Overseeding Bermuda with Zoysia is tricky to carry out on the lawn. Both are fast-growing and invasive warm-season grasses that are easy to take care of.
However, there are a lot of things to be considered when it comes to Zoysia vs bermuda and growing both these grasses together.
In this article, we will answer all your important queries regarding this grass combination.
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- Is Overseeding Bermuda With Zoysia A Good Idea?
- Why Shouldn’t You Overseeding Bermuda With Zoysia?
- Overseeding Steps
Is Overseeding Bermuda With Zoysia A Good Idea?
Why Shouldn’t You Overseeding Bermuda With Zoysia?
The reason why you shouldn’t overseed Bermuda with Zoysia is that the latter will invade over the former, due to its aggressive growth. Also, both types have different watering needs, and different mowing periods. Lastly, growing together you will see zoysia causes thatch build up.
– Zoysia Will Invade Over Bermuda
Zoysia grass is considered an invasive species in the US, and overseeding any other grass with it is always a risk. The only thing that hampers the growth of this grass is cold temperatures, especially from late fall till late winter. So if you live in a warm region where the summers are hot and the winters mild, Zoysia will grow rampantly and might even take over the entire lawn as the dominant grass.
You might be thinking that Bermuda is also an invasive grass species. However, when the growth potential of Bermuda and Zoysia are compared, Zoysia will overtake Bermuda under the right conditions. Even in regions with cold winters, Zoysia will gradually take over Bermuda little by little each spring and fall.
After a few seasons, the entire lawn might become Zoysia predominantly. This is an imperative factor to keep in mind while overseeing Zoysia. In the case of Bermuda, it might take several years because Bermuda itself is invasive and gives Zoysia tough competition.
– Both Types of Grass Have Different Water Needs
Zoysia and bermuda grass are warm-season grasses but have slightly different care requirements. This is particularly important regarding the light and the water requirement of both types of grass.
Bermuda is a drought-tolerant grass variety that needs only half an inch of water every week to keep it green. This grass can withstand dry conditions of drought for over five weeks during the peak of summer. The same, however, cannot be expected from Zoysia.
It thrives well with one inch of water per week but could do better under drought conditions. So if your neighborhood experiences drought for more than two to three weeks, the Zoysia might not survive as well as Bermuda does.
– Different Mowing Periods
Once you have overseeded a bermuda lawn with Zoysia, you must not mow it for the next four to six weeks. This is the approximate time that needs to be given to the new grass blades before they can survive being cut.
The first cut after overseeding is also slightly different from your usual mowing. Keeping the height of the cutting blade as high as possible, first mow only one-third of the grass. If it still needs further mowing, then do so after a period of three to five days.
– Zoysia Causes Thatch Build Up
This is another incompatibility between these two grass types. Bermuda is a low-spreading grass that grows through horizontal stolons and produces very little thatch throughout the year. Ideally, it needs to be dethatched about once a year, but you can also go without detaching it for two years.
On the other hand, Zoysia has an upright growth habit and needs to be mowed more often. This grass produces a lot of thatch and needs dethatching at least twice yearly. When bermuda is overseeded with Zoysia, this excessive thatch seriously affects the growth of Bermuda.
Being a low-growing grass, it needs help gaining access to light and air. You must pay attention to regular thatch removal as part of lawn care if you want to see your Bermuda thriving in this particular case.
– Incompatible Shade Tolerance
Bermuda needs unrestricted access to direct sunlight all day to grow at its best pace. At the very least, it needs about seven to eight hours of direct sunlight in order not to die.
This is not grass you can plant on a shady lawn but another shade-intolerant variety like Zoysia. After overseeding such a lawn with Zoysia, the grass seeds will not germinate, nor will the grass spread. On the contrary, it will become dormant, and this would be a challenging task.
Many of us have certain sections of the lawn that are shady or not as brightly lit as the rest. That is why you need to go for a grass mix that combines Bermuda with a shade-tolerant variety.
The steps to overseed Bermuda with Zoysia are to choose the right time, spray herbicides on the lawn and clean it, mow two inches at first, and make sure you would properly irrigate it. Then you should start sowing Zoysia, and place some peat moss.
Now, as mentioned, this is a very challenging task, but the choice is up to you, because it is possible, although it is quite a journey. If you have decided to overseed your bermuda lawn with zoysia grass, then the rest of the procedure is pretty simple.
– Choose the Right Time
The best time to overseed bermudagrass with Zoysia is mid to late spring season. As both are warm-season grasses, this is a period of peak growth for both. The seeds will grow at their maximum rates during this time. Stay calm if you have missed this period because both these grasses will also germinate reasonably well through summer.
Only bother with overseeding once temperatures start dropping at the end of summer. This is when very few if any, warm-season grasses will germinate and grow till the next spring.
– Spray Herbicides
If you must carry out any chemical weed eradication on the lawn, then do so at least three months before overseeding.
Take a non-selective, pre-emergent herbicide, spray it all over the lawn, and wait until it kills the weeds. After the weeds have been killed, you can manually take them out of the ground.
– Mow Two Inches
Mowing Bermuda grass already growing in the lawn to a height of one and a half to two inches. This would make it easier for the Zoysia seeds to reach the ground and get nutrients from it.
This task will boost the growth, and remember that you are taking your time in growing the Bermuda first and aiming to take control over the other variety well.
– Clean the Lawn
The next step is cleaning the lawn of any potential debris like stones, rocks, etc. It is also prudent to carry out dethatching of the entire lawn to better aerate the soil.
All these steps will increase the chances of successful seed germination for Zoysia.
– Properly Irrigate
Technically, it would be best to start watering the soil every day for a week before seeding. On the other hand, you can only water an already-established bermuda grass lawn so much by overwatering it.
What you can do is just water the lawn a moderate amount a day before overseeding to a depth of four to six inches.
– Star Sowing Zoysia
Measure the exact dimensions of the lawn and obtain the appropriate quantity of premium-quality Zoysia seeds for it. Use a seed spreader to sow seeds instead of randomly spreading them using your hands.
Now, you should try to divide the lawn into rows and columns visually and walk along them, pushing the seed spreader forward. To make things much easier for you, you can always use a rake to mix the zenith Zoysia grass seeds with the soil gently.
– Place Peat Moss
This next step is optional but helps with rapid germination, simply, you can place a thin layer of peat moss over the sowed seed less than half an inch thick if the layer is thicker than that.
This would secure the humidity level and the process to boost up well, as it might impede germination. Keep constantly watering the next whole week and then gently taper off until the seeds germinate at the end of four weeks.
So far, we have discussed how to overseed a bermuda lawn with Zoysia in great detail.
Here’s what we covered about this grass mix:
- We recommend that you overseed bermuda with cool-season grass such as perennial ryegrass.
- Zoysia is less drought tolerant than bermuda and will die unless watered for three to four weeks.
- Spring is the best time to carry out this overseeding with Zoysia.
We hope you will take help from the points given in this well-researched guide the next time you try overseeding a bermuda lawn with Zoysia.