Fall Renovation of Pacific Northwest Horse Pastures
/By Alayne Blickle, Horses for Clean Water
Healthy pastures are an important key to a healthy ecosystem. Grass plants act as biofiltration to keep nutrients and sediments from mud, manure, and urine from running off into surface water and causing pollution issues. Plants slow the flow of water, allowing it to soak into the soil where plant roots can utilize moisture and nutrients, instead of allowing them to wash into storm water.
Early fall is an ideal time to renovate a pasture and get it established. Warm fall soils encourage root growth which will continue until the ground freezes. In areas with mild winters, roots may continue to grow all winter. Once early spring rolls around, roots begin new growth or continue growing but at a faster rate while also beginning top growth. By contrast, a grass seed planted in spring will get a much slower start due to the cooler soil temperatures.
When next summer rolls around, fall-planted grass is far better equipped to deal with heat and drought because of its well-established root system. Other good reasons to plant in the fall include dependable rainfall, cooler weather (which most grasses prefer), fewer pest and disease problems, and less competition from weeds. Soils also tend to be drier in the fall than they are in the spring, making them much easier to prepare for planting.
Fall planting should be done roughly six weeks before the first hard frost which, in the Pacific Northwest, is probably mid-September through mid-October.
Here is the 10-step process:
1. First, a good rule of thumb is to never renovate more than 20% of your property at one time. The reduced grazing area puts more pressure on the rest of your pastures.
2. Kill existing vegetation about four to six weeks before seeding. Mature plants with roots and leaves will always out-compete seedlings for nutrients, so help the seeds by getting rid of competition. Kill undesirable plants either chemically (with herbicides) or mechanically (by pulling weeds or by thoroughly discing.) If discing, allow a few weeks afterwards for green vegetation to decompose.
One more option is to use a no-till drill for seeding. No-till is an agricultural technique for growing crops or pasture without disturbing the soil, thereby decreasing erosion, and improving soil health.
3. Evaluate the current soil status with a soil test. Snohomish Conservation District can assist with information on how to get a soil sample and where to have it analyzed, as well as with information on soil nutrient levels and fertilizer and lime recommendations specific to your situation.
If the soil test results indicate your pastures need liming, fall is an excellent time to do this. Fall applications allow lime to neutralize soil acidity over the winter and helps grass plants to be more competitive next spring. Lime comes in a powder or pelletized form. Useful tools for spreading lime include a drop seed spreader (for pelletized) or lime spreader (for powder). Spread lime at the recommended rate about two weeks before seeding.
Spreading compost
Credit Alayne Blickle, Horses for Clean Water
If you have compost available, use it! Besides adding microbial health to soils, compost adds micro and macronutrients over a sustained period. It also helps hold moisture, which is of critical importance with climate change and pasture management.
4. Seedbed preparation includes breaking up compacted layers. Compaction restricts roots and water penetration. Useful tools for this task include a ripper or aerator as well as a disc. A harrow will smooth and level the top layer. Your goal should be to produce a firm, level seedbed with just enough loose surface soil for shallow seed placement and good seed-to-soil contact.
5. Select seed types for your pasture. Pasture seed mixes are usually sold in multiple-species mixtures. While at least one species in a multiple-species mix will always grow, it is better (and more cost-effective) to choose the species you want for the conditions you have.
Choose a pasture mix specific for Pacific Northwest horse pastures. Some mixes contain seed varieties that do well in other parts of the country. For example: Kentucky Bluegrass is susceptible to mildew and rust in the PNW and will die out in a few years. Fine fescue has a low palatability for horses and high susceptibility for endophytes. Never use lawn or “turf” seed for horse pastures as these are not designed for grazing herbivores and can be detrimental to animal health or cause reproductive problems if they are high in endophytes. Instead, choose a horse pasture mix designed specifically for the PNW region. A general pasture mix of orchard grass, perennial ryegrass, and tall fescue (endophyte free) works well; timothy grass usually dies out quickly as it gets out-competed by other grasses or doesn’t survive grazing. Contact Snohomish Conservation District for advice specific to your conditions.
6. Apply seeds at a rate of 30 to 50 pounds per acre (this is called the seeding rate.) See the next step for seeding tool suggestions.
7. Seeding depth is critical. Grass and legume seeds are extremely small and if buried too deep in the soil they will run out of energy before the germinating plant reaches the surface. Never seed deeper than ¼ inch. It’s better to seed too shallow than too deep. Useful seeding tools include a hand spreader, a push spreader, or a drop seed spreader.
8. A light harrowing after seeding will help achieve good seed-to-soil contact. To reiterate: a firm seedbed is essential. If the soil is too fluffy it will dry out quickly and the small seedlings will die. You can tell you have a firm seedbed if you can walk over the prepared seedbed and leave footprints no deeper than 1/4 inch.
9. Weed control before and after seeding is critical to the success of the new planting. Repeated tilling or mowing of the area throughout the growing season prior to seeding will reduce (but not necessarily eliminate) weeds. The best method for weed control after seedling emergence is mowing—young plants are highly susceptible to herbicide damage so now is not the time for applying herbicides. Mowing the growing grasses at about six to eight inches will stunt or kill most weedy plants.
10. When to begin grazing? A renovated pasture will take almost a year before it’s established. A fall-established pasture may be able to be grazed late in the following summer, but only if it passes the “pull test.” This is a test to determine whether your grass plants have strong enough roots to be grazed. Get on your hands and knees and grab a single plant at its base. Give it a sharp tug. If you can pull the plant out of the soil, then so can your horses and your pasture is not yet ready to graze. Even after a new seeding does pass the pull test, only graze lightly for the next 90 days and never below four inches to be sure your plants develop a strong, healthy root system.
Once your newly established pasture has passed the pull test and you are ready to turn horses out on it, be sure to follow all the guidelines of good pasture management: utilize your confinement area to avoid grazing any area below four inches. Don’t turn horses out on soggy soils or dormant winter pastures to avoid soil compaction. Consider cross fencing and dividing up your pastures into several smaller areas to utilize a rotational grazing program to increase forage production and keep pastures from becoming overgrazed. Consult Snohomish Conservation District for more help with part of this process. Happy grazing!
This project has been funded wholly or in part by the United States Environmental Protection Agency under assistance agreement PC-01J18001 to the Washington State Department of Health. The contents of this document do not necessarily reflect the views and policies of the Environmental Protection Agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.
