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 Weekly Weeder-- Spotted Spurge, a Constant Irritant

          Spotted spurge, almost blooming

          I liked spotted spurge before some customers decided that they didn’t like it and I found out that its sap can cause skin cancer if one doesn’t wear gloves while pulling it, and perhaps if one walks barefoot on it a lot.  It has rounded oval leaves ¼ long and 1/8” wide, dark green with a red spot in the middle, giving it its name, and insignificant flowers, with narrow pink stems.  It just lays flat on the ground for the most part, sometimes standing up 6 inches tall in shade, seemingly taking little food or water from other plants.  Back then, I figured that such low annual plants at least covered ground and softened the look of the garden.

Young spotted spurge, en masse

It is an annual and makes thousands of small seeds that seem to come up all summer long, and it maybe even grows back from its root if cut below the crown before it makes seed.  Being an annual, it gets ugly when it has made sufficient seed and must be removed at that point, which can turn into a real chore if it has been allowed it to grow all over.  If it is allowed to stay, it just gets in the way of blowing leaves out of paths and driveways, edges lifting and grabbing leaves in the wind of the blower.

          This was just one of the many weeds and volunteers that used to grow in my paths and made me think hard about finding a path-mulch that is easy to weed.  Flat wood chips are best at stopping weeds from growing for the longest time, well over a year, but seeds that fall on it eventually grow, and every one of them has to be weeded by stooping.  Every other mulch eventually becomes a seed bed, some right away, even if they smother the weeds and seeds beneath, requiring yearly re-covering with more mulch, which is not cheap in labor and material cost, and not practical in the case of heavier gravels.

          Then I remembered the hula hoe, AKA scuffle hoe for how it is used, and stirrup hoe for its shape.  I realized that 4x8 sand, river sand sifted to ¼”-1/8”, can be worked with a hula hoe, unlike wood chips, bark, or heavier gravel, pulling weeds or cutting them under their crowns, which grow at the top of the mulch.  Rather than stopping weeds by smothering, 4x8 sand mulch brings up seeds right away, allowing one to remove the resulting plants with a hula hoe and a rake with little stoop work.  This turns a yearly chore into a sometimes bi-weekly one, but allows one thereby to keep paths clean, which is a good, orderly look for any garden.  It should be used no more than an inch thick, however, or it is like walking on a beach.

Blooming spotted spurge

          But spotted spurge is one of the weeds that is persistent at coming back after hula hoeing.  These weeds grow quickly from seed to making seed, maybe a month, and are dropping seed before one knows it.  These are among the weeds that make me work the paths every other week or so in my yard and a few other places, and spotted spurge may be the most persistent of the bunch.

          In my mulch beds, it is easy to take these weeds out, as they easily pull from soft soil, but they are still persistent if allowed to seed, and they readily hide under plants.

                                                                                                                          

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