Last Updated on October 28, 2021 by Mark Brian
One of the most widely planted grasses is the St. Augustine grass. Hence it is a star grass in the southern states, commonly falling in USDA zone 8 to 10. However, given certain situations, St. Augustine grass can wilt fast. So how to get St. Augustine grass to grow back?
Yet there is one condition, that is the grass should not be already dead. So you can have some hopes for it to rise from the ashes like a green phoenix.
Some reasons for St. Augustine grass to wither away can be fertilizer burn, brown patch fungus, drought stress, frost burn, dormancy, grub infestation, or poor soil conditions. All of these lead to the yellowing of St. Augustine grass, and eventually its death.
How to check if St. Augustine grass is Dead or Alive?
A crucial question arises before you try and be a hero for your lawn. How to check if saving the lawn is worth a shot or is it too late? A simple way to check that is the pulling method. It is as simple as it sounds.
First, spot a yellowing or a brown area where you suspect the turf is dying. Then, grab a handful of grass, leaves and gently pull them out. If the grass shows no signs of resistance and comes right into your hand, it is most likely dead. Therefore, you should replace it with new turf.
On the other hand, if you feel some resistance and the grassroots stay put in the soil then it is probably alive. Even though at the moment it may seem dead. St. Augustine grass that has been dormant or yellowing for 3 to 5 weeks can be revived. However, grass past 6 weeks in such a state is usually dead.
Why is My St. Augustine Grass Turning Yellow?
Often known as buffalo grass, St. Augustine grass has high shade tolerance and moderate drought tolerance. This makes it a competitive grass when it comes to bermuda grass vs buffalo grass.
Some lawn keepers are interested in mixing bermuda grass with St. Augustine grass, which makes the situation tricky. In contrast, it could be only St. Augustine grass on the whole lawn. In either situation, the grass can turn yellow. Some possible reasons for this could be:
Although St. Augustine grass is drought tolerant, it can also only tolerate a certain amount of water. Excessive watering or heavy rains without any drainage can lead to stunted grass growth causing yellowing. Undrained water for longer periods is a hub for harmful bacteria and fungi to grow as well.
As St. Augustine grass types are native to the tropical and Mediterranean climates, so it can get very hot. Thus, high temperatures can trigger chlorosis because the grass is stressed and unable to take up nutrients. This occurs if the grass is mowed too low around 1 to 1.5 inches in summer, causing it to yellow.
Japanese beetles commonly called grubs or white beetles are the nemesis of St. Augustine grass. They feed on the roots of the grass, cutting off the grass’ connection with the soil. Hence all the nutrients and water lay useless when the roots are gone, and the grass dies.
A brown peppered or yellowing grass is a major giveaway for grubs. A small tug test can clear your doubts. Just pull the grass with a little tug. If it comes out like a carpet, without any significant force, then it’s grubs eating your lawn away.
Climate change is enormous around the globe, and it has produced some major climatic shifts. Likewise, winters appear harsher, and it can be taxing for St. Augustine grass. Just like many other types of grass, it goes into dormancy and if not revived within a few weeks, it can have frost burn.
Frost burn happens when grass freezes over and becomes rigid. Consequently, mowing or walking over it can harm it irreversibly. Owing to this fact, any break in the grass can be fatal and it may remain yellow when the spring arrives.
St. Augustine grass is almost an evergreen grass, but it can go into dormancy because of the climate. Also, it remains in its tan dormant form until the temperature is 55 ℉. Due to low temperature, drought stress, and desiccation through winters, St. Augustine grass appears brown. However, constant watering can solve this problem for you.
You can use the best lawn mowers for St. Augustine grass and still come across chinch bugs. This is because they exist on the curbs of the lawn, making colonies. So, how exactly can you spot a chinch bug infestation?
A common giveaway is a circular brown patch amidst the green grass. It lacks all the moisture and nutrients from it, so much that it is practically hay. Additionally, you’ll notice a pink or brown hue to the grass, running on the edges or through the midsection. Effective pest control and replacing the sod remain only options if St Augustine grass gets infested with chinch bugs.
Usually, St. Augustine grass faces drought conditions in summers when water availability is low. This can desiccate grass leaves, turning them yellow. Proper and regular watering can safeguard the lawn against it.
