How to Grow Purple Passionflower (Passiflora Incarnata)

Purple passionflower (Passiflora incarnata), commonly called maypop for the sound made when stepping on it, is a fast-growing, evergreen, and tendril-climbing vine. Purple passionflower is the hardiest of the passionflower species, best grown in full sun and well-draining, moist soil. When protected with mulch, it can handle cold snaps down to -5 degrees Fahrenheit. It makes fragrant flowers from June to July, attracting pollinators, and produces passion fruits from September to November.

Purple Passionflower Care

Here are the main care requirements for growing a purple passionflower:

• Place plant in full or partial sun.
• Prefers moist, well-draining soil.
• Handles acidic or neutral pH soil.
• Give fertilizer regularly for prolific blooms.
• Layer soil with mulch if temperatures drop below freezing.
• Refrain from planting alongside a home since they are highly flammable plants, increasing wildfire risk.
  

Light

Purple passionflowers thrive in full sun but can also tolerate a part shade position.

Soil

Purple passionflowers aren't fussy regarding soil and adapt well to most types (including extremely poor soils), provided 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 the 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. Plant your purple passionflower 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 development. Once the flowers appear, feed at least once a month or more up through early fall. For the amounts to use, follow product label instructions.

Types of Passionflowers

There are hundreds of varieties of passionflower, coming in different colors and sizes. The care instructions are roughly the same. The foliage provides year-round interest in its hardiness zones. The plants also provide a nutritious source of winter food for wildlife.

Among its interesting facts, the southeastern U.S. native (P. incarnata) was cultivated for its orange-yellow edible fruits (passion fruit) by the Indigenous people in the United States. Its flowers, berries, roots, and leaves contain natural components historically used in folk medicine. An additional benefit of the plant is that it's a commercial crop; the flesh and juice of the fruits are eaten in Latin America, Asia, Hawaii, Africa, and Australia.

Here are a few passionflower types to try"

• Passiflora caerulea: Blue passionflower
• Passiflora coccinea: Red passionflower
• Passiflora alata: "Ruby Star,' fragrant granadilla, commonly known as passion fruit, is native to southern Brazil.
• Sweet granadilla (Passiflora ligularis); Grown in Africa and Australia

Pruning

You won't need to prune purple passionflowers regularly. To encourage a full, bushy appearance and prevent your climbing vine from looking straggly, pinch back the plants in their first growing season. Cut back the top growth annually in cooler climates where it's marginally hardy, and treat it 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 appear in abundance later in the spring.

This twining vine is ideal for growing up against trellises, outbuilding walls, or fences. Because it attaches with tendrils, it won't cause damage to brickwork the way plants with aerial roots, like ivy, can. However, it still produces flowers even if it is sprawling rather than climbing.

To encourage flower and fruit production rather than excess foliage growth, try restricting the development of the spreading root suckers. Growing it in a container is a good option.

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:

1. In the spring, select a 6-inch cutting from a young shoot with leaf buds (you can also take woody cuttings in early summer).
2. Remove any leaves at the base of the cutting.
3. Put the base of the cutting into a well-drained potting mix at a depth of around 1 inch.
4. Moisten the potting mix and cover the pot with plastic with a couple of air holes.
5. Keep the plant warm, moist, and out of direct, intense sunlight.
6. It typically takes a few weeks for the cutting to start taking root.
7. Once the roots have adequately taken hold, you can transplant it to its outdoor location.

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.

1. Remove any leaves and nodes before pushing a vine tip into the soil for a smooth finish. Foliage buried in the soil can lead to bacterial problems.
2. Make a dip in the soil, place the tip into this space, and then cover it with soil.
3. You might need to weigh down the tip with a small rock or garden anchor pin to stop it from popping up and losing contact with the soil.
4. When the tip is well-rooted (it should stay in the ground when you tug on it), it should create another plant in the same place. Alternatively, you can dig it up and detach it from the original plant to transplant it to a different location.

How to Grow Purple Passionflowers From Seed

You can propagate purple passionflowers from seed, although it is a little more tricky than 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:

1. If you are using seeds from an existing plant, these can be taken from the berries when soft, shriveled, and yellow.
2. Mature seeds are brown, and the best chance of germination occurs when they are sown immediately after picking.
3. Clean and soak the seeds in warm water for 12 to 24 hours. Floating seeds are not viable, and you should discard them.
4. Sow on the surface of a damp potting mix.
5. Put the pot in a plastic bag to seal in the moisture.
6. Keep the seeds out of direct sunlight while waiting for leaves to appear. Grow lights and a consistently warm temperature during this time can help increase the chance of successful germination.
7. When the seedlings are large enough to handle, you can pick them out and put them into individual pots.
8. Seedlings benefit from being kept in a warm environment for the first winter before planting them after the last frost in late spring or early summer.
9. Harden off the plant for around two weeks before transplanting to the permanent position.
10. The seeds can be sown outdoors if temperatures stay above 55 degrees Fahrenheit.

