Mountain laurel is an evergreen flowering shrub in the heath family ( Ericaceae ) that occurs throughout temperate areas of the world ( Jaynes, 1988 ). Mountain laurel is native to the eastern United States, specifically from southern Maine west
He Li, Matthew Chappell, and Donglin Zhang
Ole Billing Hansen and John R. Potter
Dormant stock plants of apple (Malus domestica Borkh.) rootstocks M.26 and Ottawa 3; Rhododendron `Britannia', `Purple Splendour', and `Unknown Warrior'; and mountain laurel (Kalmia latifolia L.) `Ostbo Red' and seedlings were forced to grow at 18 or 28 °C in continuous darkness or 14-h photoperiods. Etiolated shoots were then acclimated to light with or without aluminum foil wrapped around their bases to keep the bases etiolated. Shoots forced in diurnal light were neither etiolated nor wrapped and served as controls for the etiolation treatments. Compared to controls, wrapping etiolated stems improved rooting of M.26 (60% vs. 82%) and `Ottawa 3' (81% vs. 97%) apple and of `Britannia' (76% vs. 90%) and `Unknown Warrior' (80% vs. 91%) rhododendron. Etiolation improved rooting percentage of `Unknown Warrior' regardless of wrapping. Regardless of etiolation, forcing `Ottawa 3' at 18 °C improved rooting percentage (92% vs. 74%) and roots per cutting (12 vs. 7) compared to forcing at 28 °C. Etiolated mountain laurel cuttings generally rooted best at 18 °C; control cuttings rooted best at 28 °C.
Asiah A. Malek, Frank A. Blazich, Stuart L. Warren, and James E. Shelton
Seedlings of mountain laurel (Kalmia latifolia L.) were grown for 16 weeks under long-day conditions with days at 18, 22, 26, or 30C for 9 hours in factorial combination with nights at 14, 18, 22, or 26C for 15 hours. Total plant dry weight, top dry weight, and dry weights of leaves, stems, and roots were influenced by day and night temperatures. The night optimum for all dry weight categories was 22C. Dry matter production was lowest with nights at 14C. Total plant dry weight and dry weights of tops, leaves, and stems were maximized with days at 26C, but for roots the optimum was 22C. Dry weight accumulation was lower with days at 18 or 30C. Responses of leaf area were similar to that of total plant dry weight, with optimum days and nights at 26 and 22C, respectively. Within the optimal day/night temperature range of 22-26/22C for dry weights, there was no evidence that alternating temperatures enhanced growth. Shoot: root ratios (top dry weight: root dry weight) increased with day temperatures up to 30C and were highest with nights at 14 or 26C. Leaf weight ratio (leaf dry weight: total plant dry weight) decreased with increasing night temperature, and increased curvilinearly in response to day temperature with the minimum at 26C. Stem weight ratio (stem dry weight: total plant dry weight) increased with increasing day or night temperature. Root weight ratio (root dry weight: total plant dry weight) was highest with nights at 18 or 22C and decreased with days >22C. Net leaf photosynthetic rate was maximized with days at 26C.
He Li and Donglin Zhang
Kalmia latifolia L. (mountain laurel), a member of Ericaceae (heath family), is a large evergreen flowering shrub native to the eastern United States. It has been considered by many horticulturists and gardeners to be one of the most beautiful
Julie Guckenberger Price, Amy N. Wright, Robert S. Boyd, and Kenneth M. Tilt
ball down to the surrounding soil grade. More root growth occurred in shrubs of the very difficult to transplant species mountain laurel planted with this technique than in those planted at-grade with PB amended backfill or at-grade with NOM ( Wright et
Amy N. Wright, Stuart L. Warren, Frank A. Blazich, and Udo Blum
The length of time between transplanting and subsequent new root initiation, root growth rates, and root growth periodicity influences the ability of woody ornamentals to survive transplanting and become established in the landscape. Research was conducted to compare root growth of a difficult-to-transplant species, Kalmia latifolia L. (mountain laurel), to that of an easy-to-transplant species, Ilex crenata Thunb. (Japanese holly), over the course of 1 year. Micropropagated liners of `Sarah' mountain laurel and rooted stem cuttings of `Compacta' holly were potted in 3-L containers. Plants were grown in a greenhouse from May to September, at which time they were moved outside to a gravel pad, where they remained until the following May. Destructive plant harvests were conducted every 2 to 4 weeks for 1 year. At each harvest, leaf area, shoot dry weight (stems and leaves), root length, root area, and root dry weight were determined. Throughout the experiment, shoot dry weight and leaf area were similar for the two species. New root growth of `Compacta' holly and `Sarah' mountain laurel was measurable 15 and 30 days after potting, respectively. Root length and root area of `Sarah' mountain laurel increased during May through December but decreased during January through May. Root length and root area of `Compacta' holly increased linearly throughout the course of the experiment. Final root: shoot ratio of `Sarah' mountain laurel was one-ninth that of `Compacta' holly. Results suggest that poor transplant performance of mountain laurel in the landscape may be related to its slow rate of root growth.
Julie Guckenberger Price, Amy N. Wright, Kenneth M. Tilt, and Robert L. Boyd
.3 L) from Greene Hill Nursery, Inc. in Waverly, AL, and five seedling Kalmia latifolia L. (mountain laurel) (19 L) from Dodd and Dodd Nursery, Inc. in Semmes, AL, respectively, were removed from their containers and placed in the center of
Genhua Niu, Denise S. Rodriguez, and Mengmeng Gu
., 2005 ; Niu et al., 2007 ). Texas mountain laurel is an evergreen shrub or small tree native to Texas, New Mexico, and northeastern Mexico. Mexican redbud is a native, deciduous small tree. It is heat- and drought-tolerant and thrives in well
Genhua Niu, Denise Rodriguez, and Mengmeng Gu
Texas mountain laurel ( Sophora secundiflora ), also called mescal bean, is a small evergreen tree native to Texas, New Mexico, and north Mexico. Its ornamental characteristics include terminal racemes of fragrant, violet–blue flowers in the spring
Mark H. Brand
The effect of shading during nursery production on the growth, foliage color, and foliar chlorophyll content of container-grown Kalmia latifolia cultivars was investigated. Five cultivars were grown under 40% shade, 60% shade, or full sunlight for a 2-year production cycle. During the first year of production, there were no significant differences in measured growth characteristics for most cultivars in response to light treatment. Shade improved foliar color by decreasing lightness (L*), decreasing chroma, and changing hue angle from a yellow-green to a darker green. Foliar chlorophyll concentration increased under shade. In the second year of the production cycle, the response of foliar color and chlorophyll concentration to shade was similar to that observed in year 1. Plant size, number of branches, leaf area, leaf dry mass, and stem dry mass decreased linearly with increasing shade in year 2. Although shading improves foliar color, it probably should not be employed for container production of Kalmia latifolia in cool, northern production areas due to reduced plant growth during year 2. Shade may be useful in the first year of production to enhance foliar color without reducing shoot growth.