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.

Paying For Free Leaf Pickup

Jo Gro, our city’s composting operation, will soon be under the management of Republic Waste Services, minus the sewage bio solids that it was originally started to make use of.  Those will be hauled by Republic to Dry Creek Landfill to make methane for electricity generation.  The city will be running Jo Gro long enough to decompose the rest of their bio solids, and then lease the operation to Republic, who will run it as a regular composting service.

A pile of leaf bags on the street

 One might expect “free” leaf pickup to go away, since it was instituted to provide material for Jo Gro to help decompose those bio solids.  But leaves will be picked up by Republic and Southern Oregon Sanitation from the curb for free as part of their franchise agreements with the City, as they always have.  The only difference is that they will be free to take them to any DEQ-approved composter, to seek the best price for dumping. 

Such “free” leaf hauling was part of the subsidy for Jo Gro, but wasn’t counted as part of it, because it was being paid for, not by the city, but by the residents as part of the cost of our waste hauling service.  Jo Gro will apparently continue to be subsidized by hauling leaves for free, but Republic will be the single composter to benefit, while Southern Oregon Compost will have to compete without such a subsidy, against a composter who doesn’t use biosolids anymore.

The city does not like to compete with private business, and presumably does not want their monopoly franchisees to compete unfairly with other businesses as well.  There are other small businessmen, gardeners and landscape maintainers, who would haul yard waste for residents for a small fee, as well as contractors like Aspire, whom the waste services use to haul leaves and trimmings now.  Republic even has its own yard waste service that more people would buy if the free service stopped.

Maple and plum leaves spread as mulch on the border

Those who haul their own trash to the transfer station don’t pay for free leaf pickup, but they get their leaves picked up if they put them on the curb.  Everyone who pays for regular trash service must pay for leaf pickup as well, whether they use it or not.  This gardener uses leaves for mulch and picks up leaves from the curb for her customers, using them to stop weeds, so we have to pay for a service we don’t use and beat that service to the leaves we need.

Pine needles are much used in the Southeast for mulch

Leaves are not waste and should not be wasted on compost.  Before Jo Gro existed, the city encouraged the use of leaves as mulch.  Leaves are still the best mulch for stopping weeds, and we should use them for mulch, not compost.  The City should stop this franchisee subsidy of a single composter at the expense of landscape maintenance, those who do it, and our customers.

Unfinished work killed two girls

Kids play in a pile of leaves.  It’s so common, it’s a cliché in the funny papers every fall.  So normal that a dad was taking pictures of his daughters playing in one, without thinking about the fact that they were playing in the street.  So obvious that an 18-year old, still a kid but driving with her brothers, drove through that pile, not thinking about what might be in it.  She felt a bump, probably thought she ran over a big stick, and drove the few blocks home before having her brother check for damage.  This happened last week in Forest Grove on October 20^th.

Everyone was careless in this accident: the kids for playing in the street; their father for letting them; the girl for driving over the leaves; but first and most of all, the school district for leaving a pile of leaves in the street, an attractive nuisance that did what attractive nuisances do: attract careless youngsters into danger.

This is just one egregious example of the consequences of disconnected public landscape maintenance.  One worker piles up leaves and expects that a crew will be brought to take them away.  But no one is in charge of making sure that gets done immediately, and it can sit for days or weeks before it gets done, often after citizen complaints.

Businesses generally don’t leave basic landscape maintenance jobs like leaf cleanup half-done even for one day, much less over the weekend.  They have to look at it, and they expect their maintenance people to finish a job before they leave. 

Governments do so routinely.  Their properties are spread over wide areas; their workers are focused on their tasks; and their contractors are narrowly focused on their contracts.  No one is in charge of making sure that landscape maintenance gets done in a timely, professional manner.  Landscape maintenance is an afterthought, perpetually underfunded or not funded at all. 

Community corrections work crews are used for work like picking up and hauling leaves, but their time is limited, both per customer and per day, and each government only gets about a day a week.  When it’s time, they have to go, regardless of how much work they have done or have yet to do. 

Leaves don’t have to be piled in the street to be dangerous.  When they fall on the street and get slick, rotting in the rain, they are a hazard to walkers.  I have slipped on them; so has my daughter, walking to work in the early mornings.  Drivers skid in them too. 

