Penstemon Barbatus

How To Grow Penstemon Barbatus

Native to western areas in the United States and commonly called the scarlet bugler, golden-beard penstemon and beard-lip penstemon, the penstemon barbatus is truly a stunning sight to add to anyone's landscaping.  These are quite reliable perennials that are relatively maintenance-free and resistant to most garden pests.

The foliage of the penstemon barbatus is a vibrant true green shade that is accented by the most gorgeous red tubular flowers you have seen.  These flowers grow all on one side of a slender, tall, upright stalk, resembling their snapdragon relatives.  Each individual tubular display can measure up to nearly two inches long.  They have two upper lobes that project forward and three lower lobes that are refluxed with a white-streaked base.  These are a favorite of both hummingbirds and butterflies however, they are not liked at all by deer so you don't have to worry about your flowers becoming breakfast.


The best time to plant penstemon seeds is in October, especially if you live in a warm climate area.  They bloom in the spring and once they are established you barely have to give them any attention at all.  These plants will happily reseed themselves or you can gather the seeds to use at a  later time or share them with someone else who could appreciate them.  Always be sure that you take the capsule off of the seed prior to planting.

Before planting your penstemon barbatus seeds, thoughtfully choose a location that offers full sun.  Remove any of the unwanted rocks and weeds from the area and loosen up the soil by using a rake.

Mix your seeds up with four parts of sand or soil and then evenly spread this mixture on your designated planting location.  Very gently rake the soil only in one direction so that you can cover the seeds back up with a very light amount.

Water the area everyday (unless it rains) until the plants have all sprouted and then you can reduce this to only watering every other day while the plants become established.  After your plants have made themselves at home, only water when they absolutely need it or else you can cause powdery mildew from soaking them too much.

Powdery Mildew

The number one problem seen with the penstemon barbatus is powdery mildew.  It is typically found from over watering, poor air circulation and not enough light.  If your plants have a problem with this, it is important to make sure that all debris is cleaned up in the area.  The powdered fungus is white or gray and it is typically found on the top surface of leaves.  The leaves will usually curl up, turn yellow and drop off and any new foliage that grows will be distorted.

Always make sure that your penstemon barbatus has adequate air circulation and light.  When watering, keep the water from sitting on the foliage by watering from below.  When applying fungicides, follow directions carefully.

Thinning And Pinching

These plants are quite active growers so there are times that you may need to trim them out out just a bit or else they will end up fighting for nutrients and lose their vigor.  Pruning also reduces the chance for disease by increasing air flow.  As the blooms fade, you can go ahead and deadhead them.  This will prevent them from seeding your entire garden.

Additionally, as these plants mature, a dense root mass may develop that will eventually result in a plant that has lost its luster.  If you divide the plant's root system, you can replant then somewhere else or give them away.  Pruning also rejuvenates the plant and helps to stimulate new growth.