Leaf compost perfect for perennial, shrub beds
Q: The local municipality gives away free leaf mulch in the spring. I was wondering if I could use this to revitalize my lawn and use it top dress my planting beds. If I spread a thin layer over my lawn, can I then spread grass seed on top• Or should I use top soil instead?
A: The leaf compost (also called leaf mold) given away by many municipalities is a wonderful, free resource. I fill my car with buckets of the stuff every spring. Many municipalities around Western Pennsylvania collect leaves in the autumn from street sides and parks and then compost it in windrows somewhere nearby. Sometimes they may add wood chips or grass clippings as well, which usually isn't a problem -- but if you're concerned with what went into making the compost, call your municipality and ask. The temperature of such a large pile is sustained at a temperatures over 160 degrees F for a long period of time. These temperatures usually ensure the compost is fully "cooked" and free of pathogens and viable weed seeds. That being said, always wear gloves when working with any compost or manure products and wash well when you're done.
Finished leaf compost is perfect for perennial and shrub beds. I use 3 to 4 inches of it to mulch my perennial beds every spring. Be careful not to cover the plant crowns and don't put any where you expect self-sowing plants to grow. Keep all mulch 2 to 3 inches away from the base of perennials, shrubs and trees.
As for your lawn, if possible, screen the compost first through a sifting sieve made of hardware cloth to break up any large clumps. An alternative method is to use your gloved hands to break up any large clumps before flinging the compost over the lawn with a shovel or spading fork. I suggest spreading 1/4 to 1/2 inch on the lawn once or twice per year. You can do this either after or before seeding (I prefer after so it helps protect the seeds from marauding birds and holds it in place until germination). The compost feeds your lawn as well as all the beneficial soil organisms below it.
As for using it in the vegetable garden, it depends. If you can confirm that the only ingredient was leaves, I'd say it's more than safe to use there. But if large quantities of grass clippings were used in the compost's creation, you may want to skip it on the veggie patch just in case.