Sand backfill improves transplant success of some landscape palms

The Issue

Imparting an exotic and dramatic theme, palms are emblematic of California landscapes. Indeed, there is a revival of interest in palms as specimens and accents or to add height, dimension, and architectural interest for homes, businesses, parks and other public areas.

Because of their unique root and trunk structure, large specimen palms can be transplanted with a relatively small root ball, creating an instant, mature landscape. The standard industry practice when transplanting palms is to use builder's or washed plaster sand as the backfill medium in order to enhance stability and anchorage, drainage and survival, but the practice had not been scientifically validated.

What Has ANR Done?

Project leader Donald Hodel, with fellow advisors James Downer and Dennis Pittenger, designed and implemented an 18-month project at the UC South Coast Research and Extension Center in Irvine. Ten established specimens each of king palm, queen palm and Chinese windmill palm existing at the center were dug up and replanted a short distance away using either builder's sand or native site soil as the backfill medium. Growth parameters - including color, wilt and number of new leaves - were recorded 1, 6 and 12 months after transplanting.

The Payoff

UC research helps secure investment in mature palms

The results of this study suggest that sand backfill improves transplant success for most species of palms. With king and windmill palms, sand backfill enhanced color, reduced wilt, increased leaf production and improved survival. In contrast, sand backfill was not beneficial when transplanting queen palms.

The results validate the industry practice of using sand as the backfill medium when transplanting most types of palms. Because specimen palms represent a significant financial investment, their rapid and successful establishment following transplanting is a paramount economic benefit.

Contact

Supporting Unit:

Los Angeles County UC Cooperative Extension, UC Riverside, UC South Coast Research and Extension Center
 
Donald R. Hodel, drhodel@ucdavis.edu, (323) 260-3405