Native Seed Mixes

by Bruce Berlin

Used effectively, native seeds and plants have been playing important roles in our landscapes. In recent years, more information and applications exist for the native plant materials. Native seed mixes and plants are a tool that give good results, provided they are used correctly.

Native plants have been getting a lot more attention in recent years. Supported by Federal directives, State and local ordinances, and with assistance from regional planners, planning commissions, and other municipalities - many projects are required to attempt to use native vegetation where practical. Nationwide, projects are being designed, built, and installed with native plants and seed mixes as an integral part of the project. The landscape and erosion control industry has developed several subcategories such as: "native plant establishment", "habitat establishment", and "restoration, and/or revegetation services" to keep-up with this viable category of native plant establishment.

The benefits of using native plants instead of more "traditional" plant material are many:

  • Promote Biodiversity: Contributes to the ecological balance of flora and flauna that have evolved in your geographic area. Natives perpetuate the relationships that exist between our native plants, the soils, and the many organisms that depend upon them for survival.
  • Save Time, Money, and Energy: When used wisely, native plants generally require less maintenance. Native plants are less expensive in the end and save energy because they do not have to be mowed or manicured as frequently as "conventional" lawn and plantings.
  • Conserve Natural Resources: Because they are adapted to our soils, temperatures and rainfall patterns, native plants typically require less irrigation and fertilization than traditional plantings. This does not mean that native plants and seedlings don't require any water to get established; rather it means over the years, the native flora will not have the demands of a non-native planting.
  • Attract Wildlife: Native plants are the best choice for attracting and nourishing our native wildlife. Birds, mammals, butterflies and other wildlife enjoy the many characteristics that native plants provide. The National Wildlife Federation, The Audubon Society, and other animal support groups are strong advocates in the use of native plants.
  • Education/Awareness: The community as a whole learns that native plants, if used and managed correctly, can provide beauty and variety, as well as practical and functional landscapes. An appreciation is gained for the plants and animals that people see while hiking, camping, and traveling through an open natural area.

In 1994, President Clinton recognized the natural landscaping movement by issuing an Executive Memorandum that not only recommended native landscapes at all federal facilities and on federally funded projects, but presented guidelines for doing so. Many highway projects, under the directive of the Federal Highway Administration, require that native plants and wildflowers be utilized in roadside plantings.

The Native plant industry has grown tremendously in the past 10 years, and with it, opportunities to find locally produced native plant materials. More species are available in nurseries and from seed suppliers. Many databases and cultural practices are available. Symposiums and conferences in native plant establishment help distribute practical information about the use and limitations of native plants. Landscape Architects have had to learn to use their resources more to develop plant palettes that accomplish the desired results. Native plant demonstration gardens, native plant societies, and the computer resources all provide a wealth of information on individual native plant species and sources to obtain the plant materials.

Native Seeds or the 'introduced species"?

As far as native seed mixes go, there are many considerations. The important thing to determine is whether native seeds are appropriate for the specific site and project. If the project lies in an area that interfaces with an "untouched" native open space, then perhaps trying to match the seed mix with the surrounding native area is a good idea. On the other hand, if there are temporary housing pads that are going to be re-graded and traditionally landscaped in a few months when the weather improves, then why use slower establishing, native seeds? You cannot generalize and come-up with a "boiler-plate" native seed mix. Each particular project will have certain criteria that will dictate whether you should use strictly native plants, non-natives, or a combination of the two. I would encourage you to contact a reputable seed supplier in your area to help you formulate a mix that accomplishes what you are seeking to accomplish.

How Do I Choose My Native Seed Mix?

Certainly, there are many, many choices to use when formulating a seed mix. I would suggest using a native seed mix if the environmental conditions and the nature of the project would favor that over an introduced species. However, in many instances, introduced species or proven performers, not necessarily native to your area, are perfectly acceptable. It helps to confer with the local professionals, like the Resource Conservation Districts, the Biologists, or the Engineers in your given area to evaluate what has been working well in your region.

