Some may not appreciate the weedy appearance of biennial Gaura, but this flower has its place in building prairies. This biennial blooms late in the season, providing nectar for pollinators. It self-seeds easily due to its slender, bending stems that bob in the wind.
I. Appearance and Characteristics
Oenothera gaura, formerly known as Gaura biennis, the biennial gaura or biennial beeblossom, is a North American flowering plant.
Biennial gaura naturally occurs throughout eastern and central North America, and extends as far north as Quebec, Canada. Some of the states in the U.S. it can be found in include: Connecticut, Delaware, Georgia, Illinois, Kentucky, Massachusetts, North Carolina, South Carolina, New York, Texas, and Virginia.
Individuals of this species are tall and weedy, with white to light pink flowers during blooming season, and leaves that turn a red color when mature. The flimsy makeup of the plant allows it to sway in the wind, which makes seed dispersal easier. A few hair-covered stems exit from the top of the plant where the flowers grow, which is the easiest way to tell that the species is the biennial beeblossom. Flowers usually have 4 petals, 8 stamens, and 1 pistil. It starts as a small plant, but grows anywhere from 0.9–1.8 m (3–6 feet) during its second year.
The flowers are attractive white to light pink color. They have 4 petals, 8 stamens, and 1 pistil, which are mostly pollinated by bees and other insects. The fruits are capsules, ribbed or ridged, and are occasionally woody. It produces small seeds that are easily dispersed by wind and other methods.
Oenothera gaura is a biennial plant, meaning it completes its life cycle over the course of two growing seasons, in which it will usually reach full maturity towards the end of the second growing season. It lives mostly in prairies throughout North America, and in dry, rocky places and deserts. It prefers sunny, dry areas, but has the capability of adapting to a wide range of habitats because of its ability to grow deep roots. In order to survive wet winters, it needs a dry spot in light soil.
II. How to Grow and Care
Biennial Gaura is generally considered easy to care for, thriving in well-draining soil and full sun exposure. Key special care points include deadheading spent blooms to encourage further flowering and providing moderate watering, as biennial Gaura is drought-tolerant once established. Regular trimming can maintain a desired shape and promote healthy growth.
Sunlight
Biennial Gaura enjoys a lot of light (at least 8 hours a day) and should be cultivated under full sun, but it can also withstand partial shade. Well-ventilated, sunny areas in the courtyard are optimal for planting biennial Gaura. If it is too shaded, the plant will grow poorly and produce fewer flowers. If cultivated indoors, it is important to pick the sunniest spot for your plant.
Temperature
Biennial Gaura is very tolerant of cold and can withstand temperatures down to -20 ℃. Its optimal temperature for growth is 18 to 24 ℃. Temperatures above 27 ℃ are not favorable, as biennial Gaura is not well-adapted to withstand prolonged, intense heat.
Biennial Gaura prefers a dry-to-medium humid environment and is tolerant of drought. The soil should not be too dry during cultivation, especially if the aim is to encourage the plant to grow vigorously and produce numerous flowers. Biennial Gaura doesn’t tolerate waterlogging, so the well-draining substrate is very important.
Watering
Biennial Gaura thrives in well-drained soil, indicative of its origins where periodic droughts are common. This species exhibits a preference for moderate moisture levels and has adapted to survive brief dry spells. Regular watering every week will maintain its optimal hydration balance. As an herbaceous plant, biennial Gaura is often cultivated outdoors where it can benefit from natural rainfall patterns, aligning with its water needs during the active growing season.
Soil
Biennial Gaura can grow on a variety of different soil types, but it prefers light, loamy, sandy soil with medium moisture and good drainage. If you plant it in clay, improve the nutrient content and drainage of the soil by adding sand, leaf mold, some organic fertilizer, and crushed coal residue. The soil should be neutral, slightly acidic, or slightly basic (pH 5.5-7.5).
Fertilizing
For biennial Gaura, use a high phosphorus fertilizer to encourage robust flowering. Fertilize bi-weekly during the growing season, tapering off as dormancy approaches. Apply approximately 1/4 strength of the recommended dose to prevent nutrient burn. Benefits include enhanced vigor and bloom quality. Adjust quantities for potted biennial Gaura or if growth appears lackluster, and always water soil before application to protect roots. This schedule optimizes biennial Gaura’s floral display and overall health.
Pruning
Biennial Gaura should be cut back to the ground after the leaves dry in late fall. This promotes vigorous growth and abundant new foliage in the spring. Cutting back can also be performed after the winter, during the first days of spring. Proper pruning reduces the probability of pests and diseases in the following year.
Propagation
Biennial Gaura is a herbaceous plant known for its tall spikes of pink and white flowers that add charm to gardens. To propagate biennial Gaura, the viable approach is sowing seeds, which should be done in well-drained soil. Seedlings require careful handling, with a gentle touch to not disturb the delicate root system. A consistent watering routine, ensuring the soil remains moist but not waterlogged, can foster healthy growth. For successful cultivation, guarding against overwatering and providing ample sunlight is crucial, as these conditions mimic biennial Gaura’s natural habitat preferences.
Transplanting
The prime time to transplant biennial Gaura is during the budding vitality of mid to late spring, ensuring a mild, nurturing environment. Select a site with well-draining soil and partial sun. Carefully consider local conditions for optimum growth when transplanting.