Here are three hardy, xeric and floriferous plants that are successful in western gardens.
Russian Hawthorn, Crataegus ambiguus was tested at the Cheyenne Horticultural Station and found to be well-adapted to the west. It is native to Armenia, Iran, Russia, Ukraine and Turkey. I have a 20 year-old specimen growing without irrigation along with many native shrubs. The mature size is 15′-20′ high and wide in our area. The branches grow quite horizontally which gives it natural character. It lends itself to a bonsai/character style, and I have been growing one in a big ceramic pot for 10 years. The finely cut leaves give a soft appearance and in May it blooms with profuse white flowers that are attractive to bees and butterflies and followed by showy red berries in August/September that are eaten by birds. Very dry conditions can result in fewer flowers and fruit. Like apples, to which Hawthorns are related, the seeds contain some cyanide, so should not be eaten, but the berries are edible and make a respected heart tonic.
Russian Hawthorn is usually propagated by seed and there are often variations in the prevalence of thorns. I have seen a few with practically no thorns and some that are quite thorny. The tree is deer resistant.
This pest-free tree is long-lived, tolerant of a variety of soils, actually liking our alkaline conditions, and is highly tolerant of urban pollution. It is hardy to zone 4. The fall color is yellow and the bark is a golden yellow. This is a great tree for planting under power lines or where a tall tree would block a good view. It was a Plant Select Winner in 2011.
Filigree Daisy, Anthemis marschalliana, is a very long-blooming and tough perennial. The very silvery, feathery foliage makes a mat that is beautiful by itself. It sets off the mass of 1″-1½” yellow daisies that stand on sturdy 10″ stems. These bloom for weeks in early summer in full sun or part shade. Filigree Daisy looks good as a single specimen or in groups, planted 8″-10″ apart. It performs well in a xeriscape or in a perennial garden, is not fussy about soils and will not seed about. The foliage does not decay after flowering as does Silver Mound Artemisia, but can deteriorate in wet winter conditions. It is a native of Turkey and is hardy to zone 4. It was promoted in 2012 as a Plant Select Introduction.
Penstemon rostriflorus, also known as Bridges’ Penstemon, is a summer bloomer with scarlet, tubular flowers that are magnets for hummingbirds and other pollinators. The very drought tolerant native of southwest Colorado, New Mexico and California, blooms in the hot summer, after many penstemons have finished. A dark evergreen mat pushes up 16″-30″ spikes of its showy red flowers. Bridges’ Penstemon is hardy to zone 4b, quite long-lived, and its life can be extended by dead-heading the first year, and removing half of the spent flowers afterward, to leave some seed to self-sow. It was a 2006 Plant Select Winner.
All of these sun-lovers have performed well in the low water conditions at Harlequin’s Gardens. They are among some of our favorites from the Plant Select Program.