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NativeGrass Restoration Project

When the Spanish came to California, they brought with them not only cattle but also many Mediterranean grasses that were native to Spain. These annual grasses use water very intensively and competed strongly with the perennial bunch grasses native to this area. While the native grasses have not disappeared completely, they are far less common than they once were. The rest of the plant community that accompanies bunch grass -- yarrow with fern like leaves, blue-eyed grass with angular shoots and dark blue flowers, yellow buttercups and soapweed -- has also become less common. The Walnut Creek Open Space Foundation's native grass restoration project is attempting to learn how we can make native grass and its associated plant community more prevalent in our open space.

Promoting the Recovery of Native Grass

Over a period of several years we have planted several plots of native grass -- primarily purple needlegrass ( Nasella pulchra). We gather seed from native grass patches within Shell Ridge and plant them in flats. After the first winter rains, we transfer them to plots in the open space. Our most successful plot is near the Marshall Drive entrance to Shell Ridge at the site of the helicopter crash a few years ago. About 40 grass plants have survived.

In 1997, we acquired a sickle-bar mower which is well suited to mow tall grass and weeds in uneven ground. We mow stands of mixed annual and native grass to suppress the normal production of seed by the annual grasses. We plan to use this technique around the edges of native grass stands to allow the stands to expand.

Controlling Exotic Pest Plants

Our open space has been invaded by a number of non-native plants that crowd out grasses and other plants and make the area less usable. Black mustard forms thick stands that shade out most other plants. Several kinds of thistles also crowd out other plants. In addition, their stiff thorns make the area less pleasant for people, horses, dogs and cattle to use. Over time the pest plants reduce the variety of plant and animal life and make the open space less interesting and inviting.

The Foundation is using our sickle-bar mower and our rotary mower to cut down patches of mustard and thistles. Our goal is to first prevent the further spread of these pest plants and then to reclaim part of the area they now cover. While the area covered by pest plants in the open space is too large for us to mow completely, we can target the edges of some pest plant patches and keep them from growing.

Email us at contact@wcosf.org for more information or to volunteer.   Or click here to contact us by mail or phone.