Posttransplant Irrigation Frequency Affects Growth of Container-grown Sweet Viburnum in Three Hardiness Zones

Abstract

<jats:p>The survival and quality of shrubs planted in the landscape from containers is dependent on irrigation to ensure the development of a healthy root system. This study determined the effect of irrigation frequency on survival, quality, canopy growth index, root to canopy spread ratio, and dry root and shoot biomass of <jats:italic>Viburnum odoratissimum</jats:italic> Ker-Gawl. (sweet viburnum) planted in Florida in USDA hardiness Zones 8b (Citra, FL), 9a (Balm, FL), and 10b (Ft. Lauderdale, FL). Sweet viburnum shrubs were planted into the landscape from 11.4-L (#3) containers and irrigated with 3 L every 2, 4, or 8 days. Shrubs were planted on eight dates over a 2-year period (2004 to 2006). Irrigation frequency during the 12- to 22-week irrigation period had no significant effect on sweet viburnum survival or aesthetic quality at any location. In addition, there was no irrigation effect on root spread, root to shoot biomass ratio, or root biomass for shrubs planted in Zones 8b or 9a. However, sweet viburnum irrigated every 2 days had greater canopy growth index at 28 and 104 weeks after planting than shrubs irrigated every 4 or 8 days in Zone 8b and every 8 days in Zone 9a. When planted in Zone 10b, sweet viburnum irrigated every 2 days exhibited greater growth index, shoot biomass, and root biomass than plant receiving irrigation every 4 days. Although more frequent irrigation (every 2 days) resulted in more plant growth in Zones 8b and 10b, sweet viburnum survived and grew after planting under natural rainfall conditions provided they were irrigated with 3 L of water every 8 days during establishment until roots reached the canopy edge in hardiness Zones 8b and 9a and every 4 days in hardiness Zone 10b. Subsequent supplemental irrigation (hand-watering) was only needed after irrigation was ended when plants exhibited visible signs of drought stress and there was no measurable rainfall for 30 consecutive days.</jats:p>

Native and Non-native Shrub Post-transplant Performance under Low-volume Irrigation in Three Hardiness Zones

“…Results of our study show that additional shrub species can be established in the predominantly sandy soils of the Florida landscape in USDA hardiness zones 8b, 9a, and 10b when following the irrigation recommendations for plant vigor published by Shober et al (2009. A total of 21 commonly planted native and non-native landscape shrubs was established using these procedures.…”

“…Each emitter was mounted 4 inches above ground level with an emitter located on the east and west side of each plant, 6 inches from the outside of the root ball, and the third emitter was positioned on the root ball. Irrigation frequencies were controlled as separate zones as described by Shober et al (2009). Irrigation was ended 20 weeks after transplant, after which time supplemental irrigation (3 L per plant by hand) was supplied to all shrubs for a specific planting date over the 2-year post-planting period when signs of severe water stress, such as severe foliage wilting, were observed.…”

“…Six replicates of each shrub species were planted into level plots at each site. Shrubs were installed on the two following planting dates at each site: Dec. 2006 (USDA hardiness zones 8a and 10b) or Dec. 2007 (zone 9a), and June 2007 (zones 8a, 9a, and 10b) as outlined in Shober et al (2009). Shrubs were grouped in the field by planting date.…”

Nitrogen Fertilizer Rate, Timing, and Application Method Affects Growth of Sweet Viburnum and Nitrogen Leaching from Simulated Planting Beds

“…Starting 16 May 2012, each individual plant was irrigated with 4.35 L of water twice per week directly on the root ball through two spray stakes (Netafim USA., Fresno, CA) spaced 38 cm apart. The irrigation volume was selected to ensure water stress was not an issue and to prevent irrigation driven leaching based on the results of previous research where irrigation with 3 L of water directly to the roots every 4 to 8 d was sufficient to successfully establish sweet viburnum in the landscape following transplant Shober et al, 2009b). Precipitation data were collected using the Florida Automated Weather Network station that was located on-site.…”

Water Conservation Benefits of Long‐Term Residential Irrigation Restrictions in Southwest Florida

“…It was assumed that each landscape consisted of 79% well‐watered turfgrass and 21% ornamental plant beds (Haley & Dukes ). The irrigation requirement of the ornamental plant beds, which typically don't need supplemental irrigation after six to 12 months of planting, was assumed to be zero (Shober et al , Scheiber et al ).…”