary flooding damage: caused by the depth and temperature of the floodwaters.
- Secondary flooding damage: caused by moss, disease, sediment buildup, and weed encroachment after the flood has passed.
Floodwaters also can kill grass by suffocating it; the lack of oxygen can harm your grass, depending on the length of the flood. Just a couple of days with your lawn submerged in floodwaters can be enough to kill it, especially if the water temperatures are high.
Lawns experiencing flood damage might have:
- Lingering puddles
- Patches of dead grass
- More weeds
- Brown or yellow grass blades
How to tell if your grass is dead:
After a flood, you might be left wondering if your grass survived the storm. You’ll need to be patient and wait several days to see if your lawn will recover. No new grass growth can be a sure sign your lawn has died.
You also can determine if the turfgrass has died by looking closely at individual grass blades. Healthy grass blades should have a white crown, which is the area where the turfgrass shoots and the roots meet. If the crown is brown, that grass is dead. If you see new, green shoots popping up from the ground, your grass is making a triumphant comeback.
Heavy rain can lead to lingering puddles and patches of disease-ridden or dead grass. But with proper lawn care, you can help heal your flooded lawn.
How to help your lawn recover from flooding
1. Pick up debris
Once the storm has passed, grab your gloves and rain boots, it’s time to risk getting a little muddy now for a healthy green lawn later.
Depending on the ferocity of the storm, you might be dealing with large debris. Grab what you can, being careful to spot small debris like nails, glass, metal, and other sharp objects.
These objects can damage and smother your lawn if left for too long. They are also hazardous to you, your pets, and your children, especially if you neglect to pick them up before your next mow.
2. Clean up silt deposits
After a flood, a layer of soil, sand, or silt can be left on top of your lawn. It might seem harmless because you think it will wash away after the next rainstorm. However, a layer of sediment left on your grass blades can be quite damaging.
If the layer of soil or silt is thick, it could cover, suffocate, and kill your grass.
How to remove sediment from grass:
- Step one: Wait a couple of days for the ground to dry slightly
- Step two: Grab a shovel and/or a powerful hose
- Step three: Use the shovel to scoop and scrape away excess soil, silt, sand, and muck
- Step four: Use a hose to rinse the remaining sediment from the turf
3. Soak up puddles
Get rid of standing water on your lawn before it has the chance to damage your lawn.
How to soak up puddles after a storm:
Sprinkle organic matter, like compost, on top of the puddles to soak up the water. Once each spot has dried, rake the compost into your lawn to make your lawn look nice and even while giving it a boost of nutrients.
In addition to compost, you also can use:
- Mulch
- Topsoil
- Animal manure
- Peat
4. Aerate your lawn
Flooding can lead to compacted soil, but that’s not the only reason you should aerate your lawn after a flood.
Lawn aeration helps oxygen and nutrients flow through the soil, and can help break up layers of soil deposits left from the flood. If you live in an area with high flood risk, aim to aerate and dethatch your lawn every year or so. Aerating ahead of the storm can help the water seep into the ground faster, preventing the damage that can be caused by standing water.
Core aeration is the best method for flood-prone lawns because larger plugs of soil are removed compared to spike aeration.
When to aerate your lawn:
Wait until your lawn is still moist, but not so wet that it will cause a mess. To tell if your soil is ready to be aerated, try the “squeeze test.”
Dig out a handful of soil and squeeze it. If it is dripping wet soil, it should be left to dry for a couple of days. If the soil is moist and crumbly, you can aerate your lawn.
How to aerate your lawn:
- Step one: Locate and mark utility lines or sprinkler heads that might get hit while aerating
- Step two: Use a manual core aerator to “mow” over your lawn twice, removing plugs of soil
- Step three: Rake soil plugs into your lawn or allow them to decompose
- Step four: Add soil amendments like compost and fertilizer
- Step five: Overseed up to a month after aerating for best results
5. Encourage grass growth
Overseed or reseed?
Wait a couple of weeks after aerating to see what shape your lawn is in. If there are bare patches, go ahead and overseed the thinning areas with grass seed.
If the damage is extensive, meaning less than 40% of your lawn recovers from the flood, consider starting over from scratch with a new lawn.
You can resod your lawn any time of year, but if you have cool-season grass, you’ll need to wait until mid to late August to reseed. Cool-season grasses don’t establish well in the heat of summer.
Water properly
Watering your lawn might seem simple enough, but improper technique can lead to a pest and disease-ridden yard.
- Water in the early morning hours between 4 a.m. and 10 a.m.
- Water when your grass is showing signs of stress (dull color, curling blades, slow recovery from foot traffic)
- Soak the soil 6 to 8 inches deep while watering to encourage deep root growth
Mow regularly
Make sure you wait until the ground is dry before mowing. Mowing on wet grass can lead to compacted soil and a muddy mess.
