Leave leaves on your lawn

Just enough leaves on a lawn to stop weeds but not good grass

People are way too afraid of leaves on lawns.  Perennial grass is stronger than you might think.  A pile of leaves will leave a hole in a lawn.  Two inches or more will allow grass to grow through only here and there.  But a few layers will not stop perennial grasses from jumping right up in the spring.  They have enough food in their roots to push through light layers of leaves.  Leaves keep the soil warmer than no leaves and make it more fertile as the worms eat them through the winter, so grasses grow stronger in the spring.

Leaves not only feed soil and keep it warmer to grow grass better, but they stop small seeds like crabgrass; annual rye; Bermuda grass, nut sedge; dandelions; wild lettuce; and groundsel, the first of the wind-blown weeds to bloom in the spring, by keeping sun off the soil.  They also stop mosses, which like these weeds, need sun on bare soil to germinate.  Large annual grass seeds, like cheat and foxtails, can push through a few layers of leaves and need to be pulled.  You can tell them from perennial grass sprouts by their color, which is a lighter green with wider blades than perennial grass, or by their seed stalks later in the spring.  Crab grass, which sprouts in late spring, are very fat even when very short, and are best pulled small.

The weakest perennial grass is probably perennial rye sod, which most lawns on new construction are built with.  It is not a true sod grass; it is a clumping grass held together by plastic net.  Its roots are short for cutting off its clay soil base and transplanting, so it only lasts about 5 years before being invaded by stronger grasses.  Clumping grasses don’t spread by rhizomes, underground stems, but depend on reseeding to refill bare spots that form when clumps die, so it pays to reseed it in the fall before allowing leaves to cover, or rake it into the leaves in spring.  Its seeds are large enough to push through a few layers of leaves when they are ready to grow.  Perennial rye seed grows deeper roots than rye sod, and can create a stronger lawn as the sod grass dies out if it is reseeded yearly. 

Perennial grasses prefer to grow longer north of California, as the sun is lower and they need to be taller to catch the sunlight.  Two inches tall is good in summer, but 3-4 inches is better in winter.  Not cutting grass too short in summer or winter also helps keep sun off soil to prevent weeds and moss. 

A mulching mower can break up the leaves and help them to lie heavy enough between the grasses to keep small weed seeds from sprouting, but whole leaves will not stop the good grass from growing from roots or seed if they are not too thick.

Use leaves to stop weeds

Oak leaves covered with pine needles to keep them in place

Leaves are starting to fall, and they are way too useful to just rake up and put on the curb for pickup.  It’s also a lot of work to rake them out of your shrubbery and flower beds.  Leaves are natural mulch that feed soil and stop weeds, and the thicker they lie, the better they do it.  A foot of mixed leaves can grow great vegetables. They belong on bare soil and mulched beds. 

Leaves laid thick for growing vegetables

Leaves need to be removed from buildings, pavements and paths.   They should not lie too thick on lawns, where they can smother grass, but even there, they can suppress crab grass and other small seeds, while stronger perennial grasses like fine and tall fescues, can grow right through several inches as the soil warms in the spring; they are encouraged by the fertility.  Larger annual grasses, like cheat and fox tails, need a good two inches to stop them.
Most small seeds need a touch of sunlight to allow them to germinate, lest they sprout too deep and are unable to grow out from under their cover.  The larger the seed, the more food it has to grow through soil or leaf cover.  But the smaller the seeds, the more there are to sprout.  Once larger seeds have sprouted, it can be easier to smother them with mulch, if they are covered before they put a lot of food in their roots.

Naturally fallen Red Maple leaves stopping bitter cress and annual rye

Leaves vary in their ability to stop weeds from sprouting.  Very soft light leaves, like box elder, can be eaten by worms, pill bugs, earwigs, and other detritus eaters before fall is even over, and are good for feeding soil, but are fairly useless for stopping weeds in the spring.  Not-so-soft leaves, like red maple, will make it through the winter and stop early spring weeds like groundsel and bitter cress.  Tougher leaves, like oak, sweet gum, and magnolia, stick around all summer, and prevent the germination of later-flying wild lettuce and dandelions and tracked-in crab grass.

Non-broadleaf evergreens also vary in their ability to stop weeds.  Pine needles and needle-type true cedars are tough and take a long time to decompose, but their shape allows seeds to grow through unless they are over an inch thick.  Flatter evergreens, like fir and local cedars, decompose more quickly, but seem to stop weeds fairly well anyways.

