The Weekly Weeder: Natural Weed Control

Notice the old leaves under the rose, and the 4 x 8 sand paths.

            Weeds are taking over neglected portions of our cities and countryside, making them ugly, disorderly and unsafe.  Flowering weeds are often ugly, always disorderly, and once they dry out, they are a fire hazard.  If not killed before going to seed, they spread themselves around; they are a nuisance that multiplies.  Whole city subdivisions have burned in recent decades, and some small towns as well.  Oregon, Washington and Arizona burn in the summer, California in the fall, and large expanses of the Great Plains in dry winters.  When city weed codes are well enforced, cities don’t burn. 

          The most dangerous weeds are annuals that seed and dry out in a season.  They make many seeds, some of which can last for years in soil before they sprout or rot.  But their roots don’t need to be pulled to kill them; all of their top growth comes from their crowns, the part of the plant between the roots and the top.  Cut them under the crowns, and they are gone.   

          You can cut them under their crowns with scissors or a knife, which is great for going after individual weeds, but is relatively slow.  Still, this is the best way to handle seeded puncture vine, a noxious weed that pops bike tires as well as poking bare feet.  Cutting or pulling are the only ways to take weeds out selectively in lawns, beds and borders.

          You can also beat the crowns out of the soil wholesale with a string trimmer.  This works best when the plants are young and not yet seeded, and the soil is relatively soft.  It has to be repeated to catch newly sprouted annuals and re-growing perennials.  Done often and long enough, it can kill out perennials as well.

          You can mulch with leaves, compost, wood chips or bark to smother small plants and stop seeds from sprouting.  Most very small seeds need a touch of sunlight to sprout, and nearly every newly sprouted plant can be easily smothered with 2 inches or more of dense mulch.  Avoid fine bark and non-sifted bagged bark with fines; bark’s natural preservatives leach downward and kill soil life. Larger barks do not kill soil, but ¾” nugget and larger bark are not dense enough to smother at 2” deep.  Walk-on fir bark is most effective at smothering and staying put.

          Leaves are the most effective mulch, though some tend to blow around a bit.  They dry quickly on the surface and make a lousy seed bed for whatever falls on them.  Leaves and compost also feed soil life, which makes the soil soft for pulling weeds and provides habitat for good bugs like soldier beetles, spiders, centipedes, millipedes, ground beetles, and earwigs.

          You can spread an inch of 4 x 8 sand (river sand sifted to ¼-1/8 inch) to bring seeds up and then cut under them with a hula hoe (AKA scuffle hoe and stirrup hoe), which is made to slide under crowns.  Sprouting seeds put their crowns at the top of the sand, making it easy for the hoe to slide beneath them.  This is particularly good for maintaining paths and open areas.  4 x 8 sand is also good for establishing lawns from seed, as it covers the seed, brings it up by warming the soil, and protects roots and crowns as they grow.

          Roundup herbicide (glyphosate salts) should generally be avoided, simply because it also fertilizes for broad leaf and annual plants and feeds worms and pill bugs, which in turn attract moles.

           

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

The Natural Gardener: Leaves build soil and stop weeds

Leaves are not waste and should not be wasted.  They are the best and cheapest mulch around for stopping weeds, building soil and providing food and habitat for predator bugs.  This retired Natural Gardener used to haul bags of excess leaves away for free to customers through the fall, spreading them to reduce work and help preferred plants grow for the rest of the year.  Now I am taking leaves for my own yard only. I prefer leaves in clear plastic bags.  I don’t take bags heavier than 50 pounds, or with too many sticks.

Nearly every other mulch is a seedbed as soon as it is spread.  Seeds fall on top, find a crevice and grow.  Leaves dry out on top, and so make a lousy seed bed for anything that falls on top of them.  Even a thin layer stops small seeds beneath them that need sun to sprout.  Two inches or more can smother most seeds as well as small plants and feed the soil enough to soften it and make it easier to pull the weeds that grow. 

The deeper they are laid, the more weeds they can stop and the more they build the soil and soften it.  A foot or more will grow huge vegetables, while they rot and worms and pill bugs eat them over the course of the gardening year.  That increased fertility can be maintained with only a few inches per year. 

The only thing comparable to leaves for building soil is compost, which leaves become without any special help, if they aren’t mounded.  A mound sheds water, within which leaves can stay dry and not decompose for years.  Spread flat, a foot of leaves is the equivalent of 6 inches of compost, which can also grow huge vegetables, plus can be used to build beds year-round.  In late spring and summer, exposed compost also dries out quickly, but in winter, it is a seed bed for whatever falls on it. 

