Wisteria Blue - Climbing Flowers. A climber with branches reaching up to 33 feet in length (10m). An abundance of hanging pendants of blue flowers for cascading over railings and pergolas. Soak the seeds during 24 hours in water. Sow from February to March or October to November under glass. The plant is frost hardy to minus 15°C. Blooms from April to June. Buzzy Climbing Flowers Collection.