Sod Overheat: The Ultimate Guide to Prevention!
So, you’ve got EVERYTHING figured out… You’ve prepared your land, your sprinkler is ready and waiting, and the sod is being delivered so you can put the finishing touches on your yard! Unfortunately, it’s sweltering hot out and once the sod arrives, you notice it feels quite warm… Did your sod overheat?!
“What happened to my sod?! Did it overheat?!”
Once you start to lay the sod, you notice that the sod is getting hotter and it’s even starting to turn brown! What is going on here?! You’ve spent money, time, and energy to get to this point and now there’s something wrong with the sod?!
This can be incredibly frustrating, especially if you don’t understand what went wrong. Let’s break down exactly what is happening when a skid (or pallet) of sod overheats. It’s all about airflow, pressure, and of course heat!
Why Sod Overheats
During harvest, sod is rolled and stacked on a skid in a cube shape. This is an incredibly convenient way to move a large amount sod, but it does have its downsides when the weather is hot. We always have to remember that sod is alive, and it is a perishable product. We don’t naturally think of airflow as an essential factor in sod establishment, but your grass (like most other plants) needs air to survive. Stacking the sod restricts airflow to the middle of the skid which can choke out some of the middle rolls.
Another factor effecting the condition of sod rolls on a skid is pressure. Sod can be incredibly heavy. When the rolls are stacked, there’s a lot of weight pressing down on the middle rolls. This downward pressure acting on the skid has a negative compressing effect, similar to when you walk on freshly laid sod. Compressing the sod rolls can be detrimental to the overall health of your turf.
The third and final factor contributing to sod overheat is rather obvious: heat. Think back to elementary school science class for this one… There are three different methods of heat transfer: conduction, convection, and radiation. Conduction is the transfer of heat through solids, convection is the transfer of heat through liquids or gases, and radiation is the transfer of heat that does not depend on contact between the two objects. All three methods of heat transfer are acting on a skid of sod during a hot day.
Where Does All this Heat Come From?
First of all, the sun radiates heat onto the outer sod rolls. Luckily, these outer rolls get plenty of airflow which pulls some heat away through convection. The inner rolls aren’t quite so lucky… The rest of the heat from the outer rolls is transferred by conduction towards the middle of the skid. When all 5 sides of the skid are heated by the sun, it creates an “oven-like” effect. The image below is a visualization of the “heat zone” that can develop if the skid is left out for too long.
Timing is Key to Prevent Overheating
As you can see, timing is key when it comes to sod installation. The shorter the time between harvest and install, the better. On a very hot day, a skid of sod can overheat in as little as 8 hours. For comparison, in cooler spring conditions, sod can survive on a skid for up to 56 hours! Take this into consideration when you’re planning a sod project. Spring and fall typically have more favourable sod-laying conditions than the middle of the hot summer.
This is a rough guideline. Sod can overheat faster/slower depending on field and weather conditions.
Some other factors that affect the time it takes for sod to overheat are: humidity, soil conditions, the seed-head production cycle, and overall nutrition levels. These factors don’t contribute quite as much to sod overheating as airflow, pressure, and heat, but they can still play a role. Ask your local farm if any of these additional factors will affect your project.
Precautions to Take To Prevent Sod Overheating
If you can’t avoid installing sod on a hot day, there are a couple of ways you can try to keep it cool. First off, placing the skid of sod in a shaded area will help prevent the sun from heating things up. If the sod is going to be waiting on the skid before you can install it, pull the individual rolls apart and place them side by side with enough room for air to circulate. By breaking down the skid, you are allowing air to cool each roll, and you are also preventing that “oven-effect” from happening.
Be sure to closely monitor your sod and follow the best practices we laid out here. Break down the skid, and remember to NOT water or cover it. Ideal sod laying conditions are usually in the spring and fall. If you can’t avoid a mid-summer install, do your best to prevent overheating.