Complex, 4″ flowers keep coming all summer and don’t stop until the first frost. This vigorous vine will grow stems to 30′, covering a 10′ stretch of fence, or a nice-sized trellis. Can be grown in the ground or in a large container, which can be brought indoors to a cool sunny place to overwinter north of zone 6. Prune 1/2 the stems hard in early summer, and tip prune the rest. Flowers best in well-drained, gritty soil that’s not too fertile. Passiflora caerulea. Full Sun.