How to Plant, Grow, and Care for Rocky Mountain Bee

If you want to add a low-maintenance annual flowering plant to your garden, look no further than the Rocky Mountain bee plant! These plants originated in western North America and southern British Columbia. They can thrive when grown inside their native range with little to no human intervention.

Native Americans used these plants as food, but today, gardeners admire them as pollinator plants that attract butterflies, hummingbirds, and native bees. They also support local wildlife since the seeds are an important food source for doves and other small birds.

These native plants grow tall, sometimes reaching up to six feet! Their tall, lanky stems sway in the breeze, topped with beautiful pink-purple flowers. Because of their height, it’s best to pick a location in your garden where they won’t shade out smaller plants. Bee annuals (Cleomella serrulata or Cleome serrulata) can help create visual interest in your pollinator garden when grown behind other smaller flowering plants.

They readily self-seed year after year, which leads to them popping up in patches in open woods, prairies, and even ditches alongside roads (they seem to prefer disturbed ground). Cleome serrulata can survive in poor soil conditions and tolerates drought, making it a great choice for the water-wise garden!

Once established, it needs little water other than what it receives from natural rainfall. In times of extended drought, it may need some additional moisture. In the past, growers have also cultivated it for use as a dye.

Native Area

The native area covers the western and central regions of the United States, as well as parts of northern Mexico and southern Canada. The annual typically grows in dry, open areas such as plains, deserts, and foothills, often in sandy or gravelly soils.

Characteristics

This annual plant usually has pink flowers, but they can be reddish purple as well. The flowers have four petals and six long stamens. Plants have an erect growing habit with a single tall main stem and several side shoots that branch off.

Some have described the flowers as smelling “clammy” or “briny,” similar to capers. This makes sense since Rocky Mountain bee plants are related to the caper plant (the Cleomaceae family belongs to the same order, Brassicales). The smell is how the flowers attract pollinators.

Also, despite some of its names, Cleome serrulata is not considered invasive or noxious. In fact, it is a wonderful native plant that attracts all types of pollinators, such as butterflies and bees, and small birds like hummingbirds.

The spirally arranged leaves are trifoliate with three slender leaflets, and identifying the young leaves is the best way to recognize seedlings before they’ve flowered. Bee annuals put down a very deep taproot, sometimes reaching up to a foot deep.

Once you begin growing a Rocky Mountain bee plant, you’re sure to soon have an endless supply. It is an annual that produces fruit that develops into seed pods at the end of the growing season. These pods resemble small beans, and each contains several seeds. This seed comes in handy since the bee plant does not survive any level of frost and will die in the winter. You’ll need to sow each year to continue your bee plant patch, but the seeds are very easy to collect.

Collectors first gathered this annual in 1804 during the Lewis and Clark expedition. At that time, they noted that Native Americans were cultivating it. They traditionally used it as a food source, a medicinal treatment, and a source of dye for coloring fabric and pottery.

How to Grow

Cleome serrulata (and many others in the Cleomaceae family) thrives on borderline neglect, especially in its native range from southern British Columbia to northern New Mexico. This makes it a great choice for parkways or areas on your property where you wish to utilize the space to bring in more pollinators.

Light

It prefers full sun, although it will tolerate some light shade later in the day. Six to eight hours of sunlight daily will keep your bee plant happy. For this reason, in their natural habitat, the long stamens and slender leaflets of these native plants are commonly found growing in open woods, prairies, or on roadsides where they can receive full sun. 

Water

Rocky Mountain bee plants are perfectly suited to survival unassisted in their native range. For this reason, you may never need to water at all! It’s important to water early in the spring to aid seed germination, but once plants are established and growing in the summer, they can survive on very little.

Water them early in the day or in the afternoon after the heat of the day has passed. Water at the base of the plant to avoid wetting the foliage, especially in humid areas, to prevent powdery mildew.

Once the plants have gone to seed, watering is no longer necessary. Allow the seed pods to dry out on the plant and collect them for sowing next year.

