Why summer snapdragon is the perennial you can’t ignore

Angelonia angustifolia, commonly referred to as summer snapdragon, is a perennial whose time has come. I looked it up in my 2001 edition of the Sunset Western Garden Book — whose authoritative stature as a horticultural resource is unchallenged — but it was not listed there. Yet during the last two decades, it has gradually made its garden presence known to where it has become the most popular bedding plant for the summer garden. It will flower from May until October and is evergreen so that you can rely on it flowering for several years at least. 

Angelonia is difficult to propagate from seed but is readily propagated from cuttings. When full into its flush of spring growth, remove a three- to four-inch terminal section of a flowerless shoot. Dip the detached shoot tip in root hormone and place it in fast-draining potting soil in bright light, but sheltered from pounding sun. 

Incidentally, common snapdragons can be propagated from cuttings as well. In their case, wait until fall arrives and then take shoot mid-sections that are four to six inches in length before giving them the same treatment as summer snapdragon cuttings. Both Angelonia and common snapdragon (which is a perennial even if seldom treated at such) may also be propagated in spring or fall by digging up the root ball and dividing it, being careful to untangle the roots without cutting them. Each root section, as long as some stem or shoot growth is attached, can then be planted out in the garden or in a container.

Angelonia’s habitat stretches from Mexico to Argentina and thrives especially where arid conditions prevail for much of the year. Angelonia is one of those plants fancifully classified as “a thriller, a filler, and a spiller.” This means that it plant that brings excitement and thrills due to  a certain outstanding quality (in this case, the vivid mass of flowers on display); it can nicely fill a flower bed or a container with its thick block of blooms; growing out to two feet in every direction, it can put on such explosive growth that it spills right out of the pot or hanging basket. 

Other qualities distinguish Angelonia from most summer-blooming fare. Angelonia can take the sun’s most intense heat with minimal water. Its flowers do not require dead-heading but the plants will grow more compact if they are occasionally pruned back. Similar to snapdragons, Angelonia cut lowers can last more than a week in a vase. Unlike snapdragons, Angelonia is not afflicted by insect pests or diseases. Angelonia flowers appear in pink, red, blue, violet or white.

Both snapdragon and Angelonia are members of Plantaginaceae, the plantain family, which does not include the banana-like plantain plant. However, this family does include a genus that has no parallel in the plant kingdom, in my opinion. The genus is Hebe and its flowers are unforgettable fuzzy cylinders or cones in blue, lavender, purple or pink. Plant forms range from mat-like ground covers to leafy shrubs more than 10 feet tall although, in the nursery trade, we see dwarfish sub-shrubs alone. Foliage may be variegated — green in the center surrounded by a thick creamy white margin, or foliage may emerge purple before turning green and cream. Hebe (HEE-bee) is Greek for “bloom of youth.” It is a prescient moniker since the species that comprise the genus seldom live more than a decade. But oh what a wonderful decade it is! Still, you would be wise to propagate your Hebe from shoot-tip cuttings before its predictably early demise.

Although Hebes are recommended for perfectly drained soil, I have seen them prosper where soil was somewhat compacted. I would not plant a whole hedge where soil drainage is questionable, but it might be worth trying a plant or two in such soil — as long as the planting-hole backfill is 30% soil amendment — as an experimental project.  Hebe, in fact, has also been known to suffer in sandy soil from inadequate moisture so, during hot weather, water it at least twice a week where soil drains quickly, keeping the surrounding ground covered with mulch. You can order two species of Hebe — one growing to two feet and the other to three feet tall — from Annie’s Annuals and Perennials (anniesannuals.com).

California native of the week: If you don’t have an island bush poppy, native to the Channel Islands, you might want to consider planting one. Ever since being introduced to the island bush poppy (Dendromecon harfordii) many years ago, I have yet to find a plant to which it could be remotely compared. Its foliage is green to blue-green to blue-grey, depending on how the sun strikes it at a particular moment, but its flowers are always an unmistakably bright and buttery yellow. It blooms from spring into early summer. It can grow into a large shrub or small tree to a height of 20 feet. The ordinary bush poppy (Dendromecon rigida) is smaller, grows eight feet tall and six feet wide and is thus more manageable in the garden, although its flower display cannot compete with that of its bigger island-living cousin.

Do you have any flowering plants to recommend for hot weather growing? If so, please send your recommendations to joshua@perfectplants.com. Your questions, comments, gardening predicaments and stories about gardening successes or favorite plants are always welcome.