Still More Leaves

I've finished the lawn--with 2,000 pounds of leaves in 97 bags, or a cube 8 feet on a side (and a bit).

Any remaining stock will go to increasing the leaf mulch on the drier southern face, plus repairing the soil in the areas the Township damaged and still hasn't fixed (on day 12 and still going!)

However, any remaining stock is going to be limited. Last weekend's storm took down most of the remaining leaves, and I expect about 20 more bags before the end of leaf season.

More Leaves

I've applied around 1,750 pounds of leaves to the lawn and I'm close to 80% complete at this point. The first areas of application are already invisible even applying at nearly 300 pounds per thousand. After a short period, the leaf litter breaks down into black organic matter that's invisible on the soil.

My current estimate is around 2,000 pounds of leaves (a full ton!) to complete the property. That should raise organic matter about half a percent in the soil.

Mulching Leaves on Your Lawn

In the past few weeks I've tapped two other properties of leaves to add to my own--with permission, of course. Both are kind enough to bag the leaves for me so I don't have to do it, and I'd like to extend my thanks (you know who you are).

So far, I've finished around 60% of the lawn and applied approximately 1,200 pounds of leaves (with some cut grass in the bags as well). I'll require a total of 1 ton of leaves, which works out to 285 pounds per thousand square feet.

So what do leaves do? They raise the organic matter percentage in the soil, provide fall food for your worms and micro-arthropods living in your soil, encourage bacterial and fungal activity in the soil, and mulch the soil for winter. Lawns that have been leaf mulched will retain their green color further into winter, green up faster in spring, and generally show greater health than lawns that receive no mulching.

How much should you use? Close to 300 pounds per thousand square feet disappears into the grass in a few days if well-chopped, but applications certainly do not have to be made at that rate. This study shows the results of mulching 150 to 450 pounds of leaves into the soil, and effects are generally excellent.

But isn't leaf litter ugly? Well, yes. The above study states that leaf litter at the highest application resulted in leaves still left on the lawn in spring. However, if you have a rotary mower it becomes easy to render the leaves invisible. With the very large amount I'm using, I mow slowly four times over the area to reduce the leaves to bits smaller than the nail on my pinky (and I have small hands!) By the time I complete the task, almost no visible litter remains--99% has fallen into the grass and becomes invisible. The remaining 1% disappears with the next rainfall.

What's the NPK ratio of leaves? Don't worry about it. Trees extract almost all the chlorophyll and nitrogen and place it in root storage for the winter. There is a small amount of phosphorus in the leaves, so mulching them is better than allowing rainwater to percolate through them while they sit on the street (my other post from today mentions eutrophication; leaves are one source of phosphorus that enters our waterways). Potassium levels are fairly low. The reason leaves are mulched isn't to feed the lawn but instead to provide additional organic material for the soil.