The foliage provides year-round interest in its hardiness zone. It flowers from June to July and fruits from September to November. If you want to encourage flower and fruit production rather than excess foliage growth, try restricting the growth of the spreading root suckers. Growing it in a container works well in these instances. Purple passionflowers are highly flammable plants, so it won’t be the best choice for growing up against your home in areas at risk of wildfires.
Light
Purple passionflowers thrive in full sun but can also tolerate a part shade position.
Soil
Purple passionflowers aren’t fussy when it comes to soil and adapt well to most types (including extremely poor soils), providing they are well-drained and moist. It might even get a little out of control in highly fertile soils.
Water
This climbing vine can handle drought conditions, but keep the soil consistently moist for the best chance to appreciate the beautiful blooms. Slow, deep watering at root level is best. Applying a few inches of loose mulch at the roots can help to retain moisture, especially when conditions are dry. Just make sure the mulch doesn’t press up against the plant stem.
Temperature and Humidity
These tropical-looking flowers are surprisingly cold-tolerant. Providing your purple passionflower is planted in well-drained soil, the roots should be hardy down to around -5 degrees Fahrenheit. While the top growth dies off in these freezing temperatures, the plant will stay healthy if you mulch the roots. In warmer climates, this evergreen remains woody.
Fertilizer
Regular light feeding helps ensure your purple passionflower blooms prolifically. Select a fertilizer that isn’t too heavy in nitrogen; otherwise, growth will focus on the green foliage rather than the flowers. Fertilize in the early spring before the emergence of new growth. Once the flowers appear, feeding at least once a month or more through to early fall is ideal for these heavy feeders.
Pruning
You won’t need to prune purple passionflowers regularly. However, if you want to encourage a full, bushy appearance and prevent your climbing vine from looking straggly, it helps to pinch back the plants in their first growing season. In cooler climates, cutting back the top growth annually is common as the plant is treated as a herbaceous perennial rather than a woody evergreen. Because flowering occurs on new growth, pruning should be done in late winter or early spring to ensure new blooms still appear in abundance later in the spring.
Propagating Purple Passionflowers
It’s possible to propagate purple passionflowers via various methods, including taking softwood stem cuttings, tip layering, and growing from seed. To propagate from stem cuttings, try following the steps below: If you want to create a new plant in the same location as the original, you can try propagation by tip layering. This involves bending a stem of the existing plant to the ground, covering it in soil, and waiting to see if a new shoot will develop. Trying this method in late summer or early fall is best, and following the tips below can help maximize the chances of success.
How to Grow Purple Passionflowers From Seed
You can propagate purple passionflowers from seed, although it is a little more tricky than propagating from cuttings, and germination is slow. It typically takes two to three months but can take up to a year. Try following the steps below in late winter or early spring:
Potting and Repotting Purple Passionflowers
Because purple passionflowers are such heavy feeders, even with fertilizers, your plant will exhaust the nutrients in the pot after a few years. At this point, it’s a good idea to repot in a container at least a few inches bigger than the current one. Make sure the pot has good drainage holes and that the medium you use is fertile and well-drained.
Common Pests & Plant Diseases
One of the appeals of the purple passionflower is its moderate resistance to deers, pests, and diseases. However, pests such as scale insects, spiders mites, and whiteflies might be a problem in humid and warm climates. Root rot can also be an issue if your plant is in soil with poor drainage.
How to Get Purple Passionflowers to Bloom
The purple passionflower’s exotic, fragrant summer blooms are around 1 to 3 inches wide and typically only bloom for a day. Loose, hanging vines are more likely to produce blooms, so don’t try to train your plant too formally. Because they are heavy feeders, if you don’t get the nutrient levels right, you might be disappointed by how many blooms appear.
