Make Room to Use Your Leaves

      This yard was fine bark mulched; it is now covered with blue star creeper, white thyme; and sweet woodruff; the brown is fresh locust leaves from the tree above.  They cover it through the winter. 

        Properties from tiny yards to large parks have trees for shade and beauty.  They produce leaves that mostly drop in the fall, and flowers, fruit and seeds that drop any time of year, depending on the plant.  These properties also may have lawns, shrub borders, paths, pavements, or even unplanted waste areas.

          Leaves and other tree debris must be removed from lawns, lest they kill the grass, though some can be mulched into the lawn without harming it, with the grass clippings.  They have to be removed from buildings, lest they rot roofs and clog gutters.  They have to be removed from pavements, lest they be a slipping danger, and as a matter of order and cleanliness.  They should be removed from paths, so they don’t rot the mulch, fill the gravel, or get tracked indoors.

          That leaves must be removed from some places does not make them trash.  They are not waste unless they are wasted by being hauled to the composter, because one is wasting their unique ability to stop weeds and feed soil naturally.  Burning them further wastes their potential use as compost mulch that can be used to stop weeds and feed soil, while polluting the air with the acrid scent of burning mulch.  But even hauling them to the composter costs money.

 Even a thin accidental mulch of soft maple leaves stopped a lot of groundsel from sprouting on the edge of this weedy field.

          Leaves have a truly unique ability to stop weeds because the top few layers dry quickly, making a poor place for seeds to germinate.  All other mulches are seed beds by comparison, not drying as fast on top and providing holes and cracks that seeds can settle into and sprout.  

 Fresh wood chips at Dimmick; the county started using them in 2012 on many parking lots.

The second best weed-stopping mulch is wood chips, which also layer and dry out on the surface, though not as quickly.  They are good mulch for paths; they even clean your shoes, and look nice and bright, freshly spread in mid-winter.  They also stay in place better than leaves, and can be used on steep, narrow parking lot dividers and berms.

Leaves should, therefore, be used on beds, shrub borders and unplanted areas to control weeds, which saves the work of laboriously raking and picking leaves out of the shrubbery.  They can be spread anywhere from 2 to 6 inches thick to control weeds and feed the soil, softening it for easy weeding of whatever manages to come up through the leaves.  A foot of leaves will grow huge vegetables while they decompose.

Fine bark, less than a year old, with the leaves "cleaned" out of it.  Note the black bark and soil.

 Many people like the “clean” look of finely ground or shredded bark, but it cannot stay clean for long, with leaves, flowers, fruit, and twigs constantly falling from trees and shrubs.  Few workers have the patience to clean them all out anyways.  In either case, scattered bits of organic debris do not look clean or pretty.  

 Plum leaves blend right into 3/4" nugget bark.

The more coarse the mulch, the more it hides the stuff that falls into it.  Nugget bark and walk-on fir work for this.  Leaves are not only the most coarse mulch, hiding all but the largest debris, but they do a much better job as mulch than anything else at mulch’s three jobs:  stopping weeds; holding water; and feeding soil.

Fine bark mulch has to be renewed regularly as it decomposes, turns black, and evaporates, which takes money to buy bark and labor to spread it.  Leaves renew themselves every fall and during the year as trees add stuff to the mulch, nearly all of which is welcome.  They just need to be moved from places that they don’t belong to the soil where they do, which is a lot less work and expense than cleaning them up and replacing them with bark.
 Lawns are good places for people and dogs to play and to have smooth, green open space to look upon.  They are high maintenance, but their care seems relatively uncomplicated compared to beds full of shrubs and flowers, since most of it can be done with machines, like mowers and blowers, which reduce stoop work.  They also need to be weeded, but using a mulching mower can prevent small-seeded weeds, like crabgrass, dandelion, and annual rye, from sprouting.

Still, if you have a lot of lawn, but not enough places to put your leaves, you have too much lawn and are doing too much work.  When beds and borders are maintained with leaf mulch, they are less work to maintain than lawn by a long shot: no mowing, and little weeding.  If they are generously large enough for the normal growth of the shrubs therein, little pruning is needed. 

Shrub borders are often built way too small.  Two to three feet wide around a building is common, requiring tight hedging, which is high maintenance and not as beautiful as the natural shape of the plant.  If it is, one might reconsider one’s choice of shrub for that spot.  

Hedges have their place for providing privacy and wind shelter in tight spaces.  Sometimes, they provide it to the wrong people; they are security problem.  But many shrubs are hedged simply because they outgrew their space.  Limb them up or cut them to the ground and either let them re-grow naturally or replace them with something that will fit the space better as it grows, and you will save a lot of work and have beautiful shrubs, instead of ugly hedges.  Limbing up is preferable for trees.

 A line-of-motion path, with nugget bark and japanese maple leaf mulch, and a Hinoki cypress starting to get in the way.

Same path the next summer, with the cypress limbed up and the path improved with 4 x 8 sand.

The natural line of motion for people and dogs to go around a building is a smooth curve.  The edge of the bed should come out to that natural walking line, if space allows.  Any lawn occupying that natural bed space can be mulched heavily with leaves and the grass weeded out as it comes through.  A border of good-size rocks can contain the leaves and provide a solid edge for a look of permanence.

Lawn with a curved border, and line of motion bed, partially mulched with leaves. 

Lawns can be shrunk to places most easily mowed.  Steeper slopes and sharp angles can be mulched with 6 inches of leaves and planted to ground covers, shrubs, and perennials. 

Make room for your leaves in your landscape by shrinking lawns and expanding borders, and you will do less mowing, need less weeding and pruning, and not be wasting work, taking leaves out of where they do the most good and are hardest to remove.  You don’t need to get rid of leaves, just rearrange them to where they will do their natural job of stopping weeds and feeding soil.

