Irrigation trials on "Kurapia' from 2012-2014 performed at U.C. Davis found the plant's sturdy structure and low water needs makes it a "great option" for groundcover that won't get irrigated, suggesting it appropriate for highway and freeway shoulders, rooftops, public utility areas, commercial properties and solar farm landscapes. The photo shows a Kurapia groundcover installed by Caltrans for a stormwater bioswale project.
Photo: Eco Tech Services

During the fall of 2012, 24 #1-sized plants of Lippia nodiflora "Kurapia' were planted in the ground in full sun on the University of California campus in Davis, Calif. (USDA Zone 9b and Sunset zone 14). The field soil was characterized as Yolo clay loam, a fairly heavy soil. This was a two-year irrigation study performed by U.C. Davis/ UCANR; results were published in January 2015.

Kurapia was bred from the Japanese native coastal plant Lippia nodiflora. It has been found to be highly tolerant of saline, acidic and basic soils. It's also asserted that Kurapia requires little maintenance and needs less water than cool and warm season turfgrasses. Kurapia has an extensive root system and depending on the soil type, can reach a depth of 1 meter. This root system can be beneficial in reducing soil erosion and runoff. Its thick, dense growth helps suppress weeds and reduces the need for weeding.

 

This Kurapia lawn is at Scripps College in Claremont, Calif. For the Kurapia trials at U.C. Davis, one of the researchers, Karrie Reid, an environmental horticulture advisor for the U.C. Cooperative Extension (San Joaquin County), suggested homeowners may want to consider using it as a lawn replacement. Kurapia can tolerate light foot traffic, but is not recommended for heavy traffic areas like playgrounds or sports fields. Photo: Florasource Ltd.

For the research trials, the Kurapia plants were placed 2 meters apart in 1-meter wide planting beds covered with 3" of chipped wood mulch. Planted beds were separated by a 1 meter-wide nonmulched path between rows. Each row was supplied with 4 water lines corresponding to one of 4 irrigation treatments.

Research Feedback The researchers noted Kurapia's vigor. The plants quickly grew (an average of 16" across to 52" between April and November) and had to be cut back twice in two years.

For the "deficit irrigation" portion of the trials the second year, the growth and quality of the plant was not significantly affected. This irrigation level was to encourage the establishment of deep roots into the native soil. The cultivar showed extreme adaptability to irrigation levels. Because of its high performance level at the lowest irrigation rate in the trials, the researchers recommend that once established, it be irrigated at the 20% ET0 level, and no more than 40% level of ET0, as additional water does not represent a significant gain in appearance or size. These recommendations, the researchers specify, are based on using drip irrigation in a clay-loam soil, and may not be reproducible in lighter soils or with the use of overhead spray irrigation, note the researchers.

Kurapia has long blooming (May to November) small whites flowers that attract pollinators. The research noted the plant looks good year-round. The groundcover grows less than an inch high, and has a 6' spread. The flowers are sterile, i.e., unable to reproduce by seed.

Kurapia flowers, while not showy, are attractive when the plant is in full bloom, and heavily visited by pollinators. Kurapia was unaffected by disease during this trial, and only very minor leaf chewing by insects was observed. The plant was, however, affected by a December frost, with the edges dying; it began to recover in late March, and by April all the plants had grown back over the bare spots.

Plant Characteristics
Name: Lippia nodiflora L. "Kurapia'

Plant Type: Perennial
Soil: Highly tolerant of saline, acidic and basic soils
Growth Habit: Best to plant March to September. Small white flowers May to November. Low growing (less than 1" high); 6' spreading width.
Exposure: Full sun to part shade
Drought Tolerant: ETo 20% by drip irrigation; Eto 40% by sprinkler irrigation

pH range: 4-9

Temperature range: 20-120°F
USDA Hardiness Zones: 7b-13b