Why purple fountain grass, Pennisetum setaceum Rubrum, is a better landscaping plant than P. alopecuroides. Pruning purple-leaved fountain grass. Growing red fountain grass in California.
First, let me state that purple and red fountain grass are the same plant. They are both common names for Pennisetum setaceum 'Rubrum'.
In my opinion, this is the most attractive and most useful of the fountain grasses. With its red-brown leaves and burgundy flower plumes, P. setaceum 'Rubrum' is more colorful than the more subdued Pennisetum alopecuroides . At 4-5 feet tall, it is also larger.
But the reason I so greatly prefer it to its green-leaved cousin, is because it does not set seed.
Let me rephrase that. It seldom sets seed.
I have several mature clumps of perennial red fountain grass around the yard. Every other year or so, I find a seedling of it in the garden. The occasional volunteer is cute. When they're everywhere, that's not cute.
To get the plant off to a fast start, plant it in well composted soil. Full sun is the preferred exposure. If you live north of USDA zone 9, a southern exposure in a warm microclimate may be warm enough to pull the clumps through all but your coldest winters.
Water the clump regularly its first year in the ground. If you are growing red fountain grass in a container, water it often enough to keep the soil in the pot from drying out.
Established clumps are wonderfully drought tolerant. Of course, they look nicer with fairly regular water.
Fountain grass is not a particularly heavy feeder. You can feed it once per season with whatever you like. I just top dress the soil around my clumps with compost in the spring after I cut them back. They may accidentally get a little food when I feed the plants around them.
Buy Plants Below:
Purple fountain grass used in a landscape.
Using a power shear will make pruning purple fountain grass a quick and easy task. Cut the clumps straight across the top.
Leave 12 inches of growth on each clump.The safest time to do this is soon after you notice new growth in the spring. If you prune them too early, a late freeze may kill the clump.
The brown leaves not only add winter interest to the landscape, they protect the roots from frost. Red fountain grass is reliably perennial in zones 9-11.
After you cut them back, examine the base of the clump. After several years of growth, the clump will tend to die out in the center. When this happens, it's time to dig it up and divide it.
The easiest way is to cut the clump in half, discard the dead center and replant each half. You could divide it into quarters, but I find that larger clumps reestablish more quickly. This is a good time to replenish the soil with fresh compost. Keep the new divisions moist for the rest of the growing season.
The Bronze Leaves of Red Fountain Grass in December.
Pennisetum setaceum 'Rubrum' is a plant that thrives in wet or dry soil. I'm growing it in central Florida which has rainy summers and dry winters. This is precisely opposite of the California climate.
But Florida weather is freakish in that during our typically rainy summers we always have several weeks of drought. Couple this with 100+ degree temps and our landscapes really suffer.
This doesn't seem to bother the purple leaved fountain grass which lives on natural rainfall alone in my yard. I have only lost one clump in the 10 years I've been growing it. As long as you are in a warm area of California, it will be perennial. I happen to know that purple fountain grass grows beautifully in Los Angeles which is in zone 10.