Rycke Brown, Natural Gardener        541-955-9040      rycke@gardener.com

Gardening is easy, if you do it naturally.

Using Leaves Efficiently For Mulch

Leaves are the cheapest and most effective mulch for weed control, when enough of them are used.  This natural gardener has been using them professionally on clients’ yards for 13 years.  All other mulches are seed beds by comparison.  Leaves feed the soil and thus the plants; soften it for easy weeding; and can stop sprouting of most small seeds, just by keeping the sun off them.  As long as leaves stick around, they stop germination of seeds that land on top of them, because the top few layers dry out quickly and don’t allow seeds on top to sprout.

One can smother nearly any annual weed, and many small perennials, with enough leaves.  But to be efficient with a client’s money, a professional gardener must figure out the least that it takes to do the job effectively when one has to bring them in from other places.

There is no need to shred leaves to use them for mulch in most situations.  Whole leaves are better for blocking weeds, but leaves can be mowed into a lawn, and shredded leaves will stay in place better where the wind would otherwise blow them around.

Only very large trees drop enough leaves beneath them to stop larger annual grass seeds like cheat and foxtails, but taking them from pavements, roofs, lawns, paths, and neighbors with too many and spreading them more thickly in beds and borders can smother grass seeds and young weeds while encouraging larger established perennials.

There are three basic classes of leaves as mulch: soft leaves; tough broad leaves; and tough conifers.  Black walnut is a soft leaf in a class of its own, containing a pre-emergent herbicide, juglone, that stops smaller seeds all summer, though their leaves are eaten before winter is over. 

Red maple leaves, blown onto a weed field from fine bark.  Not thick, but still smothering groundsel seeds.

Although soft leaves may be eaten by soil life before summer is over, and sometimes before fall or winter is over, they can have great smothering ability until they are eaten.  Many tend to lie flat over seedy soil and stop spring weeds like groundsel and bitter cress, even without extra leaves piled on.  Piling them 6 inches or more deep will preserve the top layers of leaves over the entire season, as they quickly dry out on top while the worms happily eat the damp bottom leaves.  But that’s a lot of leaves unless one wants to grow vegetables.  In that case, a foot is even better. 

Oak leaf mulch under a large oak

          Hard leaves, like oak and sweet gum, stick around the entire season, but tend to be stiff and fluffy, and thus allow seeds to grow through them to the light.  Again, it usually takes more than naturally falls under the tree to stop many weeds, particularly annual grasses with larger seeds.  Merely covering the ground is insufficient, especially with weeds already growing.

Pine needles naturally fallen beneath the tree.  

Pine and true cedar needles are good for covering other leaves to hold them in place and give a consistent, quiet look to one’s mulch.  They are also good for covering compost spread on top of soil or leaves to aid seed germination, when spread just thick enough to hide the compost seed bed.  Piled over an inch deep, they stop germination as well as other leaves, as they pack down fairly tight.  They can be used for path cover, but pine are rather slick and not suitable for slopes.  Flat or non-needle conifer leaves, like fir, incense cedar, redwood, and sequoia, are soft and decompose as fast as other soft leaves.

 Pine needles spread as mulch. They are much used in the South, going by HGTV.

          Six inches to a foot of leaves can grow big food plants.  But piling one kind of leaf too deep can occasionally result in slow decomposition and slow growth of plants.  A mixture of several kinds of leaves has more variety for the soil life to eat, more nutrition, and allows water to move down through the stack more efficiently.  It is important to spread them in layers and keep the surface relatively flat, so the water doesn’t just run off the top or around bundles of leaves.

          One can grow garden seeds in a thick bed of leaves if one spreads an inch of compost on top of the leaves and plants into and on it.  This even works on top of black walnut leaves and soil, keeping the seeds separated from the juglone long enough to sprout.  Compost also helps decompose leaves more quickly for early spring growth.  But it is not necessary for planting large seeds, like beans, corn, and squash, into the leaves.  Poke them in to where you can feel moisture for them to sprout in.

          But for non-food-growing areas, a mulch of leaves with several thin layers, each just thick enough to hide what is beneath, can provide maximum weed control with minimal leaves.  Use soft leaves on the bottom to smother and physically block seeds and small plants from growing.  Hard broad leaves can be spread on top of those to keep the sun off the soil all summer.  Pine needles go on top to keep the leaves in place and give a consistent, calming look to the landscape. 

Leaves work well for mulching beds and borders, but weeds in paths have to be controlled, too.  Just about any material one puts on a path will sooner or later become a seedbed for whatever lands on it, except for pavement, and even there, they will grow in the cracks and holes.  Organic path mulches must be renewed every year or so.  Gravel is a headache once it fills with seeds and dirt.

4 x 8 sand, surrounding beds.

 

But a half-inch of 4 x 8 sand, which is river sand screened ¼-1/8 inch, can let you defeat the weeds by bringing them up right away, so you can slide a scuffle hoe, AKA hula hoe, underneath their crowns and pull or cut them off their roots.  Rake out the weeds, and your path is cleared without bending.

The key to how 4 x 8 sand works is that, when particles of different sizes are disturbed, the smaller sift to the bottom and the larger end up on top.  Dirt and small seeds on the path are sent by hoeing and raking to the bottom, and rocks and sticks larger than the sand float to the top where they can be raked out or picked up and thrown in the bed.  Quarter-inch rocks dominate the top, and don’t stick to shoes.  When seeds sprout, their crowns form at the top of the sand, so they are easily cut off their roots.  Very young plants whose crowns are cut off their roots are killed, as they have no food in their roots.

Gardening is easy, if you do it naturally.