Mountain View Experimental Gardens Welcome to The Wonderful World of Penstemons
The Wonderful World of Penstemons
Penstemons are easy-to-grow species for western gardens. Most will grow easily on dry, gravelly or sandy soils with low moisture content and low fertility. The best species for these conditions are those with narrow, gray-green leaves. Put them in full sun.
Penstemons with large, green leaves will appreciate a good, loamy soil that will retain moisture without being boggy and some shade.
There are around 275 species of Penstemons in the world - most of which are native to western North America. In addition, many cultivars (cultivated varieties) are available for sale as plants from garden centers and nurseries.
Most Penstemons are easy to grow from seed, although you may have to stratify the seeds (give them a cold, moist treatment to simulate winter) before attempting to germinate them indoors under fluorescent lights.
If you want to sow them where they are to grow, scatter the seeds in fall. Don't bury the seeds. You can protect them from birds by lightly sprinkling a thin layer of sand over the prepared area after you have sown the seeds.
If you would rather have more control over germination and have room to place one or two 11-inch by 22-inch standard, black plastic germinating trays filled with your choice of individual cells, first sow the Penstemon seeds in moist seed-starting mix (such as Jiffy Mix) and either put the containers outside under snow over the winter or slip the containers into a clear, plastic bag (Zip-loc or Baggie), seal the bag and place in the refrigerator (not the freezer) for several weeks.
In spring (outdoor stratification) or after the chilling period (refrigerator stratification), remove the plastic bags and place a sheet of kitchen plastic wrap over the containers. Then put the containers (in the trays) under a 40-watt, double-bulb, cool-white fluorescent fixture (an inexpensive "shop light" will work perfectly). Run the lights during the day (not at night) for 16 hours, then turn them off for 8 hours. Check the trays every day for signs of germination.
As the little plants begin to rise above the surface of the seed-starting mix, remove the plastic wrap and raise the lights just enough to allow the leaves to clear the light bulbs.
Check the seedlings every day, turning the trays and cells to be sure that the little plants receive even light and do not begin to stretch towards the bulbs. Also make sure the seed-starting mix doesn't get bone dry but be careful not to overwater it. Penstemons will do better in drier soil than in wetter soils.
Give the seedlings a weekly feeding of liquid fertilizer (such as Miracle-Gro) at 25% of the recommended amount for houseplants. When the seedlings have put on 3 to 4 pairs of true leaves, separate them carefully and replant each seedling in fresh seed-starting mix in an individual container and return the plants to the lights.
When the weather warms above freezing outdoors, gradually accustom the seedlings still in their containers to outdoor conditions, bringing them in at night if frost is in the forecast.
By mid-spring, your seedlings should be large enough and strong encough to go out in a prepared bed in your garden. After you plant them, be sure to keep themn well watered until they are established.
I hope you will enjoy the many colorful Penstemons in this album. You will find more Penstemons in the respective alphabetical albums entitled "Rocky Mountain Wildflowers", "Desert Wildflowers" and "Arizona and New Mexico Upland Wildflowers".
We have tried our best to correctly identify these Penstemons. However, if you find incorrect botanical names or can identify the "sp." Penstemons, please e-mail