One kind of soft leaf can stop weed seeds smaller than a maple nut all summer, even after they are gone: black walnut.  They have juglone, a natural pre-emergent herbicide.  They are not a problem for established perennials, but they stop smaller seeds even after the soil is bare.  Spread under a tree where birds perch, they can stop blackberries and other berry seeds from sprouting where they are laid at least an inch deep.

Use leaves; don’t lose them.  They can save you a lot of work.

October issue, online at GardenGrantsPass.blogspot.com, sold at the Mail Center, 305 NE 6^th St. 

Gardening is easy if you do it naturally.  Litter is tagging, marking the territory of the disorderly.

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

Keep food and drink cool with water

You can keep food and drinks cool on a camping trip or in an emergency without ice or a refrigerator, using the powerful cooling ability of water, which evaporates at 41 degrees, and therefore can cool stuff to 41 degrees, regardless of air temperature, as long as relative humidity is not 100%.

Take a jug of water.  Put it in a shallow pan.  Cover it with a towel, and let the ends of the towel lie in the pan.  Pour water over the towel and fill the pan.  The water evaporates from the towel, which wicks more water from the pan, cooling the towel and the mass of water beneath it eventually to 41 degrees F, the point below which water stops evaporating.   Theoretically, one could cool a box of food by setting it in a bigger box and covering it with a wet towel that lies in water in the larger box.  I cool and keep grapes and melon slices fresh, moist and free of flies by covering their bowl with a wet towel set in a shallow pan of water.

One might think that standing water would likewise cool off to 41 degrees, because it evaporates.  But it has a smooth surface with surface tension, allowing relatively little evaporation compared to a towel, which has a rough surface with lots of surface area to evaporate from, and no surface tension.  Towels are made to suck up and evaporate water efficiently. 

Standing or flowing water also sucks up heat from the mass that it is sitting in or flowing over and holds it in its mass, so a low-running creek or river or standing water can get warm, because it does not evaporate faster than it soaks up heat. 

The water cycle that makes summer thunderstorms depends on evaporation and condensation.  We used to water most of our in-town properties and most of our farmland back in the '80s with sprinklers, and we had frequent wet storms in midsummer, more frequent and stronger uphill and upstream in Jackson  and Klamath Counties, keeping our creeks running. 

In the ‘90s many cities started raising water prices to save water, regardless of local supply or costs.  Drip irrigation and letting lawns dry came into fashion.  Watering plants with drip saves water at the price of losing the evaporative cooling effect of wet plants and soil, and thereby reducing the water cycle that makes summer rain.  Letting land go dry stops most transpiration from plants, and makes no rain.  Half or more of our town and farms are dry.

Now we get more dry storms and forest fires, and creeks going dry that used to run year-round. We have lost nearly a tenth of an inch of midsummer rainfall per decade for the last two decades.  Our July and August storms used to be larger than those in June or September.

September issue, published in GardenGrantsPass.blogspot.com, sold at the Mail Center, 305 NE 6^th Street

Gardening is easy if you do it naturally.  Water is not precious; it overpriced.

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

Good mulch brings good bugs

Leaves under butternut squash and tomatoes

A gentleman of my acquaintance asked me what to do about squash bugs.  I said that I never really have a problem with squash bugs.  Turns out that the people he is helping with their farm are using plastic mulch to control weeds and row covers to try to control insect pests. 

I pointed out that what controls bad bugs are good bugs, predators that eat the plant eaters, and the most effective ones require good mulch like leaves to live under.  When you have plastic mulch or bare soil, you lose all the spiders, centipedes, ground beetles, and soldier beetles, to name a few of the most effective predators in the garden.

Warming rocks under peppers.  They warm the soil at night, cool it during the day.

Almost all of these predators live exclusively under loose mulch and rocks.  Soldier beetles spend the spring month of their adult lives flying, eating aphids, mating, and laying their eggs under mulch, where their larvae live under the mulch the remaining 11 months of the year, eating anything they can catch and kill.  If you have no loose organic mulch, you will have no soldier beetles laying eggs, and few or none of the others.

He said that the plastic mulch is needed to keep weeds down.  I said that leaves do that.  Not only do they keep sun off the seeds that need light to sprout, but they are a poor sprouting surface, as they dry out quickly, so seeds that land on top cannot sprout either.  Only larger seeds can get through 2 inches of leaves, and they are easily pulled; it is the tiny seeds that need sunlight on soil that are hardest to control without mulch.