You can start small cool-weather seeds by spreading an inch of compost on top of leaves and scattering the seeds in it; for larger seeds in late spring and summer, scatter seeds on the leaves and cover them with compost.  You can also poke large seeds like peas, corn, beans and squash into the leaves to where it is moist to maintain that cover of dry leaves while they grow.  You can plant starts into leaves as well, with or without compost on top.  

You can warm the leaves to help the seeds and starts grow faster by putting rocks around them.  Rounded river rocks, just small enough to move with one hand, are easy to move and hold heat through the night, when the plants need it most.  The smaller the rocks, the hotter they get but the less heat they hold through the night.  Larger rocks can be used to provide a solid edge for mulch beds and keep them from spreading.

Leaves should be removed from buildings, pavements, gravel, and paths.  They should be left and built up on open ground, in beds and borders, and mulch-mowed into lawns.  If you have too many, put your excess in clear bags and call me.

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

The Weekly Weeder: Whacking Weeds Can Work

          Whacking annual weeds can kill them, if you whack them low enough—right into the dirt, below the crown.  They have no means to grow without a crown, from which all their growth comes.  (Chickweed is an exception, as it does not have a crown and will keep trying to grow and set seed until it has made enough of it.)

          I saw weed whacking work several years ago, when the city or one of its maintenance contractors eliminated goat heads from the Wastewater Treatment Plant property for several years by repeatedly scalping the dirt where they grew with a string trimmer.  This year, they are blooming and seeding in their old locations near the back fence; apparently the maintenance contract has changed and the city’s institutional memory is short, but goat head seeds can sprout for at least 5 years and will come up all summer until frost.

          This year, I whacked the dense weeds along the irrigation ditch behind my mom’s house into the dirt in May, when they were still green and flowering, but hadn’t set seed yet.  A week later, I pulled a few that had been missed.  The next week, only the false dandelions had come back, and over two months later, that is still the case.

          Last week, I was pulling and cutting crab grass from the backyard below, and looking at the enormous quantity of spotted spurge growing along the same path, but not yet flowering, and asked myself why I didn’t just whack them all, as the annual weeds would be killed out, while the perennial grass and clover would come back from roots.  So I got my battery-powered trimmer out and started beating the dirt, working out which direction to work in order to throw the debris away from my legs and face.  The next week, that area was still quite barren.  This week, some were starting to grow back, and I whacked them again.

          I will have to repeat all summer and reseed clover in the fall, I am sure.  Spring weeds start in the fall and winter, flowering and setting seed around the same time in the spring, allowing one to kill them out for the season with one soil-scalping before they are ripe.  Some summer annuals, like star thistle, start together in spring and can be killed out as they start to bloom in early summer.  Most summer annuals keep sprouting through the hot weather, particularly where they are watered.  Goat heads have a final flush of sprouting as the weather cools in the fall, just as heron’s bill is starting its fall sprouting season.

What does not work to kill weeds, of any sort, is cutting two inches above the ground.  They continue to spread their flowers and ripen seed below the cutting height.  Weed control is seed control, and if the plants are still flowering, they are still violating our city code, which requires that one prevents flowering, seeding and noxious growth by cutting or killing.

                             

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

The Natural Gardener: Aphids on Roses are Good

          A couple of weeks ago, I saw a bad infestation of aphids on Betty Boop, my favorite rose.  I also saw some soldier beetles already on the job, eating them.  I checked them a few days later, and both aphids and soldier beetles were gone.

But I know that those soldier beetles laid eggs under the leaf mulch in my beds, and their larvae will be patrolling under that mulch for the next 10-11 months, eating any insects they can catch and kill.  They pupate and become adults in April and May and emerge, ravenous for aphids to make their eggs.

I learned this the spring after I bought my house, in 2000.  All the roses that came with the property were heavily infested with aphids, and I waited for weeks for lady beetles to show up and clean them up and make their young, who likewise eat aphids.  But the infestation just got worse, until I got nervous and decided to spray them with soap.  I was heading out there with the spray bottle in hand, when I saw about 50 soldier beetles flying around the most infested bush and mating—so I didn’t spray but I did look up these red and black beetles and learned their habits.  Within a few days, both aphids and soldier beetles were gone.

I had been waiting for lady beetles because, in Arizona, I had a single broccoli plant that was infested with aphids.  I had learned that aphids are specific for particular types of plants.  This being the only brassica in my garden, I knew there was nothing else that they would eat, so I didn’t pull the plant, wanting its seeds.  After a while, it became a lady beetle factory, feeding at least 100 of a several different sizes and colors of lady beetles, including young and pupae.

