2018 ASHS Annual Conference

Native plants have significantly increased in popularity over the last few years due to the demand for more environmentally suitable urban landscapes that are low maintenance (reduced water, fertilizer and pesticides), tolerant of Florida’s climate, and beneficial in supporting wildlife and pollinators. Consumers are also increasingly aware of the threat non-native invasive species pose to Florida’s ecosystems and are seeking native alternatives.

Balduina angustifolia (Coastal Honeycombhead) is native to most of Florida and the coasts of Alabama, Georgia and Mississippi. It is characterized as an herbaceous annual/biennial having green linear foliage, bright yellow ray and disk flowers, and persistent, honeycomb-shaped seed heads. Due to its charismatic nature and fall flowering time, Balduina angustifolia is a suitable candidate for introduction into the commercial ornamental plant industry. It is also an important pollinator species, attracting a number of butterfly and bee species, including the Florida endemic balduina bee (Hesperapis oraria).

The objective of this research was to evaluate the germination, flowering, and landscape performance of Balduina angustifolia under varying conditions. For the germination experiments, seeds were collected from two sites in the Florida Panhandle (Perdido Key and Navarre Beach) after overwintering on the plants. Pre-germination viability tests indicated that seeds averaged 76% viability. Germination was evaluated for 28 days at four different alternating temperature regimes: 20°C/10°C, 25°C/15°C, 30°C/20°C, and 35°C/25°C with a 12 hr photoperiod. Highest germination (79%) was achieved at 30°C/20°C with seeds from Navarre Beach.

Germinated seedlings from a south Florida population were finished in one gallon pots and transplanted in three trial sites located in north (Gainesville), northwest (Milton), and south (Fort Pierce) Florida. Visual quality and flower intensity were evaluated monthly for 40 weeks, beginning in July. Peak flowering was observed in September for north and south Florida and in October for northwest Florida. Overall, visual quality was best for plants located in northwest Florida, followed by north Florida and then south Florida. Regardless of location, plants declined by December and did not recover the following spring. Results indicate that Balduina angustifolia would make an excellent addition to a fall garden or urban landscape.