California perennial bunch grasses provide many benefits, including reduced water usage, excellent erosion control, wildlife habitat, as well as aesthetic beauty.  It is worth the effort to follow a few simple techniques to insure successful establishment and provide years of benefits.

1. Seed Selection: It is very important to choose healthy, fully-formed seed that is adapted to your site and climate. The seed should be tested for germination, purity, and weed seed content.  Criteria that must be assessed include site elevation, aspect to the sun, seasonal rainfall and temperature, and the potential for seasonal flooding and the ability to withstand it.

2. Site Preparation: The greatest challenge to native seed establishment is weed competition. If possible it is best to begin weed control 6 months to a year in advance.  This should consist of trying to sprout and then eliminate the weed seed bank in the top few inches of soil. This can be done by physical means such as disking, harrowing, tilling, burning, or by herbicide application.  These cultural practices can be repeated 2 or 3 times as subsequent flushes of weeds emerge.  Irrigation can speed up the process by decreasing the time between applications and allowing out of season treatments.  It is best to use methods that cause less disturbance, as weed seed is scattered throughout the soil profile and will be brought to the surface with disking or tilling. Burning, if possible, is an excellent method, as is the use of Round-up Herbicide at a 1.5 % rate.  It is best to plant immediately following the weed control treatment.  Weed seeds left in the soil will germinate and emerge before the natives.

3. Planting: The best time to plant seed depends on whether irrigation is available or not.  Without irrigation the ideal time is from mid-October to mid-January. With irrigation the window for seeding can be extended to before or after these dates.  Seed can be incorporated into the ground by broadcast application, drill seeding, or hydro-seeding.  The seed bed should be firm and the seed should be planted to a depth that will stay in contact with soil moisture between rain events. A ring roller is a good tool to firm the soil and ensure good soil-seed contact. Again, it is best to minimize soil disturbance at this time.  Since native seed can take 2 to 4 weeks to germinate during the cool season, it is possible to spray Round-up on any weed seed that emerges before the native seed does. It is best to use minimal fertilizer until the field matures, as this seems to favor weedy growth.

4. First-Year Weed Control: After the grasses have grown beyond the 3-leaf stage, it is possible to spray a broad-leaf herbicide to eliminate any weeds that germinate after pre-plant preparation.  Herbicides like Trimec or Triplet, with active ingredients including 2-4D, MCPA, and dicamba, can be applied at low label rates with good success. If necessary a follow up application 4 to 6 weeks later should eliminate most broadleaf weeds. Annual grasses are more difficult to eliminate, but can be controlled by mowing to eliminate seed head formation, until the perennials become thick enough to cover the bare soil.  Poast, a grass selective herbicide, can be used on the fine Fescues, such as Festuca rubra, to eliminate weedy grasses.

5. Second-Year Weed Control: After the first rains, between October and December, a pre-emergent herbicide, such as Prowl or Pre-M which contain pendimethalin, or Barricade 65 WG, which contain prodiamine, can be applied to control emerging cool-season weeds.  After emergence a broadleaf application can be applied, again at low rates.  Between April and June, warm season weeds may be activated.  These can be controlled by another pre-emergent application, broad-leaf application, burning or mowing.

6. Third-Year Management: By the third year the grasses should be competitive and self-sustaining.  Some management may be necessary to keep and maintain the health of the stand. The tools used thus far, herbicides, burning, mowing or grazing, can be applied as necessary, as a response to field growth and success of weed control. 

Native perennial grasses provide many benefits.  It is worth the extra effort at the beginning to ensure successful establishment.  After they are established they can be relied upon to provide years of care free sustainability, benefiting the environment, and providing a cornerstone for the successional rehabilitation of the natural ecological order.

Notes: This planting guide was provided courtesy of Rana Creek Nursery.

Although herbicides/pesticides are mentioned as tools in the above description, The Soquel Creek Water District recognizes and encourages the use of “green” techniques when possible.