But here in Southern Oregon, lady beetles have to compete with soldier beetles, which, with their short adult life span, are more ravenous when they emerge from the mulch.
Later in the summer, I tend to have aphids on corn, which attract lady beetles in large numbers and don’t really hurt the corn.  They also do the same thing on sun flowers, though birds are more likely to eat them there.  A couple of years, I had large, grey aphids on my fringe pussy willows, which were eaten by hummingbirds, chickadees and woodpeckers.

Aphids are manna for predators that eat them, crowding together in large numbers for easy picking, full of sugar as well as protein.  Those that grow on poisonous plants, like hellebores, often are not eaten by anything.   I have seen soldier beetles eating aphids on hellebores, but only once, so I am more likely to spray them there.  But most of the time, they are useful to bring in predators that might stick around and eat other insects as well. 

But soldier beetles won’t lay eggs where there isn’t any mulch cover for their young.  Don’t use finely-ground bark, which leaches its natural preservatives into soil and kills everything in the soil but plants.  Coarse bark, like walk-on fir or nugget bark, can provide shelter and help keep soil moist, but the best garden mulch is leaves, which feed fungi and soil life and become rich soil.

         

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

The Natural Gardener, Gardening in March

          March has come like a white wolf in sheep’s clothing, with snow in the middle of a week of rainy weather on the 5^th and 6th.  Can’t garden until it melts, but unlike the storm in January, it is gone on the 7^th.  February didn’t have its usual two-week break of warm, sunny weather; there was some sun between the rains, but not a lot of warmth.  Daffodils barely started to open, when they are usually in full bloom by mid-month. 

          We are told, in this area, that we should cut back the roses when the forsythia blooms, but as often happens, roses have broken buds and are leafing out well before the forsythia even breaks a bud.  This gardener crowned most of her roses before the end of February, though there remain two customers who haven’t been served yet.  Not to fret; growth is slow and little will be lost in waiting another week or two. 

We cut roses back to the crown, the hard knot of wood at the base, rather than the usual foot tall, because black spot grows all over the stems, and will just re-infect the leaves if any stem is left on the crown.  Nearly every rose in town has black spot due to our mild winters, though Rosa rugosa is pretty resistant.  This is not the only time one can crown a rose.  A rose crowned during the spring growing season will come back to nearly full height and bloom within a couple of months.  Crowned in summer, it will grow back and bloom even faster in the heat. 

March has the equinox, the day and night of equal length, on the 20^th.  One can plant cannabis clones or seed outside after this date, and they will not bloom prematurely as long as one does not deprive them of the increasing day length before 6 weeks after planting.   The way to do that is with a “light depo” or light deprivation house, in which one pulls a cover over the plants to give them only 12 hours of light, which starts them blooming heavily and makes their buds more solid.  These are being advertised on the radio and elsewhere.  

This year, it may pay to wait a little longer to plant, for sunny weather to warm the soil up, as your clones or seedlings will be eaten by bugs if they are planted in soil too cold to get them growing.   The same goes later for regular summer food crops; if bugs eat your plants, replant.

But now is a good time to plant peas, potatoes, onions, lettuce, spinach and other greens, preferably from seed or bulb.  Pansies and petunia plants are in the stores and will be happy in the chilly ground.  Cyclamen and hellebores are blooming and will be available at the Growers Market this month.

Blueberries at Sandy's Nursery.  Southern "Legacy" are on the right, with leaves.

It is time to plant blueberries, which are available now at Sandy’s Nursery in #2 pots.  They have included one variety of Southern, Legacy, with their usual Northern varieties.  Southern blueberries take our hot Southern Oregon summers a bit better than Northern varieties; they keep most of their leaves through the winter and will drop them after they bloom and new leaves grow.  Their branches are thinner and their leaves smaller, and they often turn colors through the winter.

Keep in mind that blueberries want to be planted in very loose, rich soil.  If yours is not loose enough to dig with your gloved hands, put the plant on top of the ground and surround it with compost to the top of the roots and at least 3 feet wide.  Unlike most other potted shrubs, blueberries will sink into the soil as the compost around it is worked in by worms, rather than being left high and dry.  

Their spongy root system does not grow deeper than about 6 inches for about 5 years, when they put down a deep taproot for water.  To grow big blueberries before that, run a mister near your plants through the heat of the summer to keep them happy, and always keep their roots covered with coarse bark, straw, or hard leaves that will stick around, like oak leaves or pine needles.   They want full sun and their feet well covered and cool.

         

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

The Natural Gardener: February Gardening

          February in Grants Pass is when the garden and the gardener really start to wake up.  January has its snowdrops, but we don’t really care; it is too cold and dreary to draw us outside.  In February, sunny days get warm enough to make cold weather gear too warm by afternoon, and coax crocuses and daffodils to bloom.

