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https://www.gardeningknowhow.com/garden-how-to/gardening-by-zone/zone-5/ornamental-grass-in-zone-5.htm

You should be able to grow Blue Oat Grass in your region. You may need to add additional watering care during hot spells.

https://www.gardeningknowhow.com/planting-zones/california-planting-zones.htm
https://www.gardeningknowhow.com/ornamental/foliage/blue-oat-grass/ornamental-oat-grass.htm

The root system in clumping and goes approx 12 to 18 inches deep.
Most grasses spread out, though they generally stay in a clump.

Refer to the specific grass your planting and check the size at maturity. This information should be on the tag or you can search this easily, right on our web site!

Grasses are perfect for rock gardens! I would give 12 inches from a large rock formation.

This may be a bit tricky to solve. If there is no way to till and remove, you may have to kill the area, and re-seed with fresh grass, or whatever else you may want to put down.

nspect your switchgrass plants periodically during watering time to look for troubled areas. Remove any broken, dying or otherwise damaged blades or stalks throughout the growing season as you spy them. Place the cut at the base of the blade or stalk just above the crown of the clump and pull the cutting clean from the canopy.

Shear down the dead top foliage in winter after the first hard frost or leave the drying grass in pace to provide visual interest in the garden during winter. Cut back all of the dead grass in the early spring down to the crown to make way for fresh green growth. Discard or compost the cuttings.

Prune lightly to tidy the switchgrass that successfully overwinters in warmer climates. Remove only the damaged or unattractive individual blades by cutting them off at the crown and pulling them out. Cut back any blades that are lying on the ground from weather damage or have been trampled, in order to preserve the natural fountain form.

Now or early spring are the best times. Hot, sunny weather is the enemy of transplants. In fall even after the grass turns tan, the roots still work to get established until the ground freezes. Water as needed until then. Leave the grass intact over winter the first year to add a bit of extra protection. Several types of feather reed grass are available. Here is a link to articles that discuss different hybrids. https://www.gardeningknowhow.com/ornamental/foliage/feather-reed-grass