Evaluation of 14 Butterfly Bush Taxa Grown in Western and Southern Florida: I. Visual Quality, Growth, and Development

Abstract

<jats:p>Plant growth, visual quality and flowering were assessed for 14 butterfly bush (<jats:italic>Buddleja</jats:italic>) taxa planted in western Florida (Milton) and central southern Florida (Fort Pierce). In both locations, `Violet Eyes' butterfly bush (<jats:italic>B. weyeriana</jats:italic> × <jats:italic>B. lindleyana</jats:italic>), `Honeycomb' butterfly bush (<jats:italic>B.</jats:italic> × <jats:italic>weyeriana</jats:italic>), `Moonlight' butterfly bush (<jats:italic>B.</jats:italic> × <jats:italic>weyeriana</jats:italic>), and `Sungold' butterfly bush (<jats:italic>B.</jats:italic> × <jats:italic>weyeriana</jats:italic>) generally had the greatest growth index and shoot dry weight of all cultivars. In Fort Pierce and Milton, flower dry weights of `White Profusion' butterfly bush (<jats:italic>B. davidii</jats:italic>), `Nanho Alba' butterfly bush (<jats:italic>B. davidii</jats:italic> var. <jats:italic>nanhoensis</jats:italic>), and `Dartmoor' butterfly bush (<jats:italic>B. davidii</jats:italic> × <jats:italic>B. davidii</jats:italic> var. <jats:italic>nanhoensis</jats:italic>) were among the highest as compared to other cultivars at each site, although in Milton, `Gloster' butterfly bush (<jats:italic>B. lindleyana</jats:italic>), japanese butterfly bush (<jats:italic>B. japonica</jats:italic>) and `Honeycomb' butterfly bush also had high flower dry weights. Peak plant performance varied by month, cultivar and location. At 12 weeks, plant form and color were above average for each cultivar with the exception of `Black Knight' butterfly bush (<jats:italic>B. davidii</jats:italic>), lindley's butterfly bush (<jats:italic>B. lindleyana</jats:italic>), and `Gloster' butterfly bush in the Fort Pierce location only. After 24 weeks at each location, visual quality was above average for `Black Knight', `Dartmoor', `Gloster', `Honeycomb', `Violet Eyes', and japanese butterfly bush. Peak flowering times varied with cultivar and location. At 24 weeks, flowering of `White Profusion', `Nanho Alba', `Nanho Blue', and `Nanho Purple' butterfly bush grown in Fort Pierce was 25% to 40% less than that of the same cultivars grown in Milton. At 24 weeks, `Dartmoor' had the most flowers in both locations, covering 75% of the plant canopy.</jats:p>

The Invasive Buddleja davidii (Butterfly Bush)

“…The absence of self-pollination has been linked to the heavy allocation of resources to insect attractants in other species, which is consistent with the presence of conspicuous flowers, pungent scent and abundant nectar in B. davidii (Miller, 1984;Houghton et al, 2003). A single mature B. davidii individual can produce millions of seeds; however, estimates of the number of seeds produced vary (100,000 to 3,000,000) among B. davidii cultivars (Miller, 1984;Brown, 1990;Wilson et al, 2004b;Thomas et al, 2008c). Seed formation and ripening typically occurs within 3 weeks after flowering (maturing in the autumn; Miller, 1984;Stuart, 2006).…”

“…davidii breeding programs began as early as 1920, when W. van de Weyer developed interspecific hybrids resulting from crosses between B. globosa and B. magnifica (Moore, 1960;Wilson et al, 2004a). Since that time, cultivars have been bred for size, a variety of flower colors and environmental hardiness for the nursery trade.…”

“…1e) are brown, narrowly ellipsoid to narrowly ovoid, 5-9×1.5-2 mm, acute at the apex, narrowed towards the base, mostly 3-4 times as long as the calyx, and are often smooth, or have stellate hairs (Zheng & Raven, 1996;Wilson et al, 2004b). The capsule has an impressed line along the line of dehiscence (Leeuwenberg, 1979).…”

“…Seed dispersal may take place over an extended period of time depending on the conditions (Miller, 1984;Wilson et al, 2004b). Seeds dispersed prematurely were confirmed to be less viable than those retained in the capsule (Miller, 1984).…”

“…davidii is a widely cultivated and popular garden plant of economic value to the horticultural industry (Turnbull, 2004;Wilson et al, 2004a). Certain B. davidii cultivars were worth over $200,000/year to Georgia, USA, plant growers (Dirr, 1997).…”