4x8 sand and rocks under peppers and melons.  Insects are not under sand, only under rocks.  Sand is too hot.  Walk-on fir bark is beyond.

Plastic mulch cannot feed soil, while leaves are the natural food of worms and other detritus eaters, who turn them into soil.  One eater of detritus is the earwig, which many think of as a pest.  They are rather creepy in their habit of hiding in flowers and foliage during the day and coming out when they are brought into the house, but they don’t generally eat live plants; they eat the fungus out of dead or living leaves and can actually eat fungus, like rust on hollyhocks, out of your plants. 

Wikipedia considers earwigs omnivorous and says that they eat insects and plants.  Scientists seem to have missed that they love the fungus-infected parts of leaves.  They are said to eat corn silks as well, but I always have many earwigs and no corn silk damage.  Without fungus-ridden rotting leaves to eat, earwigs have only the softer parts of live plants to eat.

Two inches of leaves is great for stopping weeds and feeding soil.  12 inches or more can make wonderful soil and grow huge plants as they decompose.  Start next year’s garden by gathering your leaves this fall, rather than giving them to the trash company for compost.  They will make wonderful compost in your garden if you just let them lie there, and add to them.

Control Cobweb Spiders with Mist

The "cellar spider," family Pholcidae, is our most common local cobweb builder and the one referred to in this article.  They grow up to an inch or so across.  Black widows and their relatives are more commonly considered cobweb spiders, going by the Internet.  

Cobweb spiders have hatched, and are dirtying houses with their dirty little webs.  Unlike other web builders, a cobweb spider doesn’t clean and repair its web; it camps until the web gets dirty and then moves on to another spot, the homeless vagrant of the web-spider world.  A dirty, visible web is useless to the spider, except to steer flies into its new, invisible web.  But they sure mess up a house, inside and out, and shrubbery as well.  Cobwebs scream neglect to thieves and encourage other disorderly conduct, like littering and breaking windows.

Last summer’s fires were very hard on cobweb spiders and other web builders, showing up their webs with ash.  Cobwebbers starved except under cover; they could not build new webs fast enough, though they sure tried, covering shrubs all over town.   There have been relatively few cobwebs this spring until now.  

Daddy Long Legs, AKA harvestmen, family Opiliones, are not spiders, having one body section, not two.

Daddy long-legs have become common where they were rare, as they don’t build webs, but just walk around.  Cobwebs certainly mess up their hunting range, and could be a hazard to them.

Rain is also hard on cobweb spiders, because they are delicate, and too much water can stick their legs together.  Rain also shows their webs, so they build webs under cover until the weather is dry, when they spread into the shrubbery.  This is another good reason to use sprinklers rather than drip or soaker hoses, besides making rain.

A customer’s neighbor in her duplex has rough siding covered with tiny, dirty spider webs, with larger webs under the eve on his front porch, but she had few on her portion of the duplex, and she has needed little web cleaning thus far this year. 

This standing mister usually sells around $10.

Last year, during the fires, she started using misters to keep her plants happy, settle the smoke and breathe easier, and she has loved the results.   When they are on, it takes only a few minutes for them to show all the webs within 8 feet, allowing this gardener to clean them off with a web duster. 

There are many brands of this tool available on the web.

A web duster, a pom-pom shaped broom head that can be attached to an extendable pole, is also needed for cobweb spider control, since as soon as the misters are turned off and the webs dry out, they are good for catching food again, and the mist doesn’t reach to the high eves.  Using a duster alone, it is an endless battle to keep the cobwebs down.  The two together can do wonders.

If you don’t have misters, cobwebs in shrubs are better controlled with hoses and spray nozzles that adjust from spray to jet than with a web duster.  Or you can use a sprinkler and web duster.  But the jet reaches inside the shrubs where you can’t see.

Kill crab grass, goat heads, and star thistle

Crab grass didn’t used to grow in Grants Pass when I lived here in the 80’s.  Neither did goat head, known locally as puncture vine for what it does to bike tires.  Star thistle was out in the country on neglected farms.  Now we have all three all over town, the last two mostly on business, government, and vacant lots; people mostly don’t tolerate them around residences.

          All three can be hard to pull, but are easy to kill with a good pair of gardening scissors.  Kengyu pruning scissors are the best.  They are super-hard Japanese steel.  They can cut through dirt and gravel and still cut branches; they slowly wear down, but they don’t knick.  They may lie outside and get surface rust, but it wears right off with use.  They can not only cut weeds out of gravel; they can cut weed crowns out of cracks in pavement.  They can be found online.

