How to get rid of horsetail // equisetum??

Asked May 21, 2018, 1:52 AM EDT

Hello. I have just bought a home on a tidal creek and have horsetail everywhere. It's not getting tall in the lawn, on account of mowing, but I do see it on the creekside of the fence (not my property) but I know it spreads through spores and I think that is why I have it on my property. There are only a few beds on the property, but in addition to plants I want, you guess it, horsetail. HOW do I get rid of this stuff. I think I remember that you aren't supposed to pull it, but I also don't want it to keep growing. Also, do hydrangeas make a good planting here? If so, are some better than others? Thanks!

Clatsop County Oregon weed issues horsetail horticulture

1 Response

Horsetail, (Equisetum arvense L.), belongs to a prehistoric plant family that was dominant in the world 230 million years ago and significantly contributed to the formation of coal deposits. The Pacific Northwest is home to about 20 Equisetum species. Horsetail is a perennial plant that grows from underground tuber-bearing rootstocks. It is unique in that it has two types of stems and growth habits. Field horsetail does not produce flowers or seeds. For reproduction it relies heavily on its extensive, creeping root system and to a lesser extent on spore production. Fleshy tubers arranged at joints of the deep-penetrating rhizomatous root system store energy reserves (carbohydrates) and provide the plant with a remarkable regenerative capacity. Field horsetail thrives in acidic, poorly drained sandy or gravelly soils and full sun. Although it is considered a wetland plant, it can also be found in drier areas.

Control Methods Cultural Control: First, improve the drainage, then raise the pH by applying dolomite lime at the rate recommended on the package. Wait at least two weeks before increasing your soil’s fertility by adding fertilizer, since lime and fertilizer tend to cancel each other out if applied together. Because horsetail does not respond to nitrogen fertilization and wants sunlight, its growth can be suppressed through the use of a fertility program and competitive cover crops. Other control options that have met with some success include use of inorganic mulches and weed barrier fabrics. Improving drainage in the area can also be helpful.

Mechanical/Physical Control: The tenacious root system of field horsetail makes it very difficult to control, particularly when using mechanical methods that can actually worsen the problem by spreading rhizomatous pieces that can regenerate. The fertile horsetail stems should be cut or burned before they form spores in order to reduce spread potential. Repetitive tillage or mowing over at least a 2-year period may be effective if timed to eliminate regrowth before the plants are able to replenish their energy reserves—shortly after emergence and before reaching 8 inches in height. Shallow tillage is not recommended. As is the case with most invasive plants, the most effective management approach will involve a combination of methods, such as applying herbicides after mowing.

Chemical Control: Few herbicides have any effect on field horsetail and their use depends on the situation in which it grows. In non-food areas, diclobenil (Casaron®) is labeled for field horsetail use. Multiple chemical treatments may be necessary but cannot be applied by a homeowner, you must be a licensed applicator.

Reference: http://extension.wsu.edu/whitman/wp-content/uploads/sites/28/2013/11/Horsetail2010_000.pdf?x11869

Your question about hydrangeas, yes they grow very well here. There are several colors, varieties and sizes. I recommend visiting a nursery in your location.