Last Sunday was the Fall Equinox, so autumn is now official and we are heading into the year’s best time for installing trees, shrubs and herbaceous perennials.
When we plant in October, ideally just before the seasonal rains begin, our additions establish their roots during the fall and winter months and prepare for spring’s burst into leaf and blossom.
Many herbaceous perennials could be planted now. We will consider just three arbitrary but good selections:
English Lavender (Lavandula angustifolia). Several good varieties are available for this popular lavender. Small plants can be started now. In the spring, promote a compact mounded form by cutting the plant back to two inches above hard wood., and repeat in the spring of the second year. By the third spring, it will have reached mature size, or close to is, and produced a generous number of fragrant blossoms. With mature plants, a second pruning in late August will help in maintaining a good form. Replace lavender plants that have been allowed to develop a rangy form.
Salvia. Garden centers and mail-order nurseries offer about 100 species of salvia, with many selections and hybrids of most species. These “super shrubs” are native to many parts of the world, principally Central and South America, Central Asia and Mediterranean Basin, and Eastern Asia. California Blue Sage (Salvia clevelandii) is a California native that grows well in the Monterey Bay area; there are many other blossom colors, plant sizes and foliage forms available. The gardener could choose from the local garden center’s inventory or develop specific targets through research in a library or the Internet, or at Cabrillo College, in Aptos, whose salvia collection has been called the worlds largest. Most salvias should be cut back hard in the early spring, when new growth can be seen at the base of the plant.
Penstemon gets its name from a long straight, hairy fifth stamen that gives the blossom the appearance of an open mouth with a fuzzy tongue protruding. This inspires the plant’s common name, beardtongue. This is a large genus native to North America, from Alaska to Guatemala. There are taller-growing species (two-to-four feet) that can be fine additions to the middle of the border, and look best in mass plantings. There are also lower-growing species that are fine for rock gardens or the front of the border. Blossom colors include white, yellow (rare), blue, violet, purple, pink, magenta, and red. A popular selection is P. heterophyllus ‘Margarita BOP’, also called ‘Blue Bedder’. (BOP means “back of porch,” which is where this plant was discovered.)
Prepare to plant perennials in October!
Several species of lavender (Lavandula) are available. The most popular garden varieties are English Lavender (see above), French Lavender (L. stoechas or L. dentata) and Spanish Lavender (L. stoechas, L. lanata or L. dentata). There is also Egyptian Lavender (L. multifida). All Lavenders flourish best in dry, well-drained, sandy or gravelly soils in full sun, and require no fertilizer and good air circulation.
Visit Cabrillo College’s website of salvia information, and browse through the several pages for the collection, the photos of selected salvias, the chart of several species, and the Cabrillo cultivars.
Another exceptional resource for both information about, and purchases of salvias is the website of Flowers by the Sea, a mail-order nursery in Elk, California (which is about fifteen miles east of Fresno). Owner Kermit Carter tells me that Flowers by the Sea currently offers 369 species and varieties of Salvias, which is extraordinary indeed.
To learn more about Penstemons, start by visiting the website of the American Penstemon Society, which has solid information about cultivating, propagating, and identifying plants in this large genus from North American and East Asia.
Another good source of information is the website of Las Pilitas Gardens (located in Santa Margarita, California), particularly the page titled, California “Penstemons That Grow in DRY Areas.”
The best online information on almost any gardening subject is Wikipedia. Visit its webpage on the genus Penstemon for impressive details including a long list of species, and a list of Penstemon cultivars that the Royal Horticultural Society has honored with its Award of Garden Merit.