Potting and Repotting Purple Passionflowers

You can successfully grow passionflowers in containers, where they will offer you the convenience of being able to move them to a sunnier site or even bringing them indoors for the winter. Additionally, growing in pots prevents passionflowers from spreading uncontrollably.

To successfully pot your passionflower, use a potting soil rich in nutrients, and make sure the pot (of any material) has several large drainage holes at its base. Keep the soil moist, but don't allow the roots to sit in water. Plants grown in containers will need more regular feedings since they are watered more frequently and nutrients typically rinse out as the soil drains.

Because purple passionflowers are such heavy feeders, even with fertilizers, your plant will exhaust the nutrients in the pot after a few years.

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.

Overwintering

You can overwinter your plant outdoors down to USDA zone 5 or 6 if you provide ample winter protection. If it's in a container, move it up against a building as a windbreak. Also, wrap the container in a blanket or burlap. If it's in the ground, add two to three inches of wood or leaf mulch around the plant and leave space around the main vining stem. Withhold fertilizer for the two months leading up to the cold season.

Bring the plant inside if it's too cold for your plant outdoors. Allow the plant to enter dormancy by placing it in a basement or garage that doesn't drop below freezing. Do not expose it to the sun. Only water the plant once a month.

You can also treat the plant as a houseplant, placing it in a window to get at least six hours of sunlight, keeping it at a warm ambient temperature, and feeding it as normal. However, this is a vining plant that needs a trellis. To keep it manageable, trim it and give it a climbing structure. Water it less frequently than in summer, perhaps once a week or every 14 days.

Common Pests & Plant Diseases

One of the appeals of the purple passionflower is its moderate resistance to deer, pests, and diseases. However, pests such as scale insects, spiders mites, and whiteflies might be problematic 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

Loose, hanging vines are more likely to produce blooms, so don't try to train your plant too formally. Their striking, fragrant flowers are attractive to butterflies and other pollinators.

Bloom Months

Purple passionflowers typically bloom in June and July, sometimes August. The pollinated blooms develop fruits in the fall.

How Long Does Purple Passionflower Bloom?

The flowers only typically bloom for a day throughout the summer and early fall.

What Do Purple Passionflowers Look and Smell Like?

The purple-pinkish flowers look exotic, with a wavy fringe of filaments. The middle of the bloom looks like a little raised platform, with a tiny yellow pollen sac suspended over it. The sweet, fragrant summer blooms are around 1 to 3 inches wide and typically only bloom for a day.

How to Encourage More Blooms

Because they are heavy feeders, you might be disappointed by their bloom yield if you don't get the nutrient levels right. If your passionflower plants are not making plentiful flowers, your fertilizer mix could have too much nitrogen. Nitrogen focuses on leaf production. Consider adding more phosphorus to the fertilizer mix.

Caring for Purple Passionflower After It Blooms

Do not prune purple passionflower after it blooms if you wish to have fruits. It's best to wait to prune until the plant has fruited and the growing season ends, usually by late fall.

Deadheading Purple Passionflower

Purple passionflowers do not need to be deadheaded. The flowers drop naturally after they fade.

Common Problems With Purple Passionflower

Purple passionflower is a relatively easy plant to grow. It's native to the United States, so it is not an invasive species; however, it can grow aggressively where conditions are right.

Yellowing Foliage

Passionflower plants may turn yellow or wilt if they are underwatered, get cold, or lack nutrients. Test the soil to confirm the balance of nutrients.

Plant Is Not Flowering

Young vines do not produce flowers until maturity, which can take up to a year. Too much fertilizer, particularly nitrogen, can discourage bloom growth for the sake of more prolific leaves. Reduce fertilizer rates once the plant has grown to maturity.

Plant Is Not Fruiting

If the primary pollinators, honey and carpenter bees, are absent, hand-pollination is needed to transfer pollen between flowers. Other issues leading to poor pollination rates include too much rain, high humidity, and too high or too low temperature.