Native seed choices and availability are now better than ever. Dependable seed suppliers will often use local seed collections and very complex seed cleaning and conditioning equipment. In fact, it is now possible to ask seed companies origin of the seeds, and in some cases "source identified" seed is obtainable. Thus, it is now possible to develop a plant or seed mix palette that fits the local flora, soil types, and ecology, and then specify that the seeds be from a designated region. Theoretically, these plants will be better acclimated to your site and will perform better. I suggest you talk over your project and check local seed availability with your local seed supplier. Ask them where their seeds originated. A good seed company will ask you a series of questions about your site and help you formulate an appropriate seed mix.

Some of the basic guidelines you should consider when using natives:

  • Choose the Right Plant Material For Your Specific Area: Look around. See what has been used on successful projects in your area. Are there some neighboring sites that have used natives in their seed mixes? Are there some undisturbed areas close by that could help you choose your plants that stand a good chance of surviving? Check with a native plant society or nursery association for their suggestions.
  • Soil Assessment/Site Assessment: Too often, we are placing seed mixes in a very stressful environment. Often we see projects seeded on overly compacted slopes, without any organic matter or beneficial microorganisms, and/or a huge weed bank. Do your best to take some soil samples, make some effort to improve the "plant ability" of the soil, and choose plants that are acclimated to your soil conditions. Some seeds prefer dry, sandy soils, and others will tolerate heavier, clay soils. What other factors are on-site? Is there a huge stand of Eucalyptus or Pines that shade the seeded area all day long? Are there neighboring fields of weeds that will blow into your planting area? Is the planting area subject to traffic and needs some type of barrier to keep people off it?
  • Match Plants, Preferred Habitats, and Overall Objectives: This is critical. Some seeds and plants prefer specific habitats. It is not wise to take a coastal plant and expect to get results planting it in the desert. Study plant databases and native plant books. Good seed companies publish an informative description of the native seeds needs in their catalogs.
    The overall objective is equally important. If the intent is to have a permanent, no maintenance mixture of shrubs and grasses, plan accordingly. In this scenario, it is not wise to load up your seed mix with annual wildflowers and short-lived plant material, which will have to be re-seeded or maintained annually.
  • Include a "Balance" of Plant Material: It may be wise to use a combination of annuals and perennials, depending on the objective of the project. The annuals, in general, will germinate quicker and give you results in the first six months, while the slower-establishing perennials are establishing themselves. If the seed mix is overloaded with annuals, you may out-compete the desirable perennial species. Good seed suppliers will give you seed count information and tell you typical purity and germination percentages.
  • Control The Weeds/ Perform Maintenance: Eliminate weeds before you plant a single seed. It is advised to perform a "grow and kill" cycle, to encourage weeds to grow, then eliminate them before putting your good seeds out. This can be accomplished with water and fertilizer, followed by a glyphosate application when weeds germinate. Do it twice if time allows.
    If using an irrigation system to facilitate germination and establishment, make it a point to check the effective coverage of the system monthly. In addition, check the irrigation cycles. Make sure there is not too much or not enough water being delivered to the seeds and seedlings. Faulty irrigation coverage or practices are the number one reason why seed projects fail.
  • Plant Under Favorable Conditions/Timing: If possible, plant at a time when your seeds stand a good chance of survival. In California, we normally suggest Fall planting. In other areas, plant after the danger of frost has expired. Try to minimize the risk associated with your planting. Use a temporary, aboveground irrigation system as a form of insurance if feasible. On non-irrigated sites, plant at the onset of rainy season. Do not plant your seeds too deep. In most cases, lightly scratching your seeds into the soil will suffice. L&W

For more information, contact:
Bruce Berlin, Horticulturist for the past 9 years at
S&S SEEDS, PO Box 1275, 1275 Carpinteria, CA 93014-1275
(805)684-0436, Fax: (805)684-2798.

©2000, 1999, 1998 Land and Water, Inc.
Monday, November 13, 2000 -