          Residential property owners and residents are the worst for leaving their leaves to rot in the street.  Grants Pass doesn’t yet have a code forbidding leaving leaves on streets long enough for them to begin to rot.  Do we have to have somebody die from a fall, or hit by a skidding driver, to pass such a code?

Statistics Show Our County is Drying

This writer has asserted, relying on memory, that we used to have more summer rainfall in this area in the mid-eighties than we have now, and concluded that our tiered water rates are the reason, as we have been feeding the water cycle less as we save water to save money.  Grants Pass city staff have told us that we are using less every year, which has caused the city to raise rates to cover overhead, which is most of the cost of cleaning and delivering water.

An analysis of three decades of monthly summer rainfall totals for the 97526 zip code, from June 1983 to September 2012, shows that precipitation in July and August, our driest and hottest months, has fallen 0.09 inch per decade, from 0.41 inch to 0.32 inch to 0.23 inch. 

Average high rainfall for the two months, a measure of storm strength, has also fallen from 0.25 inch the first decade to 0.17 inch in the second, and 0.12 inch the third.   In the first decade, there were bigger storms on average in July and August, the middle of the irrigation season, than in June-August or July-September: 0.25 inch as opposed to 0.23 and 0.24 inches.  This reverses in the second decade: 0.17 inch in July-August as opposed to 0.22 inch with June or September included.  It proportionately drops more in the third decade, with 0.12 inch compared to 0.17 inch with June or September averaged in.

This fits well with the idea that irrigation feeds the water cycle and increases rainfall in the general area, particularly thunderstorms.  But some would blame this drop in rainfall on global warming caused by higher CO2 levels.  More heat doesn’t necessarily mean less rain, as monsoons and summer thunderstorms in particular are caused by heat sending moisture high in the air, but less rain almost certainly means more heat from lack of evaporative cooling.

Temperature records for the same three decades in July and August alone, show that the average mean mid-summer temperatures fell from the first decade to the second, from 71.4° Fahrenheit to 69.2°, a drop of 0.6 °; and it rose to 73.2°, a gain of 4°, in the third.  It looks like temperatures rose from lack of rain, but the lack was not sufficient to stop a general cooling trend in the second decade.

Since we started metering water and charging higher rates for higher use, both our water use and our mid-summer rainfall in Josephine County have fallen steadily.  Average temperatures during the same period have gone up and down over the decades, so the lack of rain is not temperature-driven, and is probably due to less irrigation in the City of Grants Pass and its surrounding areas, where many farms are no longer being irrigated because they are no longer being actively farmed.

 

Grants Pass Precipitation for June-September, 1983-2012
Summer Rainfall by the month,
averaged by season and decade	June-Aug	July-Sept	July-Aug
1983-1992	0.45	0.46	0.41
1993-2002	0.38	0.43	0.32
2003-2012	0.47	0.29	0.23
Monthly High Daily Rainfall
averaged by season and decade	June-Aug	July-Sept	July-Aug
1983-1992	0.23	0.24	0.25
1993-2002	0.22	0.22	0.17
2003-2012	0.17	0.17	0.12
Average Temps in July, August	high	mean	low
1983-1992	102.1	71.4	43.3
1993-2002	101.5	69.2	41.3
2003-2012	102.5	73.2	48.8
Data from weathersource.com,
analyzed and summarized by Rycke Brown
Gardening is easy, if you do it naturally.

Use Leaves; Don’t Lose Them

Black Walnut in a bank parking lot.  A good street tree, apart from its nuts, but they are better than plums.

The Grants Pass City Council has finally decided to get out of the cheap compost and wood waste disposal business and save about $200,000 a year.  Our sewage solids will be trucked to Dry Creek Landfill to become methane and make electricity.  The Jo Gro property will be leased to Republic Waste Services, where they will continue under that name, accepting wood waste and yard waste and making compost with the latter, but it will be without bio-solids or city subsidy, at prices Republic chooses.  This means that the City will also not be picking up bagged leaves for free this year.  It is unlikely that Republic will either, since they have to compete with Southern Oregon Compost, which certainly doesn’t pick stuff up for free.