Soil

Another benefit of adding Rocky Mountain bee plants to your garden is that they not only tolerate but prefer poor soil conditions. This species prefers light, sandy soil that drains well. Their taproots can penetrate the ground up to two feet deep, so you need not worry about amending the soil at your planting location.

Their three slender leaflets and flowers with four petals can be seen thriving in a roadside ditch, after all. The specific pH of the soil doesn’t matter as much as ensuring adequate drainage, as this species doesn’t do well in heavy, wet soils.

Temperature

These native flowers can survive a variety of conditions, and you can reliably grow them in USDA zones 2 to 10. They can even appear at elevations as high as 7,200 feet. As an annual, this plant does not tolerate frost and will die at the end of the growing season. It is, however, drought-tolerant and handles hot summer temperatures of 90°F (32°C) and above very well.

Fertilizing

Good news! You don’t need to fertilize your native Rocky Mountain bee plant at all! They are wonderfully low maintenance in all aspects. Not only do they require low water and prefer sandy soil, but they also don’t require any fertilizer.

Fertilizing your Rocky Mountain bee plant won’t hurt it, but it isn’t necessary. Plant it in a full sun location with well-draining soil, and you’ll enjoy beautiful pink flowers that attract honey bees and other beneficial insects all summer long!

Maintenance

You can prune the Rocky Mountain bee plant for a more compact appearance. However, the pink and purple flowers of this species are particularly stunning when left to grow wild! Like the rest of its family, it will grow erect and tall, sometimes up to six feet, with several stems branching off from the main stem.

Each stem will put out pink to reddish-purple flowers with six long stamens. If you choose to prune, cut back the side shoots and allow only one main stem to continue to grow. This will also reduce the overall number of pink flowers.

Propagation

The Rocky Mountain bee plant is an expert at producing its own seed. These are self-pollinators and create their own fruit. Once the bee plant has concluded flowering for the season, it will then focus its energy on producing what appear to be tiny bean pods. Each pod contains several seeds.

Leave the pods on the plant to dry at the end of summer and then collect the seed for next year. Remember that these seeds require stratification, so you will need to plant them in the fall for best results.

They also require sunlight for germination. Sprinkle them across your planting location and then cover them with a fine dusting of sand or light soil.

Common Problems

Aside from their lovely flower petals, yet another benefit of growing this plant is that no known pests or diseases trouble it! There are some growing problems to consider and some minor issues that may crop up, but otherwise, the Rocky Mountain bee plant is trouble-free.

Growing Problems

Most growing problems relate to the seeds. Rocky Mountain bee seed requires sunlight to germinate. For this reason, it is easy to accidentally bury the seeds too deep, preventing them from sprouting. When direct sowing the seed, cover it with a thin dusting of sandy soil or use a minimal layer of vermiculite. Since vermiculite reflects light, some of that light reaches downward into the soil, which aids germination.

This seed also requires stratification to properly germinate. The best way to achieve this is to sow your seed in the fall so that it can experience the natural cold, dormant period during winter. The plant itself will tell you when it’s time to plant the seed as the pods mature and dry out on the plant. Then you can crack them open and spread the seed.

If you’d like to plant them in the spring, they’ll need a faux dormant period, which you can duplicate by placing the seeds in a damp paper towel in the refrigerator for at least 30 days before planting.

Pests

There are no serious pests for the Rocky Mountain bee plant! That said, the plants are not completely immune to leaf-eating pests like leaf miners, aphids, and earwigs. However, these pests seem to prioritize other plants and leave bee plants alone.

Diseases

There are no severe diseases for the Rocky Mountain bee plant! That does not mean the plants are completely immune to diseases that affect the foliage, such as powdery mildew, or that the roots are immune to poor drainage conditions that cause root rot.

However, they are generally disease-resistant. It’s still a good idea not to wet the foliage while watering and to avoid planting in a location with poor drainage. These issues are more of a concern outside of its native range, particularly where it is humid, as this bee plant is accustomed to surviving in hot and arid conditions.

Frequently Asked Questions