Passion flowers, known botanically by their genus, Passiflora, are subtropical flowering and fruiting vines that climb up and twine around virtually any structural support. Generally hardy only down to USDA Zone 8, passion flowers are often killed to the ground over the winter and are vigorous enough to grow back to size, flower and fruit during the spring and summer. Once plants are established in the soil they should start flowering that first summer. A lack of bloom performance usually comes down to improper care and maintenance and can easily be corrected.
Water the plants consistently every four to seven days in order to keep the soil evenly moist, but not soaking wet, at all times. Do not let the soil ever dry out beyond the top 1/4-inch of soil crust. High heat, direct sun, low humidity or very sandy soil may necessitate more frequent watering intervals.
Fertilize your Passiflora vines with a low-nitrogen fertilizer product to keep them vigorous. Use a product with a guaranteed analysis of 10-5-20 or a similar ratio of nitrogen, phosphorus and potassium. Apply three pounds of fertilizer around the base of each plant four times a year in the early spring, early summer, midsummer and fall. Ensure that there is no leaching of high-nitrogen fertilizers such as those applied to nearby lawn grass, as these will thwart flowering.
Prune your passion flower vines in the early spring just after the last frost or in the fall after fruiting. Pruning during the later spring or summer will cut off flower buds, preventing a proper bloom cycle. Remove all dead plant tissue and roughly one-third of the plant volume each year to spur new flowering and fruiting growth.
Protect the plants from winds, as they can lead to bud drop and reduce or prevent a proper bloom cycle.
Things You Will Need
- 10-5-20 fertilizer
- Pruning shears
- Wind protection