Help for the Home Gardener from the Help Desk of the
UC Master Gardener Program of Contra Costa County
Client's Request: I have a very large Purple Fountain Grass plant. I'd like to thin out the plant and cut back the outer “stalks” that keep falling down, generally to “tidy it up”. How large can it grow and what care should I be giving it? Also, I have some nearby blue fescue with reddish brown stalks that I think should be “blue”. Do you think the Purple Fountain Grass might be causing this? Finally, as I've previously mentioned, I'm thinking about thinning and/or transplanting the Fountain Grass, when and how should I do that?
Purple Fountain Grass (Pennisetum, setaceum) is a perennial plant in Sunset Zones 8-24 (USDA zones 9 or higher) but in colder areas with heavy frost, it is usually grown as an annual. It is native to South Africa, southwestern Asia, and the Arabian peninsula. It is classified as a warm season grass, which is important to know when wanting to prune or divide the plant. It also tends to die back in the winter. It grows best in full sun, in well-draining soil, and is moderately drought tolerant. It can grow in poor soil with little care but will flourish with a little more water and fertilization. As you are aware, it can grow to about 5 feet tall and wide. It is very showy especially in the fall and offers a lovely contrast when planted with other plantings.
Answering your first question on how to thin out the plant and what to do with the falling outer “stalks” (flowers) --the best time to prune fountain grass is late winter or early spring--but be sure to prune before the grass begins to re-grow. Also avoid pruning in the fall before the plant has had time to go dormant.
It is also recommended that you wear gloves and long sleeves as grasses can be sharp and cause itching. Use sharp pruners or hedge clippers. You may need to re-sharpen them as grasses dull cutting blades. Grab the plant and tie a string or tape around it and cut straight across the plant 4-6 inches from the base. Using your hands or a tool, comb through the remaining plant to remove dead grass. If you wish to thin the plant, make small cuttings inside of the plant in several areas. The remaining grass stalks will "disappear" when the plant re-grows and will provide some support to the flowers and blades. This is an arching type of grass so some flowers will fall around the periphery of the plant and you can trim these away but again leave 4-6 inches of the blades. Here is a link to a UC article about pruning ornamental grasses: http://sonomamg.ucanr.edu/2010_Feature_Articles/Pruning_Ornamental_Grasses/.
Your second question was about the blue fescue with reddish brown stalks and whether or not the fountain grass could be causing this to happen. I could find no information in my research about fountain grass causing this problem. Browning of grass may be due to excessive watering or fertilization or the plant being root bound or excessive sunburn. It may also be the result of the fountain grass shading the blue fescue. Pruning away the brown grass is suggested as well as pruning the fountain grass so it is not shading the fescue. If the discoloration is due to a rust problem, here is an article that tells you how to manage this disease: http://ipm.ucanr.edu/PMG/r785101611.html.
Your third question about transplanting a fountain grass clump and thinning out the plant: you will want to dig up the root ball. You can best transplant and/or divide up the clump in the fall before dormancy or in the spring when the plant is beginning to re-grow. Here is a link which will give you more information: http://sacmg.ucanr.edu/files/117290.pdf.
I hope I have answered your questions and the links are helpful to you. Let us know if you have any further questions and we hope you are successful with transplanting these beautiful grasses.
Help Desk of the UC Master Gardener Program of Contra Costa County (EKP)
Note: The UC Master Gardeners Program of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925)646-6586, email: firstname.lastname@example.org, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/CCMGBlog/)./span>
1) rototill what's left of the current lawn and remove as many grass clods and rhizomes as I can gather up in this process
3) cover with newspaper
4) cover that with more soil (excavated from a large bed elsewhere in the yard; clean and much better structure) and compost
5) poke holes into the paper to plant some F. rubra plugs I bought (prematurely) and overseed with F. rubra seed.
6) cover with mulch.
- the soil is so compacted that it NEEDS some cultivation, despite the risk of chopping up rhizomes (besides existing grass is not very healthy); I'm loathe to put off cultivation till spring because if we get El Nino type rain that could just exacerbate the clay soil structure (ie, further compaction)
- I can plant the grass plugs now through the newspaper
- F. rubra seed can take advantage of early rains now and newspaper will hopefully rot by spring so new grass seedlings can tap the underlying soil then when days lengthen, temps rise and growth rate increases
- If El Niño rains come, this approach will prevent excessive pooling and muddy bog conditions.
The other option is rototilling and sheet mulching now and composting and seeding in March or so.
I'd appreciate your thoughts and comments. Thanks very much for your time.
Help Desk Response: Thank you for contacting the Master Gardener Help Desk concerning your lawn conversion from Bermudagrass to red fescue.
Bermudagrass can be pretty tough to eliminate. The best methods include the following (summarized from very detailed University of California information located at http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7453.html):
1. Herbicide such as Roundup™, during spring and summer. Herbicide will only be effective if applied when the Bermudagrass is growing vigorously, meaning it should be applied during spring and summer. Stolons may not be completely killed by herbicide, so cultivation may also be required, as further described below.
