Lawn Still Yellow in May? 4 Common Causes and How to Quickly Fix It – For Lush, Green Grass in Summer
Now is the time to fix up your lawn before a scorching summer
After winter, it's not uncommon for our lawns to look a little tired and damaged from freeze-thaw cycles, improper drainage, and general damage from harsh conditions. But, if your lawn still looks yellow in May and hasn't quite recovered, it's a sign a big adjustment is needed.
Even if you have done everything on your spring lawn care checklist, it's likely your lawn will still looks yellow in late-May if there's a bigger health issue, such as a drainage problem or even a pest infestation. But don't fret, it is possible to recover your lawn before scorching summer temperatures arrive.
Lawn care experts say the best thing to do is diagnose the issue and act with care to nurture it back to life. Here, they talk through four possible causes and how to fix them.
1. Drought
One of the main causes of a yellow lawn in May is drought. With spring temperatures fluctuating and temperature spikes towards the end of the season, it can be tricky to properly manage watering your lawn.
'If your entire lawn (or most of it) is yellow or brown, you should suspect heat or drought. Both of these problems are actually the same – not enough water is getting to the roots of your grass,' says Chris Ramos, lawn care expert from Blain's Farm & Fleet.
'In very hot weather, the sun can evaporate most of the moisture from rain and light watering before it’s had enough time to soak into the soil around the roots of your grass,' he explains.
To check the moisture levels of your lawn's soil, use a soil moisture meter (like this from Amazon).
You should then think about how long to water your lawn and how to protect your lawn during a heatwave.
You should water early in the morning and late in the evening to hydrate your lawn, avoiding watering it in the middle of the day during hot spells as this can scorch it.
'For better long-term protection against heat and drought, use a fertilizer mix with high phosphorous and potassium levels (like this from Amazon)' Chris suggests.
'This will strengthen your lawn and help it grow deeper roots, which will allow it to resist lawn problems like drought and heat in the future,' he explains.
Chris is a lawn care expert at Blain's Farm & Fleet. He offers advice on a wide range of lawn issues.
2. Drainage
Drainage is another common cause behind yellow lawns, and with irregular and sometimes unpredictable rainfall patterns in spring, it may be that your lawn is struggling with excess water this season.
If your lawn is quite compacted from winter and you're yet to aerate your lawn, then there isn't much room for water to drain away. This results in grass roots becoming oversaturated and rotting, causing discoloration like yellowing.
This can be the cause behind brown patches on lawns, too, where specific areas have particularly bad drainage.
To fix this issue, use a lawn aerator tool (like this from Lowe's) to punch holes in the soil, creating air pockets for water to drain. You can also use methods to loosen compacted soil to improve the structure of your lawn's soil.
You may also need to dethatch your lawn if there's a lot of debris and moss on the surface, which you can do with this thatch rake from Amazon. This will provide more light and oxygen to the grass.
Adding organic compost can also help improve lawn soil health and structure.
You can then overseed your lawn to help it recover before summer settles in, or even use this Scotts patch magic lawn repair from Amazon for specific areas in the garden.
Going forward, water your lawn carefully as to not overwater it, paying attention to rainfall. You may even want to install a French drain to help reduce water surface run-off.
3. Pests
If drainage and watering aren't an issue and your lawn is yellow in May, Chris recommends taking a closer look at your grass.
'If you see any holes or brown, yellow, or orange spots on the blades of your grass, you may have an insect infestation,' Chris says.
'Also, check the dirt between your grass blades for small holes or insect eggs. Insects can damage your grass by chewing and eating the blades or roots,' he explains.
There are lots of spring garden pests to look out for when it comes to your lawn. Lawn grubs, leatherjackets, anthills, and sap-sucking grass insects can all weaken your lawn and leave it looking patchy and discolored.
Luckily, there are plenty of natural pest control methods you can use to resolve this issue.
One of the most reliable is turning to the help of beneficial nematodes – microscopic organisms that prey on a wide range of destructive pests, taking care of the issue for you.
You can purchase beneficial nematodes at Walmart.
4. Nutrient Deficiency
Another cause behind a yellow lawn in May is a nutrient deficiency. In particular, a lack of nitrogen (the essential plant nutrient responsible for green vegetative growth) can result in discoloration and a lack of new growth.
If you're yet to fertilize your lawn in spring, this is a likely cause.
'Lack of nitrogen fertilizer or a fertilizer application that runs out of steam won’t keep the lawn deep green,' explains Dr. Roger May from TruGreen.
'Likewise, when soil pH is too high (alkaline), essential nutrients like iron and manganese become harder for grass to absorb, resulting in yellow turf spots, stunted growth, and weak root systems,' he adds.
To be sure of what is happening in your lawn's soil, use a soil test kit (this one from Amazon is highly recommended).
You can then use things like turf boosting lawn fertilizer (like this from Lowe's) to encourage your lawn to become green and thick before summer.
Just watch out for lawn fertilizing mistakes, like applying fertilizer during a heatwave which may burn the roots and cause further damage.
Roger May, PhD, is the Director of Operations Support for TruGreen. He's a lawn care expert and offers advice on a wide range of lawn issues.
What to Shop
This lawn aerator has 12 spikes to effectively punch holes into lawn soil to improve drainage.
This thatch rake is designed to effectively remove moss and debris from lawns, improving light and oxygen for grass beneath.
This Scotts turf builder lawn fertilizer helps strengthen grass roots and enhances the lawn's ability to absorb water and nutrients.
As we move into June, don't forget to read up on summer lawn care. This includes watering deeply in the morning to keep your grass hydrated during hot spells.
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