The 2012 ASHS Annual Conference

Increased use of native wildflowers for landscapes supports the need for effective propagation, production and establishment methods.  Over the years, a number of containerized media substrates have been developed for improved drainage, root distribution and plant growth.  Coastalplain honeycombhead (Balduina angustifolia), Florida scrub roseling (Callisia ornata), Bush goldenrod (Chrysoma pauciflosculosa), Godfrey’s goldenaster (Chrysopsis godfreyi), Feay’s prairieclover (Dalea feayi), gopher apple (Licania michauxii), Largeleaf jointweed (Polygonella macrophylla), October flower (Polygonella polygama), and Largeflower jointweed (Polygonella robusta) were transplanted into containers filled with one of four commercially available media for 16–20 weeks.  The four media treatments (Atlas 3000, Atlas 7000, Fafard 3B, and Metro Mix 300) consisted of varying percents of peat, pine bark, vermiculite, perlite, sand, cypress dust and bark ash with physical and chemical properties ranging from 48-76% moisture content, 3.3% to 5% air filled porosity, 60% to 68% total porosity, 55% to 61% container capacity, 0.13–0.55 g·cm³ bulk density, 0.33–1.3 g·cm³ particle density, 5.8–6.9 pH, 0.09-0.79 mmhos∙cm electrical conductivity (EC), and 2.9–14.5 meq∙100g ^-1 cation exchange capacity (CEC). Atlas 7000 contained the lowest initial nutrient composition.  After 12–16 weeks in the greenhouse, a media treatment effect was observed for plant height of Balduina angustifolia, Callisia ornata, and Chrysopsis godfreyi.   Plants were transplanted within treatments to the landscape and evaluated monthly for flowering and performance for 40 weeks (March-January).  Survival, performance and flower duration varied by treatment and species.  Overall, plant survival was poorer for species grown in the Atlas 3000 mix.   Among the nine wildflower species evaluated, each has unique ornamental potential for native landscapes, offering a range of flower times and colors.  Media substrate composition can extend the visual quality of some species, but other species such as Balduina angustifolia and Polygonella robusta should simply be used as shorter term annuals.