Daffodils in oak leaf mulch for weed control.

February is the time to kill annual springweeds like bitter cress, heron’s bill, groundsel, foxtail and cheat before they bloom and spread; it has been since October, when they started to grow and some started to bloom.  Cut any annual weed under the crown and it will be gone; you can clear a lot of them quickly with gardening scissors or a knife. 

Winter is also time to cut and dig rampant perennials like violets that are in stasis until this month, when they will start to bloom in earnest, set seed and make the matter more urgent.  Cut blackberries back and dig out their crowns.  Dig excess raspberries, transplant them, and prune out dead canes.  You still have time to transplant trees, shrubs and perennials while roots grow before spring top growth begins.  Winter is the best time to do heavy tree pruning with a saw, but lopper work is better done in midsummer.  "Crown" your roses when their buds start to grow, cutting them to the hard crown at the base to stop black spot until fall.

It is also time to start new gardening beds with compost, edging the beds with 6-12” boulders, choosing rocks with flat bottoms from the pile at Copeland.  Leaves can be used in the fall, several inches to a foot thick.  But new beds can be started at any time of year with compost.  One can build compost beds in the heat of summer for summer vegetables and fall perennials, or in the depths of winter for winter and spring planting.  Two inches is good for ornamentals, but six inches will give them a better start and grow great vegetables. 

Compost needs to be covered with coarse mulch like walk-on fir or nugget bark to protect it, roots and seedlings from rain, wind, and drying sun.  Avoid using fine bark, which kills soil with its natural preservatives. 

Blueberries and azaleas don’t even like to be planted into plain soil; they do better set on top of the ground and surrounded by compost covering their roots; their fine, spongy roots will sink into the soil as the compost is worked in by worms.  The more general rule is that #1 pots and larger need to be planted in soil, or they will be left high and dry as the compost is worked in and rots, while 4” and smaller pots will sink into soil with the compost.

          Paths need to be controlled too.  Two inches of wood chips, walk-on fir or ¾ inch nugget bark, will stop most weeds for a season, but need to be refreshed yearly.  4 x 8 sand, ¼-1/8 inch sifted river sand available at Copeland, laid one inch deep, covers mud and makes it easy to hula-hoe and rake young weeds as the sand brings them up.  (It also is good for starting a lawn and covering its mud.)  It is also easy to clean 4 x 8 sand by blowing and raking the tree trash into the beds for mulch.  Some trees, like mimosa, demand it, as they drop sticky flowers half the summer, leaves in the fall, and seed pods all winter, none of which are easy to clean off bark or chips.

         

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

The Weekly Weeder: Prime time to kill spring weeds

          This year, I am concentrating on weeding out heron’s bill and other spring-blooming weeds through the winter, after spreading leaves in selected locations all fall to try to smother them out.  This year, most of them got started in the fall before falling leaves were even available, as we got early cool rain.  Even then, most of the bags of leaves could not be spread while gathering truckloads of them; I was gathering piles of bags for me and my customers while the getting was good and am still spreading them on one property.  A lot of weeds got smothered; some will get through.

          Today, I will be cutting heron’s bill out of Schroeder Park’s tent campground, where it is fairly easy to weed from the silty ground, there being little perennial grass for it to hide in there.  While I’m at it, I will be pulling groundsel, which is already putting out flowers and seed in many places.  Over the summer, the main target was goatheads, but I was cutting heron’s bill then, too, brought up by cooling irrigation water in late summer.

On February 4^th, there is a “Weed Wrangle” in Griffin Park, starting at noon.  It is focused on pulling out Scotch broom, an invasive evergreen perennial shrub that is a great fire hazard.  It appears that they will be demonstrating the Uprooter, an amazing tool for pulling out shrubs.  But my focus will be on heron’s bill on the downriver side of the boat ramp, where I was cutting goat heads this summer.  There were young heron’s bill down there then, but I was concentrating on the goat heads, knowing that the heron’s bill could wait until now; it is not yet blooming.

Another target this time of year is bitter cress.  I used to wait until it and many other weeds flowered to pull them, because that is the easiest time to pull them, as the flowers show them up; their stems are strong; and the root is reduced and pulls right out in most cases.  But they are numerous; they all want to bloom close to the same time; and they tend to disappear into the greenery once their little white flowers are done blooming, until they ripen and start popping seeds, when they turn creamy yellow-white and show up bright and ugly, too late to stop the seeds from spreading. 

So I’ve learned it pays to pay attention to them and other weeds before they flower, and cut them as I see them, under the crown, from whence all growth of annual weeds comes.

                             

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