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Home HortTechnology Using Controlled-release Fertilizers with Herbaceous Perennials
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HAMMOND, LA—Use of controlled-release fertilizers (CRF) is often recommended to landscape industry professionals as a best management practice for establishing landscape plants. Previous research has shown that the use of CRF can improve plants' nutrient use efficiency and minimize nitrogen (N) leaching. New research from scientists at Louisiana State University Agricultural Center provides professionals with important new information about CRF usage with popular herbaceous perennials.

Yan Chen, Regina Bracy, Allen Owings, and Joey Quebedeaux from LSU Ag Center's Hammond Research Station published the results of the CFR experiments in HortTechnology. The team designed their experiments to determine optimum CRF recommendations for establishing commonly used herbaceous perennials in an amended landscape bed.

The scientists chose popular perennials cigar plant, daylily, gaura, lantana, mexican heather, purple coneflower, and rudbeckia for their study. "These perennials were selected with the intention of comparing their nutritional needs and determining whether they can be grouped by size or growth pattern for fertilization practice," said lead author Yan Chen.

Two controlled-release fertilizers were used in the study: Granular Osmocote®Plus 15N–3.9P–10K (7% ammoniacal and 8% nitrate nitrogen) and Tablet Osmocote®Plus 16N–3.5P– 10K 7.5 g (7.5% ammoniacal and 8.5% nitrate nitrogen). The seven varieties of perennials were subjected to six fertilizer treatments. According to the report, plant size, and visual quality at 5 months after transplant were improved by fertilization for all perennials except 'Stella de Oro' daylily.

The study details the effects of fertilizer treatments on all seven perennials. "Based on our results, we recommend applying two tablets (7.5 g) of 16N–3.5P–10K Osmocote®Plus per plant at transplant to establish all of the perennials tested in this study," Chen said. The researchers also discovered that, while the larger plants used in the study may have grown more under higher fertilization rates, the plants did not necessarily increase in quality.

The team added that further research is needed to determine the effects of CRF application on the overwinter survival of herbaceous perennials and appropriate uses of CRF for various soil profiles to enhance nutrient use.


The complete study and abstract are available on the ASHS HortTechnology electronic journal web site:

Founded in 1903, the American Society for Horticultural Science (ASHS) is the largest organization dedicated to advancing all facets of horticultural research, education, and application. More information at


Original Article:

Controlled-release Fertilizer Type and Rate Affect Landscape Establishment of Seven Herbaceous Perennials
Yan Chen, Regina P. Bracy, Allen D. Owings, and Joey P. Quebedeaux
HortTechnology 21:336–342. [Abstract][Full Text][PDF]

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