After the back-to-back Kona -low storms that brought lots of rain and some major flooding events to 91直播, it might be time to find some ways to minimize damage in future floods. From local farmers I learned that damage can be somewhat mitigated if you plan (and plant) ahead. One of the best plants to consider in your planning is vetiver grass.
This deeply rooted tropical grass has been used for centuries throughout the world as a 鈥渉edge鈥� against erosion and landslides. Native to India, vetiver (Chrysopogon zizanioides) is a perennial bunchgrass in the Poaceae or grass family.
In the United States, the sterile cultivar commonly grown here was named 鈥淪unshine鈥� by the USDA in 1989. It was named for the town Sunshine, Louisiana, which is near Baton Rouge along the Mississippi River. This heritage clone was grown and used in Louisiana since the 1860s and given to Eugene LaBlanc Sr. by his grandparents. He continues to cultivate it on his Louisiana farm.
Nearly all of the vetiver grown worldwide is the Sunshine cultivar. It is sterile and noninvasive. It can only be propagated vegetatively by slips or the small offsets it produces. It does not produce underground stolons, so it stays where it鈥檚 planted.
Vetiver slips can be removed from mature clumps for propagation. These are available for purchase or from your plants of those of friends or neighbors. They should be planted in a sunny location about 4 inches apart along a slope or next to a swail where flood water flows. For the first few months, the new plants will need to be watered lightly. Once established, this grass is very drought tolerant.
Within six months the stems will grow over a foot tall and the roots will likely have penetrated a few feet into the soil. You鈥檒l have a dense vetiver hedge in about a year with strong leaves and stems that can hold soil and even gravel on a slope. By that time, the plants will have produced a mass of fibrous roots that are anchoring the soil five feet or more below the surface.
Vetiver plants can grow up to eight feet tall and form clumps around two feet in diameter as they mature. The leaves are long, thin, and stiff forming a green wall to hold the slope or water鈥檚 edge. In addition, mature plants will have produced a tangled wall of root mass that can go as deep as twenty feet into the soil. These strong roots will also hold in moisture and nutrients that might otherwise get washed away.
Planting several rows of vetiver about 18 inches apart creates hedges that can increase the water and debris holding efficacy of the installation. These hedges are highly effective at slowing down fast-moving water and trapping debris that is moving with the water.
Though just keeping your topsoil in place or protecting your land from erosion by wind, rain, floods or rising surf is an increasing challenge here in 91直播, choosing to plant vetiver grass can help prevent and mitigate this damage.
In addition to vetiver鈥檚 erosion control properties, it is also an attractive landscape grass for edging and defining borders. It is fast growing and the thin stiff leaves can be trimmed to a desired height. Trimmings can be used as mulch or biomass in your garden. After about nine months, some vetiver plants will put out lavender flower heads. Vetiver flowers do not set seed, however.
Vetiver is closely related to sorghum and shares aromatic properties with several fragrant grasses including lemongrass and citronella grass. Vetiver鈥檚 aromatic quality is in the roots, however. The 鈥楽unshine鈥� cultivar鈥檚 roots have long been used in Louisiana as an insect repellant.
In many parts of the world, the roots are woven into fragrant mats or blinds. The roots can also be steeped into a tea. Steam-distillation of the roots produces an essential oil that has an earthy somewhat smoky aroma that some compare to patchouli oil. Vetiver oil is used in aromatherapy as well as for a variety of medicinal purposes and as an ingredient in perfume.
Vetiver is a very tolerant plant making it an attractive choice for a landscape. It can tolerate a wide variety of climatic conditions including dry deserts and wet marches. It is salt, wind and fire resistant. It can be grown in sand and will penetrate and loosen dense or compacted soils. It has also been grown to successfully remove contaminants from soil. And, it is disease and pest resistant. Vetiver鈥檚 versatility is legendary.
Go online to learn more about this very versatile plant. Check out vetiversystems.com for information on growing vetiver in 91直播. You can order slips from them online through their contact email or by calling owner Mary A. Wilkowski at (808) 398-5434. She is an associate director of the International Vetiver Network and is very knowledgeable about this wonderful plant. The vetiver network鈥檚 website vetiver.org also contains vast amounts of information on vetiver. Do think about planting vetiver to protect your property from the next heavy rain event.
Gardening events
Current: 鈥淜ona typica鈥� grafted trees available for purchase. First come, first served basis. 20 鈥淜ona typica鈥� grafted (on C. liberica rootstock) trees are available for $15 each.
Tissue cultured 鈥淚to鈥� trees available at $15 each. Contact Andrea at andreak@hawaii.edu if you are interested.
Still available: CLR Resistant Coffee Trees. Go to https://youtu.be/11-vtPT2jRU or call 808-322-4892.
April 7: Current, common fruit growers鈥� challenges and solutions.
鈥� Apr. 14: Updates on HARC鈥檚 coffee breeding program.
A single registration gives access to the series鈥� Zoom link. Contact Andrea Kawabata for flyer and registration information at (808) 322-4892 or andreak@hawaii.edu.
The series鈥� Zoom link is available at www.hawaiicoffeeed.com/2026webinars.html.
Continuing: Ka鈥榰 Coffee Farm Field Day Events, 11 a.m. to 1 p.m. In-person events:
鈥� April 23: Nutrition and fertilizing field day.
鈥� May 21: Sanitation and desuckering field day.
鈥� June (TBD): Mid-season sanitation and desuckering field day.
All are free events. Lunch included for registrants. Spanish translator on site. Register at www.91直播CoffeeEd.com/kau. Contact Matt at (808) 322-0164 with questions.
Book a booth now for Saturday, May 2, event: Be a vendor at Big Island International Fruits Festival from 10 a.m. to 4 p.m. in downtown Kona at Hale Halawai Beach Park on Ali鈥榠 Drive. Local Arts &Crafts and Food Vendors are invited to this free family event for the community. Contact Randyl Rupar at randyldna@earthlink.net or at (808) 936-5233 for forms or go to hawaiianwellness.com/events to download forms.
Farmer direct markets
Wednesday: Ho鈥榦ulu Farmers Market at Sheraton Kona Resort and Spa at Keauhou Bay.
Saturday: Keauhou Farmers Market, 8 a.m. to noon at Keauhou Shopping Center. Information on their online market at keauhoufarmersmarket.com/onlinemarket.
Kamuela Farmer鈥檚 Market, 7:30 a.m. to noon at Pukalani Stables.
Waimea Town Market, 7:30 a.m. to noon at the Parker School in central Waimea.
Waimea 91直播stead Farmers Market, 7:30 a.m. to noon at the Waimea Middle and Elementary School playground.
Sunday: Pure Kona Green Market, 9 a.m. to 2 p.m. at Amy Greenwell Garden in Captain Cook.
Hamakua Harvest, 9 a.m. to 2 p.m. at Hwy 19 and Mamane Street in Honoka鈥榓.
Plant advice lines
Anytime: konamg@hawaii.edu
Tuesdays and Thursdays: 9 a.m. to noon at UH-CES in Kainaliu, (808) 322-4893. Or walk in Mondays, Tuesdays and Fridays 9 a.m. to noon at UH CES at Konohana in Hilo, (808) 981-5199.
Diana Duff is a plant adviser, educator and consultant living on Oahu and working part time in Kona.