Evening Primrose Plant Profile

Aggressive Spreader Not Suitable for All Gardens

Evening primrose blooming with yellow flowers.

Chushkin / Getty Images

In This Article

Common evening primrose does have its admirers, but at least as many people take the opposing position on it and term it a "weed." You will have to come to your own conclusion on this plant after firmly establishing what type of landscape design you seek and studying the plant's features. After comparing evening primrose with other plants competing for a space in your yard, you may well conclude that it is not worth growing.

Botanical Name Oenothera biennis
Common Name Evening primrose, common evening primrose, tree primrose, evening star, fever plant, cure-all, night willow-herb, wild four o'clock
Plant Type Biennial
Mature Size As much as 7 feet tall (but usually about 3 feet tall) with a width just a fraction of that
Sun Exposure Full sun
Soil Type Well-drained, with average moisture content and average fertility
Soil pH Neutral to slightly acidic or slightly alkaline
Bloom Time June through September
Flower Color Yellow
Hardiness Zones 4 to 9
Native Area North America

How to Grow Evening Primrose

A bigger question to start with is whether you should grow common evening primrose at all. The flowers are not particularly big and come out when most people are indoors (thus the name of "evening" primrose), the foliage is ratty-looking, and the plant will spread where you do not want it to go. Many gardeners consider it a weed.

If none of those facts deter you, then you are in luck, because the brownest of brown thumbs can grow this biennial. And it is perfect for moon gardens because its bright yellow flowers open up as the sun starts to set and remain open only till morning (although they may stay open longer on cloudy days). Various beetles eat the leaves of evening primrose, but they will not kill the plant and you probably will not even notice them under cover of darkness while enjoying a moon garden.

Evening primrose is grown from seed. Although you can buy the seeds online, you probably will not have to: This plant is so widespread that you should be able to collect seeds for it from wild plants growing along the roadside.

Once you get the seed, plant it either in autumn or in early spring. Pick a location in full sun with good drainage and where the soil has been previously cultivated. Sow the seed on top of the ground. After germination, thin the seedlings so that they are one foot apart.

In the first year, evening primrose will not flower but will simply produce a leafy rosette at ground level. The leaves of this basal rosette are 4 to 8 inches long and lance-shaped. A white vein runs along the middle of each leaf.

In the second year, the tall, stiff, purple-tinged flower stem shoots up out of this base. About midway up this flower stem, secondary branching occurs. The leaves become progressively smaller the farther you go up the flower stem.

The four-petaled blooms that begin coming out at the start of summer are about one inch wide. They are pollinated by night-flying insects. The seeds that form thereafter are eaten by wild birds.

Light

Evening primrose is a very easy plant to grow, but a major requirement for growing it is full sun.

Soil

Another major requirement for growing evening primrose is good drainage.

Water

Evening primrose does best with adequate irrigation. Still, the plant is quite drought-tolerant.

Fertilizer

Although evening primrose will perform better in soil of average fertility, performance can be heightened by growing it in soil that has been amended.

Uses for Evening Primrose

Some of the common names ("cure-all," "fever plant") for evening primrose allude to its medicinal properties. It has been used traditionally to treat a number of ailments, including asthma, coughs, and skin diseases. Its long taproot is edible if you dig it at the end of the plant's first year and boil it twice. The flowers are also edible, whether raw or cooked; some use them in salads.

However, as with all wild plants, it is best to seek expert advice before experimenting. Some people can eat a plant and be fine, while others may try the same plant and have an adverse reaction to it. For example, in the case of eating evening primrose, some have reported getting an irritated throat from it.

In the landscape, evening primrose is not attractive enough to be used extensively. It is a must-have for moon gardens, and those keen on growing native plants in North America may also be interested in it. Otherwise, reserve it for cottage gardens planted on a budget and for wildflower gardens.