Since the City will not be picking up leaves for free, this gardener will be not be either, but I will pick up loads for $1 per bag, 40 lbs or less, to use on my customers’ properties for weed control.  But I’d really rather that you use them on your own property to keep the weeds down.

Leaves make superior mulch for weed control because the top layers dry out quickly, and do not make a good seed bed until they become compost or worm castings.  Worms love leaves for food, and they and the soil are sheltered by them from freezing, drying, wind, and rain.  Two inches can stop most small plants and small seeds.  More can stop bigger plants and seeds.  But bulbs and established perennials will generally work their way through several inches of leaves. 

A foot of leaves will decompose more quickly when covered with an inch of compost, and allow vegetable seeds that are sprinkled or poked into the compost to grow into huge plants.

There are no leaves in this area that are not good for mulch.  The ones that people question, oak, pine and black walnut, are the best for weed control. 

Oak and pine are said to be too acid, but they are not acid themselves; they just take a full year to decompose.  Shade and summer watering cause acid soil by leaching away calcium; evaporation brings calcium back to the surface.  These leaves shade the soil longer than most other leaves.  But when they are piled deep, the worms eat them and sweeten the soil with their castings, resulting in good soil.

Walnut leaves, especially black walnut, are said to be herbicidal and kill plants.  But they are actually a pre-emergent herbicide that stops any seed smaller than a nut from coming up.  Starts and established plants are not affected.  Black walnut leaves are quickly eaten by worms and are generally gone by the end of spring, except for their long petioles.  But their pre-emergent effect sticks around all season.  To sprout seeds on black walnut soil, lay down an inch of compost and sprinkle them on.   To sprout larger seeds, spread another inch of compost on top of them.

9/20/2013  Published in News-You-Can-Use-by-Rycke.blogspot.com, and GardenGrantsPass.blogspot.com.

 Join Garden Grants Pass in free gardening classes at Greenwood and Schroeder Dog Parks; contact 

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

Gardening is easy, if you do it naturally.

Petition to the Grants Pass City Council: Change our water rate structure to promote irrigation.

A major goal of the City of Grants Pass is to “be a city that looks safe and is safe.”  Well-watered, well-maintained properties are pleasing to the eye and orderly, which looks safe.  Watered yards, plants, and misters also cool and humidify the area, and feed the water cycle through evaporation and transpiration, causing rain.

Unwatered yards are ugly even when mowed, and they too often are not mowed, because no one likes to maintain ugly.  They encourage litter, vandalism, and other crime.  They are hot and dusty in summer.  They are often a fire hazard as well.

Grants Pass once had unmetered water, and nearly everyone watered their yards and maintained them.  But now we have meters and tiered water rates that discourage water use, charging little per unit for a very low base and more per unit for greater use, in several tiers.  This has discouraged watering and gardening of residential, commercial, and public landscapes, and has likewise discouraged landscape maintenance. 

The vast majority of the cost of providing clean water is overhead in plant and people; very little of it is unit cost for cleaning and pumping.  Discouraging watering of yards has made the City raise rates several times to cover the loss of income from lower water use; the last time the city raised rates, you raised the base rate to stop making the water plant’s bad financial situation worse.

Gardening in Grants Pass has become a privilege of the middle class, the rich, and those willing to bear the cost of the water plant, which is borne by fewer people as more people stop watering their yards.  One can tell now, as we could not before, who is poor or cheap.

          Many poor people, especially our elderly poor, would like to better care for their yards, but it is hard to maintain a dry yard, even for those who know how, and even harder to make it pretty.  All of us would also like predictable, even monthly billing for water.

          THEREFORE, we, the undersigned voters of Grants Pass, respectfully request that the Grants Pass City Council change our water rate structure: Charge each household a flat rate based on the average household’s winter water use, sufficient to cover Water Department overhead; price the second tier at a lower unit cost sufficient to cover the City’s unit costs of providing water; and provide the third and top tier, presumed to be used for irrigation, cooling, and washing, at no cost.  Charge businesses an individual base rate based on each business’ average winter water use, as you do for sewer, accounting for much greater size differences and water use.

This is an advisory petition

You may sign this petition on Saturday at the Growers Market between 10:00 and 1:00 PM or contact:

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