Mow regularly to stimulate grass growth, but let the grass grow long. Set your mower to the highest setting for a high cut to encourage your grass to grow strong, dense, and deep-rooted. Mow weekly or every other week, depending on your grass type and the time of year.
Be sure to avoid mowing more than one third of the grass blade when you mow, and check that your mower has sharp blades. Scalping or cutting with jagged blades can further weaken an already damaged lawn.
6. Fertilize
Floods can wash away nutrients, especially nitrogen, from the soil. Silt deposits and excessive moisture can encourage weed growth. After the storm has passed and new grass shoots have started popping through the ground, fertilize your lawn to give it a nutrient boost and keep pests, weeds, and disease at bay.
- Get a soil test after a storm to see how it affected your lawn’s nutrient levels and pH. You can conduct a DIY soil test at home, but the best option is to send a soil sample to your local Cooperative Extension Office. They can determine more precise information about your soil’s health.
- Apply nitrogen-based fertilizer to your yard. Slow-release granular fertilizer is the ideal choice for your lawn’s long-term health, but liquid fertilizer can work for an immediate boost of nutrients.
- You also can use homemade fertilizers and organic fertilizers like compost, blood meal, and corn gluten meal.
7. Look out for weeds
Some lawn weeds might still pop through even after you nurse your lawn back to health. Weeds thrive in wet, compact soil, which is why your lawn is so susceptible to them after a storm.
How you control weeds depends on the time of year and the type of weeds you’re dealing with.
- Apply a pre-emergent herbicide in mid-March to get ahead of weeds that pop up in the spring and summer, or apply pre-emergent in early- to mid-fall to prevent fall and winter weeds. Pre-emergent herbicide targets crabgrass, clover, dandelions, ragweed, bluegrass, prickly lettuce, foxtail, and chickweed.
- Post-emergent herbicides are best applied between early spring and late summer but work most effectively when air temperatures are below 85 degrees. Post-emergent herbicide works on weeds such as clover, crabgrass, bramble, thistle, nutsedge, dandelion, and chickweed.
Don’t apply herbicides if there’s another storm on the horizon or your efforts will be washed away.
Here are some other ways to prevent and eliminate common weeds:
- Apply broadleaf weed herbicides
- Weed by hand
- Apply organic herbicides
- Pour boiling water over the weeds
- Spray weeds with a mixture combining cheap vodka and dish soap
FAQ about helping your lawn recover from flooding
Extended periods of flooding can be expensive and exhausting to deal with. Get ahead of flooding by adjusting your lawn and landscape.
• Reduce shade
• Add more vegetation
• Design a rain garden
• Improve drainage by installing french drains, dry wells, and channel drains
• Build a dry creek bed
• Add a swale
• Use a rain barrel to collect stormwater
• Add mulch around your landscape
• Place sandbags around your landscape ahead of a storm
Grass types that can stand up to rainstorms and floods should have deep root systems and be hardy against excessive moisture. Flooded lawns are also prone to secondary damage, like fungal diseases and pest infestation, so the ideal grass should be durable against those, too.
For these reasons, two of the best choices for homeowners who deal with flooding regularly are:
• Tall fescue
• Bahiagrass
Avoid perennial ryegrass if your yard is prone to flooding. It is very susceptible to weather-related damage and fungal diseases.
Lawn flooding is more common than you’d think because it’s not just caused by extreme weather events like hurricanes or tropical storms.
But where is the excess water coming from?
Are puddles appearing on your lawn despite a lack of rainfall? Check your lawn irrigation system settings to make sure you’re watering at the right time of day and not overwatering your lawn.
Here are some other common reasons why your yard is flooding:
• Poor soil drainage
• Uneven or poorly graded lawn
• Low elevation
• Clogged gutters
• Compacted soil
Prepare ahead of the flood
Thanks to climate change, we are dealing with more frequent flooding in the United States. Flooding has cost the nation more than 75 billion dollars in damages over the past three decades, and scientists are predicting that this is just the beginning.
There’s not much you can do in the wake of a natural disaster other than staying prepared. Be aware of your own risk: Check if you live in a flood zone, and stay tuned to your local weather channel to stay informed ahead of major weather events.
In addition to staying informed, keep your lawn in tip-top shape and:
- Level your lawn to prevent ponding
- Install drainage systems
- Fill in bare areas with new turfgrass or deep-rooted plants
- Strengthen new sod or new growth by practicing proper lawn care
Avoid extensive flooding damage by having a healthy lawn in the first place. Reach out to a local Lawn Love pro to help with all your lawn care and landscaping needs ahead of the storm.
Main photo credit: George Roger Gilbert | Flicker | CC BY-SA 2.0
