The unusual-looking flowers bloom from midsummer to early fall but only last about one day. Passionflowers will die back in the winter. These plants are native to North America, growing from Delaware west to Missouri and south to Texas and Florida, and also grow in Central and South America. A passionflower has a wide, flat petal base with five or 10 petals in a flat or reflex circle. Passionflowers are rapid growers, coming back every year. They are best planted in spring or early fall while it’s still warm. The plant’s toxicity varies by type, so check which one you are growing if you have small children or pets. Where they are hardy, passionflowers are usually trained on a trellis, fence, or other vertical structures. In regions where they are not hardy, passionflower plants are often grown in pots and moved indoors for the winter. Typically, they should be grown in full sun to partial shade, in average, but well-drained soil. A sheltered location, such as against a garden wall, is recommended for many species, which can be damaged by major winds or harsh weather.

Light

To keep your passionflower vines healthy and blooming, plant them in full sun to partial shade. Plants appreciate some afternoon shade in extremely hot climates. Passionflowers generally need at least four to six full hours of sunlight a day (or more in cooler climates). If you bring potted specimens indoors for the winter, give them bright, indirect light and keep them away from drafts.

Planting and Soil

The soil in which you plant your vines should be well-draining but rich and moist. Soil pH isn’t important and can be in the neutral to the acidic range, anywhere from about 6.1 to 7.5. Adding compost to the planting hole will help provide nutrients, and mulching around the plant’s base will assist in retaining moisture without having the plant become waterlogged. Passionflower is best planted in the spring or fall. It prefers a sheltered area, like a wall. Typically, some support is needed for passionflower vines to grow, such as a trellis, a structure, or another plant. You can train it to go up a pergola or other structure, but it only needs a little guidance and doesn’t require tying since it has self-clinging tendrils.

Water

Passionflowers should be given a deep watering immediately after planting. Beyond that, they typically thrive with one or two waterings per week throughout their growing season. Make sure to provide about 1 inch to 1.5 inches of water every week.

Temperature and Humidity

Passionflower plants love warm weather and may need winter protection in cooler regions. To prevent your plant from dieback, bring it indoors as temperatures drop. Plant them in an area that’s protected from wind, as a strong wind can damage stems and burn leaves. In addition, they do best in areas with moderate to high humidity.

Fertilizer

Passionflower vines are heavy feeders and will benefit from a regular light application of balanced, general-purpose fertilizer with equal proportions of nitrogen, phosphorus, and potassium. Fertilize the plant before new growth emerges in early spring, and then repeat every four to six weeks until early autumn. For the amount to use, follow product label instructions.

How to Grow Passionflower Indoors

Passionflower grows best outdoors, but if you live in an area with freezing winters in a USDA zone lower than a mild 6, bring your passionflower vine indoors as the threat of frost approaches. Grow it in a south-facing room, sunroom, or greenhouse. When grown inside, it will not grow as vigorously nor produce fruits. Dig up your passionflower with its rootball intact and repot it in a container with ample drainage holes in moistened, enriched potting soil. If possible, move your plant back outdoors in the spring once the threat of frost is over.

Types of Passionflowers

There are hundreds of varieties of passionflower, though they mostly differ in color and appearance, not care. Some of the most popular cultivars for landscaping and gardening include:

Passiflora caerulea: blue passionflowerPassiflora coccinea: red passionflowerPassiflora incarnata: purple passionflowerPassiflora alata : “Ruby Star,’ fragrant granadilla

Pruning Passionflower

Passionflowers are low maintenance during their growing season and do not need to be deadheaded. Pruning is done more to keep the size of the passionflower vine in check, remove deadwood, and encourage fuller growth. Pruning can be done in late winter or early spring—in cooler climates, the vines may die back to the ground anyway. These plants flower on new growth, so make sure to prune them before growth begins each spring in order to preserve the season’s blooms.

Propagating Passionflower

In addition to growing passionflower from seed, the plant can be propagated using methods such as taking softwood stem cuttings and tip layering (which works like air layering, but it’s done in the ground). Softwood cuttings are used to propagate when you want to start a new passionflower plant in another part of your yard or garden without having to wait for seeds. Layering is an ideal method to propagate passionflower right in the garden without having to do any passionflower vine cuttings from the mother plant, and it requires only a tiny bit of dirty work in the late summer or early fall. Here’s how to propagate passionflower using these two methods.

Propagate With Softwood Cuttings

Propagate by Tip Layering

How to Grow Passionflower From Seed

Most varieties of passionflower can be purchased as seedling plants. They can also be propagated from seed. Follow these steps to grow passionflower from seed.

Potting and Repotting Passionflower

Many gardeners prefer to grow their passionflowers in containers, where they will grow quite happily and 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.

Overwintering

If you are bringing a container-bound passionflower plant indoors for winter, trim the stems down to 1 or 2 feet high before moving it. It will probably go semi-dormant and look less than ideal, but it should perk up again in the spring.

Common Pests and Plant Diseases

The warmer and more humid the climate, the more pests there may be to attack your passionflower plants, including scale, spider mites, and whiteflies. You can attempt to control any infestations with an insecticide. Leaf spot is another potential issue and is generally caused by a fungal disease. To rid your plant of it, remove affected leaves to slow the spread and treat the plant with a fungicide if necessary. Root rot is also common in soils that do not drain well.

Common Problems With Passionflower

The passionflower is a relatively carefree plant to grow, but it may turn yellow for a variety of reasons. Potted passionflower plants may turn yellow or wilt if they are being underwatered or feel too cold. Passionflower plants in the ground may have yellowing leaves because there’s a problem with the soil’s nutrients. You can have the soil tested so it can be properly amended. The soil may be too rich in boron, or the soil may lack the essential ones the plant needs to thrive. Some nutrients that may be lacking include:

IronMagnesiumManganeseMolybdenumNitrogenPotassiumSulfurZinc