2. Withholding water during summer. This tactic is usually combined with cultivation, also further described below.
3. Shading. Sheet mulch with overlapping cardboard sheets, covering the cardboard with at least 3 inches of mulch. Mulch alone will not be effective. More information on sheet mulching, including a "how to" slide show, can be found here http://www.bayfriendlycoalition.org/LYL.shtml
Based on the above, you can see that summer is the best time to effectively eradicate Bermudagrass by using a combination of methods. Herbicides will not be effective during late fall and winter because the Bermudagrass will not be growing vigorously. If you decide to cultivate and hand remove rhizomes and stolons, followed by sheet mulching, that is probably your best bet this time of year. However, we would recommend that you wait to plant the fescue plugs until you are confident the bermudagrass has been killed. If you do not, there is the potential that the bermudagrass will grow through the planting holes.
It is true that fall is the best time to seed Festuca rubra to take advantage of the rains. Festuca rubra is a low water use plant according to WUCOLS http://ucanr.edu/sites/WUCOLS/Plant_Search/. However, even plants that are classified as "low water use" require supplemental water for the first year or two to get their root systems established and are drought tolerant only thereafter. You may want to keep this in mind when deciding when, and how much, to plant, in case landscape watering restrictions continue next year.
General advice from the University of California about establishing and maintaining lawns can be found here, including information on pre-plant fertilizer http://www.ipm.ucdavis.edu/TOOLS/TURF/ We do also recommend that you have your soil tested to determine if certain nutrients are lacking so that you can fertilize and amend appropriately. A list of soil testing laboratories can be found at http://ccmg.ucanr.edu/files/51308.pdf. The soil testing labs' websites have instructions on how to collect samples and submit them for analysis, but you should contact the lab first to get their specific requirements for you situation. A basic soil test should include the major nutrients of nitrogen, phosphorus and potassium (N, P, K) as well as pH and organic matter. pH will tell you whether your soil is neutral, acidic or alkaline - this is important because pH can impact nutrient availability. Ideally you will want the soil pH to be between 5.5 to 7.5. 5% organic matter is considered ideal; our clay soils usually have much lower than ideal levels, but can usually be improved with the addition of compost.
Good luck with your ambitious project. I hope that this information is helpful. Please do not hesitate to contact us again if you have any further questions.
Editor's Addendum: A relatively new development on the California turf scene is that at least one sod grower, and probably others as well, are now providing ready-to-install sod that consists primarily of native grasses and also touting significant reduction in water use. Your circumstances might warrant consideration of such sod. Details on feasibility and costs should be available at most retail nurseries or online.
Help Desk of the UC Master Gardeners of Contra Costa County (JL)
Note: The UC Master Gardeners of Contra Costa's Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: email@example.com, or on the web at http://ccmg.ucanr.edu/Ask_Us/ MGCC Blogs can be found at http://ccmg.ucanr.edu/HortCoCo/ You can also subscribe to the Blog (http://ucanr.edu/blogs/blogcore/blogroll.cfm)./span>/span>/div>/span>
Help for the Gardener from the Contra Costa Master Gardener Help Desk
Client's Request: I am looking for advice on a drought tolerant grass variety or mix for my front yard. We are located in San Ramon, and the area receives full sun. We have taken out our existing lawn! We will have edibles, water permeable surfaces, paths and a small amount of grass (or other suitable ground cover), about 200 ft2. This will be mostly ornamental, although one area (next to the driveway) will likely receive some foot traffic. I identified UC Davis Buffalo grass as a possibility, but we are open to anything that makes sense. Most important are low water requirement and low maintenance, ability to tolerate some foot traffic, open to a longer ‘shaggy' growth habit, although the ability to mow to a shorter length would be nice. Full sun environment. Soil is good I think, some clay but not too heavy, drains well.
CCMG Help Desk Response: Congratulations on taking the first step towards a water-wise garden by removing your lawn. It's important that we all learn how to use water more efficiently as demand rises and drought conditions continue. You would like to retain a small lawn which will receive foot traffic next to the driveway and would like advice on grass selection.
Before evaluating lawn alternatives, it is important to understand the differences between the two categories of grasses. Grasses are considered warm-season or cool-season, depending on when they grow best. In California warm-season grasses (e.g Bermuda, St. Augustine, buffalo) generally do best in southern California while cool-season grasses (e.g. blue, rye, fescue, bent) do best north of the Bay Area. In between is a transition zone, where both cool-season and warm-season grasses will grow but the climate is not optimum for either. Warm-season grasses tend to turn brown and go dormant during the winter in areas where there is frost, such as San Ramon. And cool season grasses require extra water to endure our hot dry summers.
