Tattered and torn, the last few leaves of this maple will soon fall. Leaves from healthy trees can be combined with fertilizer and grass clippings to make rich compost.
Carla Allen photo
Leaf it be
At the Memorial University of Newfoundland Gardens, plants are thriving in soil enriched by 20 years of leaf mold mulch. Tons of beech and maple leaves are gathered from the Government House in St. John’s each fall to be composted for three years then shredded and spread over the soil.
Now’s the time to rake up your leaves for processing into one of the best soil amendments there is. However there is a cautionary note for some property owners.
Earlier this fall, a reader contacted me to ask if I knew why many of the chestnuts and maples in the Valley were dropping their leaves early. I contacted several horticulturists I know and they offered their opinions.
Bill Craig, a horticulturist with Agri-Point in Kentville, says some maples suffered from ink spot (or black or tar spot) this year.
“Depending on the severity it can cause earlier leaf drop,” he said. “But the trees come back. It's not going to kill your trees, they will leaf out again.”
Craig suggests raking the leaves and disposing of them because the fungus will overwinter in them.
If your compost heap doesn’t reach a high enough temperature, you’ll only be spreading a well-aged fungus next spring. It might be better to ship diseased leaves off to the municipal composting facility where high temperatures during the composting process are pretty well guaranteed.
To compost leaves from healthy trees, it will speed things along if you shred them first. Rake leaves into a shallow windrow about 10 feet from a wall or fence and mow over them with the discharge aiming towards the barrier.
To compost effectively, layer with manure, grass clippings, or handfuls of fertilizer. One of the more novel compost accelerators I’ve read about is human urine... though you might want to add this after dark if providing it fresh.
A simpler way of turning leaves into a valuable soil additive is to spread a two to four inch layer over the garden and till or fork it beneath the surface. If you do this every year it’s possible to turn even heavy, clay-textured soils into a rich, root-friendly environment.
An interesting footnote for the phenomena that causes trees to drop their leaves; two of the triggers for this happening is the increasing length of darkness and cooler temperatures. When air is cold, it doesn’t carry as many water molecules per cubic meter as warm air. Deciduous trees drop their leaves as a means to keep moisture inside the vital tissue in trunks and branches.