Take All Fungus
Just like bugs, fungi are a culprit for yellowing and killing St. Augustine grass. It is a root rot disease and occurs due to fungi residing in the soil. Additionally, it occurs as irregular or circular patches of yellowing St. Augustine grass. If untreated, the grass turns brown and dies.
Brown Patch Fungus
A specific species of fungus, Rhizoctonia, is responsible for big brown patches of bare lawn. This type of fungi thrives in a humid climate with a temperature over 80 ℉. The Yellowing and thinning of St. Augustine grass start in mid summer when the weather is humid.
Excess of everything is bad, and so it does for fertilizer as well. Meanwhile, nitrogen is essential for grass growth; overfertilizing can cause fertilizer burn. In other words, putting more than 1 lb per 1000 sq. ft. in the grass will burn it.
Excessive nitrogen salts can wilt the grass, especially when applied on wet grass. Such damage cannot be reversed, even with the best lawn mower for wet grass.
Poor Soil Quality
One of the often overlooked causes for yellowing St. Augustine grass is poor topsoil. Any topsoil having silt, sand, and lacking the essential nutrients is considered poor. When the grass is unable to draw its required water and nutrients, it starts yellowing.
How to Get St. Augustine Grass to Grow Back?
If St. Augustine grass shows yellowing or brown tan then check any of the above reasons. Now, how to get St. Augustine grass to grow back after tough winters or some pest infestation?
If it’s been only 3 to 5 weeks, then your lawn can be salvaged. You can do it yourself in the 5 easy steps given below:
When it comes to dry or winter torn grass, regular watering up to 1 inch can grow St. Augustine grass back. However, if the grass turned brown due to hot summers, watering it up to 6 inches is suitable.
Once the grass is hydrated, it can grow new roots giving way to a green sod. Regular watering 2 to 3 times every week produces great results.
Lawn mowing is a science of adjusting lawn and climate conditions in a harmony. If St. Augustine grass is brown then give it some days to green up through watering. Otherwise, you will be risking raking the lawn from its roots.
Once the St. Augustine grass is somewhat green, mow it at the highest setting of 3 to 4 inches of your lawnmower. So the new shoots can grow from it.
Although St. Augustine grass has low foot traffic tolerance, it can become compact. Furthermore, soil compaction can reduce air pockets in the soil and hinder grass growth and building up thatch. In such a case, dethatching is a viable option.
Fungicide and Pesticide
As we discussed earlier, bugs and fungi wreak havoc if they are left unchecked on the lawn. So, to get rid of grass destroying bugs and fungi, it is important to have a spray of fungicide and pesticide. Also, avoiding wet and humid grass will increase grass growth.
Many of us are familiar with safety cushions. Well, overseeding in fall is exactly a safety cushion for St. Augustine grass. As the grass proceeds into winters, some seeds remain healthy and dormant. So when spring arrives, these new seeds flourish. This helps St.Augustine grass to grow back early.
Planting New Sod
If all else fails, and the grass is beyond saving then you can plant new sod in its place. St. Augustine grass beyond 6 weeks of tan brown is dead with no symptoms of recovery.
It can be expensive if the entire lawn is dead. However, in most cases, it is certain patches of lawn. So, replacing them with new sod can return the lawn to its green beauty.
Frequently Asked Questions (FAQs)
Will St. Augustine grass reseed itself?
Unlike Bermuda or Zoysia grass, St Augustine grass does not have rhizomes and does not produce viable seeds. Replanting St. Augustine grass can be done either through sods or plugs.
Can I lay St Augustine sod over existing grass?
Yes, laying St Augustine sod over the existing grass will not only enrich the soil but also be good for the new sod. As the old dried grass will be a source of nitrogen and potassium.
What is the best time to lay sod St Augustine?
Spring or early summer is the best time to plant sods for St Augustine grass. Since it grows rapidly during the warm and humid season.
What month should I fertilize St Augustine grass?
You should fertilize St. Augustine grass in spring, only when it turns green. Applying fertilizer to brown grass can potentially burn it.
In a nutshell, St. Augustine grass can be resilient in face of drought, and winter stress. However, no lawn care can lead to adverse effects. The good news is you can grow back St. Augustine grass with 5 easy steps that work like magic.