          Any annual weed can be killed by cutting it off under the crown when it is blooming.  You don’t have to get the root; it has no food in it at that point.  Once it flowers, it has put all of its energy into its crown and above.

Green crab grass with dry foxtails and cheat

Young crab grass, spreading variety.  Some stand tall.

          Crab grass (Digitaria) likes water, but it can live on dust and dew.  It is related to Bermuda grass (Cynodon dactylon), with the same fingered seed head, but no underground rhizomes.  Where it has not been watered well, it has just enough root to hold it in the ground and pulls easily.  Where it has had good water, it roots deep and hard, and roots along stem nodes as well, the opposite of most annual grasses, but crab grass acts more like a tender perennial, and doesn’t die until frost.  Its roots are thin, tough and wiry, and don’t pull when mature and rooted deep.  Cut them off though, and the plant is gone; they have no food storage.

Goathead leaves and bloom 

Goat heads in bloom

          Goat head, Terrestris tribulus, literally “ground trouble,” crawls along the ground in a spreading mat with inch-long divided leaves and ¼” five-petal yellow flowers that open with full sunlight.  It laughs at mowers, spreading its tack-shaped seeds on their tires.  Also called tack vine, puncture vine, caltrops, and other names not suitable for print, its seeds can puncture bike, wheelbarrow, and some trailer tires.   It grows well in wet or dry ground, in bare soil or thick grass, spreading up to 3 feet across.  But its crown can be cut off its root, and the root will die.

            Yellow star thistle, Centaurea solstitialis, can be seen taking over vacant lots around the newer parts of town, its bluish foliage standing out among the drying grasses.  Its spines are only on its flower buds and fold down when they go to seed, but they are enough to declare it a noxious weed.  It doesn’t spread its seed on the breeze like other thistles, but on animals, lawn mowers and landscape maintenance workers; they cling to the plant all through the winter, long after the spines are gone.  It loves dry ground, but contrary to rumor, it can take heavy watering and come up through considerable mulch.  Mowing just makes it eventually seed out beneath the blades.  But its crown is often several inches above the soil bent sideways, handy for cutting off its root.

Cool off and Make Rain with Misters

Our snowpack is low but Lost Creek reservoir is full and Applegate is at 90% of capacity.  Nonetheless, Josephine County has been declared to be in a drought emergency, though the Rogue River, from which Grants Pass gets its water, is unaffected because our reservoir is full.  The hot, dry heat of a Southern Oregon summer will soon be upon us, and if we don’t get rain with our thunder and lightning, we will have forest fires and fish could be dying in the Applegate by fall.

So those of us who take our water from the Rogue should use it to keep our plants green and make rain.  It’s not like we could save it and send it to the people who are in the drought areas.  The only way we can share our water is by using it for irrigation, helping the water cycle to make rain by throwing it in the air, on the plants and the ground, and sending water vapor uphill and upstream on the prevailing wind to condense in the top of our water shed, or right on our heads when thunderstorm conditions are upon us.  Drip cannot do this, wash dust off your plants, nor water your plants half as well as sprinklers.

But one should use sprinklers only as much as necessary to keep one’s yard watered:  deeply and weekly.  It wouldn’t do to keep it running all day every day, though some did just that to keep the smoke at bay last summer.  But that gets expensive, breeds crane flies that eat grass roots, and makes a swamp that can be hard on plants.

Misters, however, can be run all day, every day and even all night, adding water directly to the air without greatly wetting the ground.  In our hot dry summers, plants, animals and people breathe easier with a little added coolness and humidity.  When smoke was choking us last summer, misters made a big difference in breathability, grabbing the smoke and taking it to the ground.  I could smell and feel the difference when I got home.

You can set up a mister system to air condition your yard with $10 misters that are often in stock at Diamond, the Grange, and Grovers; cheap ½” garden hoses; ½” male and female hose repairs; and hose Y’s, running them in a line around your front and back yards.  You want a hose running along with Y’s in it, and 15-20 foot hose lengths running to each mister from the Y’s.  1/2” hose is best because it has a smaller cross section than 5/8” but is the same strength of hose, so it doesn’t blow up and sometimes blow out under the pressure needed for misting.

Blueberries, which like their roots cool but their heads in full sun, do particularly well under the influence of mist.  Spider mites, which like dry and hot, do not love mist, so it’s good to use one in your greenhouse as well.