Is mulching leaves bad for grass seedlings? It depends on the maturity of your new fescue lawn and how long it has been since your fall seeding, but typically, this is not the ideal way to handle leaves on lawn over winter. When fall seeding overlaps with fall leaf season, there can be a difficult period in which gentle care of the lawn is still necessary, but too much leaf accumulation can be an equal threat to baby grass and even the lawn as a whole. As a result, the options come down to mulching the leaves as well as leaf blowing vs raking.
When considering the best plan for fall seeding a fescue lawn, it is important to identify the risk level your property has of significant fall leaf accumulation. There are three levels of fall leaf impact for a lawn:
High impact: These properties are usually in a wooded subdivision with heavily retained mature tree growth. High impact lawns have a heavy leaf removal requirement in the fall, but are also mostly or fully shaded, making the lawn less susceptible to complications from heat and drought during the summer. These lawns are best served by aerating and seeding in the first third of the fall seeding window when temperatures may still be on the high side, but there is the greatest amount of time available before leaves begin to fall.
Medium impact: These properties are usually in a select cut subdivision with occasional mature tree growth, typically limited to thin natural bands along property lines, most often in the backyard. Medium impact lawns have a “typical” leaf removal requirement in the fall, with the primary focus being on select parts of the yard. These lawns have a balance between heat complications and leaf complications, with neither being extreme. These lawns are best served by aerating and seeding in the middle third of the fall seeding window when air and soil temperatures are cooling, but leaves are only just beginning to fall.
Low impact: These properties are usually in a newer clear cut subdivision with no mature tree growth on the property or on surrounding properties. Low impact lawns have little to no leaf removal requirement in the fall, but also have little to no shade, making the lawn more susceptible to complications from heat and drought during the summer. These lawns are best served by aerating and seeding in the final third of the fall seeding window when air and soil temperatures are cooler.
So, is mulching leaves bad for grass seedlings? Any kind of action on your lawn is going to risk damage to your baby grass when it is still in a fragile stage of development. As would make sense, this “danger zone” for your baby grass is a longer window of time for increasingly aggressive actions. For example, mowing is generally not recommended for at least four weeks after seeding is performed. Mulching leaves, typically done by mowing over an area multiple times to finely chop up leaf debris, causes significantly more wear and tear on a lawn than standard mowing would.
This is where the debate between leaf blowing vs raking comes into play. We’ve answered the question “is mulching leaves bad for grass seedlings?” with a pretty solid yes, but let’s explore the alternatives. Both raking and leaf blowing don’t involve heavy machinery the way that mowing and mulching leaves do, so either is fine, right? Well, not necessarily. If you weigh leaf blowing vs raking, using a blower to clear leaves off of a fescue lawn wins every time, and we will explore that further in a future blog. Either way, you still have to consider how much wear and tear these methods will do to your baby grass.
Where raking is concerned, the process of raking is very damaging to adult turf, let alone seedlings. This is a lot of mechanical action going across the lawn repeatedly, doing both foliar damage as well is uprooting newly established growth. Blowing is by far a more gentle process and the best option, but does come with the risk of disturbing ungerminated or newly germinated seed if done with too much force.
At the end of the day, if the majority of what is visible across the surface of your lawn is fall leaves and not grass, then those leaves need to be removed. Leaf accumulation blocks air, water, and light from reaching the grass it is covering, which can smother and kill a fescue lawn before it even had a chance to turn into something beautiful. Where fall seeding and fall leaves are concerned, the best option is to know your yard’s level of leaf impact and then plan accordingly.