Below are several options for lower water use grasses which can tolerate foot traffic. However, none of the grasses listed below currently qualify for your Water District's (EBMUD) lawn conversion rebates, nor does synthetic turf. In order to qualify for a lawn conversion rebate, EBMUD requires that the lawn be replaced with low or very low water-use plants, or permeable lawn alternatives such as decomposed granite or mulch.
Native Bentgrass - Agrostis pallens is a cool-season California native bentgrass, with a uniform growing habit, medium texture, and deep green color. Native bentgrass requires full sun, withstands foot traffic, and has a good wear recovery due to self repairing rhizomes. Native bentgrass can be either mowed or it can be left to flop, creating the look of a natural, informal meadow. If you want the look of a mowed lawn, you should continually mow it. If you let it get long and shaggy before mowing it low, it will have a scalped look until it has had time to grow back. The sod grower's irrigation trials indicate that Native Bentgrass requires about half the water of a traditional cool-season grass to keep the lawn green throughout the year. Starting a native bentgrass lawn from seed can be a challenge because it is slow to start. But it has recently been made available as sod with degradable netting from Delta Bluegrass Company in Stockton. The price of Native Bentgrass sod is more than that of traditional blue, rye, or fescue sods because it takes longer for the grower to produce. If cost is not the primary factor, a Native Bentgrass sod might make a great alternative to your conventional lawn. For more information on this California Native Sod, see http://www.deltabluegrass.com/blendcomparisonchart .
UC Verde Buffalograss - UC Verde is a variety of buffalograss which was developed by University of California researchers at Riverside and Davis as a lower water use alternative to the traditional cool and warm-season grasses. It is a warm-season grass native to the North American plains; it looks terrific during summer; and is soft on bare feet. But its main drawback is that in Northern California it goes fully dormant in the winter, turning straw-colored after a hard frost occurs. People often use a biodegradable green dye during the winter in order to maintain the appearance of a green lawn. UC Verde grows to only 4-6" tall and requires mowing only every 2-3 weeks. It is planted from plugs which are usually spaced 12 inches apart and should be planted early in the warm season (e.g. May) to give the lawn a chance to establish before the weather cools. It spreads by rhizomes and is very competitive with weeds once established. However, keeping the lawn weed-free until it becomes fully established is more challenging than installing sod, and may require an aggressive weeding campaign. UC Verde buffalograss requires 50% to 75% less water than the typical fescue lawn. For more information on growing and maintaining UC Verde buffalograss, including photos of the grass throughout the season, see http://cesacramento.ucanr.edu/Pomology/Turf_Demonstration_Project/Three_species_in_irrigation_trial/UC_Verde_buffalograss/ .
No-Mow Fineleaf Fescue – Fineleaf fescues are cool-season grasses which include red fescue, Chewings fescue, sheep fescue and hard fescue. Many new and improved fineleaf fescue species and cultivars have come to California in recent years. Fineleaf fescues can be either seeded or sodded. They typically require about 85% of the water needed to keep a typical lawn green in the summer but they can withstand more severe irrigation deficit and dormancy with the ability to come back the following year. Fineleaf fescue lawns can be kept to about 2 ½" by mowing every 2 to 3 weeks or they can be left to grow to a height of 6 to 12 inches to create a "natural" look by mowing 1 to 4 times per year. They are an aesthetically pleasing no-mow grassy groundcover, with lower water requirements, however, they are not suitable for areas where pedestrian traffic is common. For more information on fineleaf fescue, see the attached U.C. article "No-Mow Fineleaf Fescue Grasses for California Urban Landscapes" (http://anrcatalog.ucdavis.edu/pdf/8391.pdf).
Irrigation – Whichever grass you select, your irrigation system plays an important role in water conservation. Standard spray irrigation heads are not an efficient method of applying water. You might consider replacing conventional sprinkler nozzles with high-efficiency rotating or precision nozzles. Or perhaps install a below grade inline emitter system such as Eco-mat by Hunter irrigation http://www.hunterindustries.com/irrigation-product/micro-irrigation/eco-matr-and-pld-esd . Replacing traditional irrigation timers with weather-based models (smart controllers) can help to provide the amount of water actually required by the plant, and often results in water savings. If you are redoing you irrigation system, you might want to check out the water district's rebates, if any, for upgrading irrigation equipment and installing Smart Controllers (for EBMUD see http://www.ebmud.com/for-customers/water-conservation-rebates-and-services/lawn-conversion-irrigation-upgrade-rebates).
Good luck with your project. Feel free to contact us if you need additional information.
Contra Costa Master Gardeners' Help Desk
Note: The Contra Costa Master Gardener Help Desk is available year-round to answer your gardening questions. Except for a few holidays, we're open every week, Monday through Thursday for walk-ins from 9:00 am to Noon at 75 Santa Barbara Road, 2d Floor, Pleasant Hill, CA 94523. We can also be reached via telephone: (925) 646-6586, email: firstname.lastname@example.org, or on the web at http://ccmg.ucanr.edu/Ask_Us/