All lawns and plants need direct sunlight for life. Sunlight is the solar power generator which drives the photosynthesis process in lawns and plants, which in turn provides food for lawn and plant growth. Sunlight is essential for our lawns to stay alive, to grow, and to stay healthy.
Different lawn types can tolerate and survive under varying levels of shade. Though no lawn variety can survive on 100% shade levels. Saint Augustine grass one of the most shade tolerant warm season lawn varieties there is, with up to 70% shade tolerance for the better varieties of Saint Augustine grass. Which in comparison to other grass types, is extremely good shade tolerance for any lawn. Zoysiagrass for example tolerates shade very well at about 40%, while a grass such as Bermudagrass cannot tolerate having much shade at all, with a preferred shade tolerance of about 10%.
All lawns, including Saint Augustine grass lawns, will naturally begin the thinning out of their thatch layer and leaf and sward density levels as shade levels on the lawn increase. The higher the shade levels, then so too is the greater the thinning out of the lawn, the lawn will also lose its dark green color and become more pale in appearance.
On heavier shaded areas we can often see that if that same thinned out lawn is used for any type of foot or other people traffic, then the lawn can very quickly disappear altogether, while under even the minimum of stress from wear or regular use.
Medium to heavy shaded lawn areas may just appear a little thinner than what may otherwise be considered normal for the lawn, as well as the lawn being a lighter and paler shade of green. Once again the wear and tear levels of this lawn will also be decreased.
As far as Saint Augustine lawns go in particular, they often actually seem to perform at their best and look their best whenever there is at least a little partial shade over them, rather than if the same lawn may be growing in full and direct sunlight throughout the day.
So with all these things in mind, if we have a shade problem on our lawns, which is affecting the lawn health, we need to choose a correct course of action to improve our lawns and yards under these conditions.
So let’s look at our options.
Remove Excess Shade For Improved Lawns
If we want to keep our lawns and want to improve their health and wear tolerance in shaded conditions, then our best option is to look at removing whatever may be causing the excess shade conditions over the affected lawn area.
Oftentimes this is from vegetation from overgrowing trees, bushes or shrubs.
A good heavy pruning can remove a lot of this shade for us, so this is our first port of call to begin increasing lawn health in shaded areas.
Fences or other yard structures may also be causing excess shade on other lawn areas. While we cannot move fences, we can look at whatever other structures may be in the yard and causing shade, and to consider removing or moving these structures to another yard location so as to increase sunlight to these lawn areas affected by too much shade.
No matter if our lawns are suffering the worst effects of excessive shade, or not, whenever we can increase direct sunlight to a lawn, and decrease shade, we are going to have better lawn health and better wear tolerance for that lawn, as well as better lawn color.
If We’re Unable To Remove Excess Shade Near Lawns
If the affected lawn area is being shaded by a house, or permanent fence, or permanent structure, and the lawn is struggling for health due to that shade, then there is nothing we can really do to improve this situation.
Our best option may be to remove the lawn in these areas altogether, and to instead plant a highly shade tolerant garden bed, or to put down some brick paving or other garden path in the area instead. Depending on the yard area, this may be a great place to put a garden shed instead of having lawn in that area. Whatever the case, the shaded lawn may have no other option than to be removed.
If we have a lawn type such as Zoysia or Bermuda growing in these areas, and the lawn is struggling, then it may be possible to plant a Saint Augustine lawn instead; to then have a lawn with a much greater shade tolerance. This option may be possible in some instances, but once again, the affected shaded lawn area will still need at least 30% or more direct sunlight each day at minimum, or otherwise a Saint Augustine lawn will also fail in these shaded areas.
The Number One Rule Of Lawns Growing In High Shade
Whatever our lawn condition is, and no matter the lawn type, if we are growing lawn in any type of heavier than average shade, there is one Golden Rule to always follow:
The more shade on a lawn, the longer we must keep the lawn leaf.
Remember, photosynthesis in lawns is solar powered by the sun.
And for that to work, it depends entirely on how much sunlight can get to the leaf area of the lawn grass.
So for a lawn growing in full sun, it only requires very little leaf area to power that photosynthesis. We can mow our lawns quite low when they are growing in full sun, and still have a very healthy lawn.
However, in shaded areas, we must do the opposite, and grow our lawns with a longer leaf in order for the lawn to capture more direct sunlight under these low light conditions. The longer the grass leaf, the more sunlight is captured, which powers more photosynthesis to the lawn, which finally provides enough food for the lawn to survive in lower light conditions.
Whenever shade levels increase on a lawn, so too should lawn mowing heights increase according to the amount of shade present.
Remember though, all lawns will still need some direct sunlight every day. There is no such thing as a no sunlight lawn. So whenever we can, we should remove excess shade, and / or increase lawn mowing heights, or finally, if these do not work in our situations, the lawn may need to be removed altogether and another use found for the affected area.