Penstemon normally blooms during the summer; it is a popular flowering plant that comes out in different colors when planted. As it develops, it will not produce many flowers because its stems have become woodier.

But there are also some ways you can make these old penstemons develop flowers during the summer. One is to simply cut out the parts that are old and weary. In this post, I am going to be showing you how you can properly prune penstemons in order for them to produce many shoots during the summer.

Step 1 of 3

Cutting them Back during the Growing Season

1. Remove the deadhead in order to encourage a second round of shots

Wait until you notice the penstemon’s flowers and blooms wither. Then get a pair of garden knives and cut off the deadheads that are on the flowers.

2. Cut back the stem of the plants that look rough around the edges

Although you can leave the penstemon to grow naturally, the stems may grow out sporadically, and that may not give the flower a good look. Get a pair of garden shears and cut it from about one-third up to the tip of the stem.

When you see stems that are longer, cut them until they look even; also, be careful when trimming the stem; trimming more than one-third of the stem can hinder the blooming of the plant.

3. Prune part of the withered stem during winter

Immediately you notice the flowers of the penstemon withering and turning brown; you are free to prune it to an extent. Use a pair of pruning shears to work your way down to the stem from the tip, cut back most of the stems until the brownishness is less visible.

Only cut about one-third of the stem and leave the rest for the summer. If you cut more than one-third of it, you might cause the penstemon to die during the winter.

Step 2 of 3

Pruning Back Old and Weak Growth

1. Trim back the penstemon after the last frost in spring

It is advisable to leave the remaining growth on your penstemon during the winter. This is necessary to protect the plants from the harsh weather and increase the possibility of them surviving.

There will be no risk of frost when the weather starts warming up. This will be a perfect time to cut back the stem. Ensure to check your last estimated frost date. If you cut the plant anytime earlier than the date, it may hinder the growth of the plant in the next season.

2. Locate weeds around the penstemon and get rid of them

Check for any weed or any other plant growing within 18inches from the penstemon; get rid of them. In order to prevent these weeds from growing near the penstemon, you can lay a weed barrier around the area where the penstemon grows.

3. Trim dead growths down to the base

Check the stem of the penstemon to see if they are fresh green shoots growing from them. If you see any plant that doesn’t have a single shoot, use the pruning shear to carefully cut them out.

Also, cut out stems that are cracked and damaged. This is necessary for other stems to produce healthy shoots.

Step 3 of 3

Using Cutouts for Propagation

1. Cut out 10cm of the non-flowering plant

While the penstemon is growing during the summer, you can easily be able to take out your cuttings without harming the plant. Find a few stems that do not have any flowering growing in them. Cut them out from the point where there are fewer leaves.

2. Trim the end of the cutting

Locate the end of your cutting and pluck out the leaves that you see there; it will help in exposing the base of the stem and increase its overall growth.

Alternatively, you can trim off a third of the leaves from the stem. This will help in reducing the moisture when replanting it.

3. Place the ends of the cut into a bowl of rooting hormone.

Purchase a pack of rooting hormones; this will help in stimulating the plant’s growth and eliminate fungus from the roots.

Pour it into a bowl; place the ends of the cuttings into the bowl that contains the rooting hormone. Use the same process on all your cuttings. It will greatly increase the growth rate of the plant.

After you are done with the bowl of rooting hormone, it is advisable to throw it away. Using it again may increase the risk of spreading plant disease.

4. Prepare a pot of perlite and compost

Get a planting pot; fill it up with compost mixed with perlite. Ensure that the mixture completely covers the pot.

5. Place the cuttings into the pot

Place the stem of your cutting around the edges of your pot, and then push it into the mixture until it is firm.

6. Pour water into the pot until the mix is damp.

Get a new and clean watering can and pour water into it. Pour the water gently into the pot that contains the compost and perlite.

Continue pouring the water into the pot. When you are sure that the mixture is damp, you can stop adding water to it.

7. Place the pot into a propagator or use a plastic bag on it

Get four sticks or bamboo poles. Ensure that the sticks or bamboo poles are taller than the cutting you have planted in the mix. Place those sticks on the four corners of the pot.

Use the plastic bag to completely cover the stick and the plant. It will help in trapping the moisture and increase the plant’s growth. You can also place the pot into a propagator, but you have to ensure it is one that is not heated.

8. Store the pot in a place without risk of frost

Ensure that the place you are storing the plant is free from frost. If you stay in an environment with freezing winters, take the plant inside and allow it to grow there. You can also decide to place them in a greenhouse.

My Wrapping up

Penstemon can be really beautiful when blooming in the summer. But to help them grow healthier and prevent them from dying, you can follow the tips that have been mentioned in this post. Thank you for reading this article. If you have any questions, please leave your comment below, and I’ll be happy to write back to you.