Eradicating Buttercups and Horsetail

Beautiful But Dangerous

As spring arrives, the garden fills with primroses, crocus, and daffodils. If you live on heavy clay soil, the garden may also fill up with buttercups and horsetail. It’s really quite fascinating that weeds this challenging are such beautiful plants. Lustrous buttercups hold up their golden goblets to the sun, their petals gleaming as though glazed with golden Chinese lacquer. Feathery horsetail rises in delicately textured turrets, its whorling fronds unfurling in the sparkling spring air. Why don’t we love and worship them?

Lovely as they undeniably are, these two weeds are the scourge of many a gardener, creating a great deal of frustrating work. This is especially true for those dealing with clay. True, the heavy clay soils so common in the Northwest are often quite nutritious, supporting a wide range of plants that appreciate being mucky wet in winter and bone dry in summer. However, unimproved clays can be tricky to work with, apt to promote root rots and various fungal disorders.

Weeding With Drainage

Interestingly, the answer to clay soil improvement is the same as the answer to sandy soil improvement: In a word, it is compost. Rake an inch of compost into your lawn each spring and fall and you will notice a marked improvement in turf health. Mulch your beds and borders with 2-4 inches of compost each spring and fall and you will see decidedly happier, healthier plants.

However, where horsetail and buttercups flourish, another problem must also be addressed. Improving the drainage on your site will help almost everything to grow better, from lawn to flowers and vegetables. The only plants that won’t enjoy well aerated soil are those like buttercup and horsetails that prefer heavy clay soils that are low in oxygen.

Adding Simple Drains

How do you improve your drainage on clay soils? In general, this involves adding drains of various kinds. Depending on your site and situation, you may want to make or improve a curtain drain around your house. You will certainly be well served by trenching out all pathways and turning them into French drains. French drains are trenches of varying depths filled with gravel of varying sizes, again depending on what local conditions demand.

Dig your pathway about 18 inches to 2 feet deep and 3 to 5 feet wide. (Or, more sustainably, cause all that digging to be done by others.) These excavated paths can be infilled with 1- or 2-inch gravel for the first foot or 18 inches, then topped with 6 inches of 3/4 minus crushed gravel. (This means the largest pieces are 3/4 inch, and includes smaller bits which help the gravel both to pack well and to drain well.)

Mound To Bring Air In, Let Water Out

Such paths will allow more air into your soil, improving root growth in nearby beds. To maximize the effects, elevate your plants by mounding all the beds and borders. This does not require tilling or digging; just lift your plants, rebuild your beds by adding topsoil and compost, then replant everything. (It’s a good time to divide crowded perennials as well.)

Sounds simple? Maybe yes, maybe no. In reality, this is only a simple process when you are making a new garden. It remains fairly simple in situations where all the existing plants are young and small. In gardens filled with an abundance of mature plants, mounding is no longer simple and you will probably prefer to do what you can with compost and drains.

Help For Mature Gardens

To help heal soggy gardens with mature but struggling shrubs, begin with the trenched pathway concept outlined above. In addition, add 2-4 inches of compost to all beds and borders in spring and top them off in fall. Next, find a nearby nursery that makes aerobically brewed compost tea like SoilSoup. These living teas are like adding manure without a shovel; they open the soil and return it to abundant life without involving back-breaking work.

Next, begin a monthly spray program for plants, lawn, beds and borders. As the soil life and health increases, you will be able to cut back your compost tea spray program to every other month, then quarterly.  You will notice as an added bonus that your roses will have clean foliage and your plants won’t be suffering from mildews and botrytis.

Boosting Lawn Health

To improve lawns where buttercups thrive, rake in compost as mentioned above and spray with compost tea monthly all year round. If you have big soggy spots that are wet all winter, this may or may not prove to be enough. You may also need to cut drains across the lawn, fill them with gravel, then cover them with soil and turf.

Battling Buttercup By Hand

In time, improved soil will bolster turf root growth to the point that grass will be favored over buttercups. In the meantime, a fabulous little weeding tool makes buttercup removal an active pleasure. Even  surly teens will enjoy popping strings of buttercups out of the soil with this cute little gadget.

Called a Japanese weeding fork, it consists of a 3-4 inch handle with a two-inch metal blade. The narrowly forked blade has a deep notch that is exactly the right size and shape for buttercup roots.This neat small tool pops out the buttercups with a flick of the wrist and is extremely satisfying to use.

Japanese weeding forks come with wooden or plastic handles and cost under $10. This is the perfect tool for removing buttercups that have insinuated themselves into a well-filled border, where larger tools would damage plants just coming into bloom. It’s also good for removing weeds from cracks in paving or stacked stone walls.

Cutting Horsetail

With horsetail, the rule is; cut, don’t pull. Every time you tug a piece of horsetail, the root scar stimulates the production of even more shoots. Cutting depletes the root, while pulling energizes it.