Weekly Weeder: Start stopping spring weeds now

Groundsel has yellow, nodding flowers and bitter cress has tiny white, erect flowers.

          Fall has barely started, but spring weeds are already growing.  Now through spring is the best time to kill them.  Cheat, foxtail, heron’s bill, groundsel, bitter cress, cleavers and many others can most easily be killed in the months before they start blooming.  The earlier you get to them, the easier it is.

Heron's Bill, starting to bloom in the spring.  It takes a lot of mulch to smother it at this point.

          You can kill them three ways: by smothering with mulch, preferably leaves; by pulling them out; or by cutting them below the crown, the point from which roots and leaves grow.

          Smothering with mulch saves you the most work in the long run, in the places where you can mulch.  Leaves, when spread 2” or more deep, can stop weeds that haven’t even started yet and those too small or too crowded to be worth individual attention.  Tiny seedlings can grow through a few layers of light fluffy weeds, but more than that can make them run out of food before they find the light.  Blocking sunlight on soil can stop seeds that need sun on soil from sprouting at all.  And leaves make a lousy seed bed for seeds that fall on top of them because they dry out quickly.

Leaves covered with pine needles, which hold them in place.

          But not all leaves are created equal.  Some are eaten by worms before fall is even over, some by spring, some stick around until midsummer, and some have to lie around decomposing for a year before even crazy snake worms will touch them.  (If you have no soil life because fine bark has killed it all, it may take a year or more for even soft leaves to go away, but that’s a subject for another column.) 

Fallen red maple leaves stopping groundsel and other weeds 

          Hard leaves, like oak, sycamore, sweet gum and magnolia, tend to be stiff and fluffy and take a few more layers to stop weeds from growing through.  Many medium and soft leaves lie flat and can stop weeds from sprouting with only a single layer, but will be gone before summer weed seeds start flying.   A mix of hard and soft leaves 2 inches or more deep will stop most small seeds and plants from growing, and feed and soften the soil to easily pull the ones that get through.  2 inches of leaves in the fall is enough to keep flowers and shrubs fed and happy, with loose, easy-to-weed soil that is protected from rain and sun.

A foot or more of leaves will grow big vegetables as they decompose.  For small seeds, spread an inch of compost on top and plant on it.  Large seeds and starts can be planted into the leaves without compost, allowing the leaves to stop weeds from sprouting on top. 

Cheat, blooming en masse, at the point when the roots are shrinking and it is again fairly easy to pull.

Annual grasses, large and small, are most easily pulled from 3 to 6 inches tall.  The longer they grow, the more roots they hold the soil with and the harder they are to pull.  Annuals cheat and foxtail are a lighter green and have a softer texture than perennial grasses, are often fuzzy, and grow in clumps, without runner roots.  As they send up seed stalks in the spring, they use up their roots and are more easily pulled, but time is then short to pull them all.

Most taproots are more easily pulled when the ground is wet, but some in rocky or very hard soil, or with soft stems, won’t pull and must be cut under the crowns.  This will stop most annual weeds and many perennials, but some perennial taproots, like dandelion, dock, and creeping oxalis, need the soil to be loosened with a tool and pulled eventually.  Some, like oriental poppies, can grow back from a root tip deep in the soil and take several years to get rid of completely.

                             

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

The Weekly Weeder: Queen Anne’s Lace is Wild Carrot

          The bright white umbels of Queen Anne’s Lace, AKA wild carrot, are decorating our roadsides and fields in many places.  These biennials are a bit harder to get rid of in their first year than annual weeds, because they have a large root that holds a lot of food for living through the winter and growing their flowers in the second year.   But once they put up flowers, they can be cut under the crown like annuals and they don’t seem to return.

          If the ground is recently watered, one can usually pull the plant at any point in its growth, especially if the soil is soft from mulching.  I only started cutting plants under the crown when I wanted to kill weeds like goat heads and star thistle in dry, unimproved ground.  But I have found scissors to be useful even where I can pull plants, as it is often quicker than trying to get a good hold on the leaves and crown and pulling, and one avoids pulling off the leaves and leaving the crown.  But in good ground, it can often be much faster to just pull weeds.  I go back and forth, depending on the plant and stage of growth.

          Wild carrot is the reason that it is better to buy carrot seeds rather than grow them, because they readily cross-pollinate and revert to the thin, white root of the wild plant.  If you buy those “rainbow” carrot seeds of many colors of root, they are even more likely to revert, just pollinating each other.  I did that once; they all turned out white.  If there are wild carrots within a half-mile, bees can cross-pollinate them with your carrots.

The tiny white flowers in carrot umbels are good for tiny predatory "good" insects to eat from.

          Looking at a prospective customer’s yard yesterday, I was reminded of one reason to let some carrots flower: to provide tiny flowers for tiny predators to get nectar and pollen.  You can actually buy exceedingly tiny wasps, for instance, that lay their eggs inside caterpillar eggs, but if you don’t have tiny flowers for them to eat from, they won’t stick around and lay eggs.  She was aware of the way these plants can take over and is planning to dead-head them to keep them from spreading.  This is also a good reason to grow chickweed in the spring; carrots don’t bloom until mid-summer.  Chickweed tends to stay in particular places and is a good eating green in the spring.

          A good reason to scatter domestic carrot seed all around your garden is to keep the pill bugs and sow bugs from eating your newly sprouted seeds.  They love carrot seedlings, and will eat them first.  This takes a lot of seed, which is expensive to buy in little packets, but Peaceful Valley Farm Supply (groworganic.com) has carrot seed in ¼ pound packages for a little over $20.  Freeze the seed and you will have carrot seed to scatter for years.

         

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