Penstemon (Penstemon spectabilis) is endemic to North and Central America, where it thrives in hot, sunny climates. This drought-tolerant plant’s tubular blooms in purple, red, pink, blue, and white last for approximately a month in late spring and early summer, when it can be used in flower beds, borders, or rock gardens. Depending on the cultivar, penstemon can reach a height of 12–36 inches and thrives in USDA plant hardiness zones 3–10. Penstemon cuttings taken in the late summer can be used to propagate the plant.
Prepare a Pot of Rooting Medium
Potting mediums that are loose and well-draining, such as perlite, vermiculite, coarse sand, or a mix of half sand and half perlite or peat moss should be used. After fully moistening the potting media, allow it to drain for a few minutes so that it isn’t dripping wet. The roots of the cuttings are more susceptible to decay when they are placed in a potting medium that is too damp or poorly draining.
Prepare the Pentstemon Cuttings
A sharp knife or pruners are recommended by the Royal Horticultural Society for cutting 3- to 5-inch stems from the tops of a healthy, fully established penstemon plant. Just below a leaf or bud, cut the stems. Do not be afraid to take more cuttings than necessary; you never know if some of them will take root. The stem’s bottom half should have no more than three leaves; the stem’s top half should have four or more.
Apply Rooting Hormone to the Cuttings
Use a pencil or similar tool to make planting holes in the damp potting material. Cuttings should be dipped in powdered rooting hormone before planting, according to the American Pentstemon Society. The stems should be placed in the holes and covered with the potting medium so that they stand upright. Several stems can be planted in the same pot, but they should not contact each other.
Give the Cutting Bright Indirect Sunlight
Secure the bag to the pot’s base with a rubber band by placing a clear plastic bag over it. In order to avoid scorching the cuttings, the pot should be placed in bright, indirect sunlight. Between 65 and 75 degrees Fahrenheit, the pentstemon cuttings will root best, but not lower than 55 degrees Fahrenheit overnight.
Provide Moisture and Air Circulation
Every day, open the bag for a few minutes to let the air to circulate through it. Alternatively, you can puncture the bag with a needle. This is particularly critical if you find water beads inside the bag. For several weeks at a time, the plastic creates a humid greenhouse environment. Every day, check the cuttings and sprinkle the potting material to keep them moist.
Check for Rooting
Lift the cuttings from the potting material using a table knife after two to three weeks to see how the penstemon is doing. A 3- to 4-inch pot filled with ordinary commercial potting soil should be used for each cutting if the roots are half an inch long. It’s best to start over with new stems if the roots are less than half an inch long.
Acclimate in Lower Light
In order to help the cuttings adapt, keep the little pots in low light for a week or so before moving them outside. Pots should be placed in strong light and watered on a regular basis after that time. When cuttings begin to droop, place them in a plastic bag and keep them there for about a week.
Plant the Pentstemons in the Garden
Penstemons should be planted the following spring when all danger of frost has passed.
Things You Will Need
- The medium used to grow plants.
- With a hole on the bottom for water drainage
- Pruning shears or a knife
- Rooting hormone in powder form
- Plastic bag with a transparent exterior
- A rubber band is used here.
- Table knife
- Pots of 3 to 4 inches
- Commercially available potting soil
How To Propagate Penstemon For Beginners
Rooting from cuttings
There is a good probability that you want to learn how to root cuttings from an existing penstemon cultivar. Propagation via cuttings is more dependable than from seeds if you want the same traits as the original plant. And the best part about penstemon is that you may take softwood cuttings at any time of the year.
Experienced gardeners, on the other hand, advise taking 5-inch cuttings in the final weeks of summer or the first weeks of fall. When propagating penstemon from cuttings, it’s important that the cuttings have no flowers, same like when propagating vinca. After removing the lower leaves, trim the top and side leaves of your cutting as well to avoid moisture loss.
Rooting hormone and a compost-perlite mixture should be dipped into your cuttings to stimulate growth. Penstemon cuttings can be planted anywhere. Cuttings can thrive in a greenhouse, according to the North Carolina State Extension, which advises it.
Modular trays or a container can be used to host five cuttings of penstemon. Once your plants have taken root, you can move them to a new location. In order to ensure the long-term viability of your rooted cuttings, you can place them in a greenhouse.
Rooting from seeds
If you are not particular with getting your parent plant’s clones, you can propagate penstemons from seeds. Plants should be started indoors to prevent damage from sudden changes in weather or temperature. Still, remember to sow in early spring and then plant the penstemons outside come early summer.
For penstemon seed propagation, don’t worry too much about getting clones of your parent plant. Plants should be started indoors to prevent damage from temperature fluctuations. It’s still a good idea to start the penstemon seeds in the spring and then transplant them outside in early summer.
Seed-propagation of penstemon is also hampered by the fact that most species require a long time of wet stratification. Using northern penstemons, failure to follow these instructions will result in poor seed germination. Your best bet for meeting the unique needs of penstemon seedlings would be to construct a greenhouse.
Rooting from divisions
Penstemon, like hellebores, can be multiplied through division. If you want to guarantee the exact qualities of your hybrids and specific species, this is a beneficial procedure. If you have an established plant that you want to replicate, you can do so by dividing it.
Division is an excellent option if you have a plant that has become woody over time. Once the plant has been gently dug up, loosen the soil around it so that it can be easily divided. The crown of the Penstemon digitalis can be divided into numerous rosettes, making it one of the easiest penstemons to divide.
The timing of planting the divisions depends on the climate where you live. As a result, early spring division is highly suggested to allow the plants to recover before the summer heat arrives. Alternatively, you can divide the plant after it has bloomed or when the summer is over.
Prior to transplanting, make sure that your plants have time to recover from the severe conditions. It’s best to keep each part in a pot of moist soil until replanting them in the ground.
Rooting from layering
Last but not least, layering is a method of growing penstemon. Because you just need to clip the stems that have already propagated and rooted along the ground, this method is much simpler than traditional dividing. There’s no need to disturb the parent plot, and the propagation parts are still available.
You can either plant the parts right away or wait until the roots have developed to match the size of the section, similar to rooting by division. Remove some of the penstemon leaves and mound some soil around the stem to encourage more roots to grow. You can even sprinkle it with rooting powder or pin the stem with a bent wire so that it can root more effectively.
Beardtongue (penstemon) or beardtongue is a lovely plant with a wide variety of options. If you want to grow penstemon successfully, you’ll need to learn how to propagate it. Depending on your variety, you have a choice of cuttings, seeds, division, or layering.
Some penstemons have unique germination needs, thus seeds may be the most difficult way. The remaining three, on the other hand, are better if you want to be sure your parent plant copy is guaranteed. The use of a greenhouse, on the other hand, allows gardeners to regulate the perfect conditions for the growth of penstemons, making propagation more likely to succeed.