Maintenance

Controlling weeds is the biggest priority the first three years after an area has been planted with native seed. The native seed you plant will only grow a few inches the first year; weeds will grow much thicker and taller than the natives and can shade out the native seedlings. Diligent weeding the first three years will greatly reduce the amount of weeds you have on your native establishment. Once the native species mature, they should be able to crowd out the weeds on their own.

First Year

Mowing is the primary tool for controlling weeds the first year. Keep the vegetation mowed to a height of 4-6 inches and mow when the vegetation reaches 10-12 inches. This may require mowing about once a month depending on the amount of rainfall. Mowing keeps the weeds from becoming too tall and shading out the natives and it also prohibits the weeds from setting and dropping new seed into the soil. Stop mowing at the end of the growing season (September). Some additional weed growth at this time of year will help protect the seedlings during their first winter.

Hand pulling weeds generally is not recommended the first year because of the risk of pulling out the seedlings and bringing up new weed seeds to sprout. In general, spraying herbicide on a native planting is discouraged. You can, however, consider spot treating with herbicide the aggressive weeds, such as Canada Thistle or Spotted Knapweed that can become very invasive if allowed to persist. Spot spraying needs to be done very carefully by a person who has experience in the use of herbicides as well as in the identification of all of the plant species present. The proper herbicides and rates depend upon the target species as well as the season of the year.

For some plant species hand-wicking with herbicide may be desirable. Mix up a strong solution of the appropriate herbicide and put the solution in a spray bottle or other non-spill container. Wear rubber gloves and put an absorbent cotton glove over the rubber glove on one hand, carefully saturate the cotton glove, and apply the herbicide to the leaves and stems of the plant. Try not to touch any desirable seedlings. It is imperative to closely monitor the gloves to make sure no tears in the rubber gloves allow the herbicide to contact the skin of the applicator.

Second Year

Weeds will often dominate in the second year as well, so continuing to mow is vital. You should mow the vegetation during the second year to a height of about 8 inches. Mow when vegetation reaches 12-18 inches. Some of the natives may be up and blooming but it is worth sacrificing the flowers at this stage to achieve a more successful native planting in the long term. The natives will not be killed by this mowing.

Hand pulling and spot treatments of herbicide may be needed and beneficial during the second year. Common competitive weeds in the second year include Spotted Knapweed, Canada Thistle, Burdock, Wild Parsnip, Sweet Clover, and Queen Anne’s Lace. Mowing them when they are in full bloom will set them back and prevent them from setting and dropping seeds.

Burning the second year is not usually recommended; normally there is not enough fuel to sustain a fire and some natives are too immature to be damaged by burning.

Third Year and Beyond

Burning the third year, and on a regular basis in future years, is the most important tool to manage the weeds on your property. If burning doesn’t occur, a thatch layer can accumulate on the ground and cause poor growth or cause plants to die out completely. Prescribed burning kills or at least reduces weed growth and also stimulates new growth of the native species.

Spring burns in March or April are most effective for most plantings. Only experienced, trained crews should perform the prescribed burn. Be sure to check with your local fire regulations and obtain the appropriate permits. A wide path (10-15 feet) around the perimeter of the native planting, called a burn lane, acts as a firebreak and should be kept mowed throughout the growing season.

After the third year, burning should take place every one to three years. Consider a burn rotation in which ½ or 1/3 of the area is burned one year and another section burned the next year. This will protect over-wintering butterflies, moths, as well as early nesting birds.

If burning is not allowed in your area or it is not an option for other reasons, mowing and removing the clippings, although not as effective, can be a good substitute. Mow down close to the surface (4 inches) in early spring (February through April) and use a rake to remove the clippings. Note that some ground-nesting grassland birds nest as early as April, so the earlier the better. If removal of clippings is not possible, raise mowing height to 8 inches or so.

Spot treating with herbicide may still be needed if weeds persist, however, once your natives are established, they should require minimum maintenance.