Orton Botanical Garden is located on the northerly fringes of the Great Basin Desert. The average annual precipitation here in south central Idaho is 10 inches. The garden demonstrates landscaping that requires minimal irrigation or in some cases no irrigation at all. There are over 400 species and varieties of plants demonstrated in the garden, including many Idaho native plants, as well as plants from the southwest and other dry climates around the U.S. and a few other countries.
Following is a list of drought tolerant plants that we have found do well in south central Idaho. It is not intended to be an all inclusive list.
This tall slender evergreen is an excellent plant that looks similar to the Italian cypress commonly grown in warmer climates. It grows to 4' wide and up to 30' tall. Excellent for use as a single focal specimen, for screens and buffers. Requires no trimming to keep its form.
Native in southern Idaho. Very xeric and reaches 20' tall. As it ages, it can take on unusual and interesting forms.
This evergreen plant is native in Idaho and throughout much of western USA. It grows to 16', but is can be trimmed easily and can be used as a hedge plant.
Fern bush is an Idaho native plant that grows 5-6' tall x 6-8' wide. It is semi evergreen and greens up quickly in early spring. It blooms late in summer and attacks many native pollinators and honey bees. Easy to trim and keep at any desired size. Foliage has a pleasant odor.
This deciduous desert plant is native to the southwestern USA and Mexico. It can grow to 15'-20' high. In Idaho it starts showing leaves in late May, starts blooming in late June and continues to bloom the rest of the summer. The flower color varies depending on where the plants originate. Lucretia Hamilton and Art's Seedless cultivars have grown well in Idaho and have purple flowers.
This evergreen shrub can reach 3' to 6' high and about the same in width. It has small white flowers in early spring that are fragrant. This plant does much better in a xeric garden than our Idaho native Ceanothus velutinus.
This very xeric plant is 4" tall x 15" wide spreading with underground roots. Excellent for stabilizing soils. It blooms from June until frost.
This beautiful native plant is 4-6" tall x 15-18" wide spreading with underground roots. It blooms in mid to late summer. Hummingbirds love it.
This night blooming southwest native has beautiful purple flowers from mid summer until frost. The plants can reach 2'-3' high and as much as 10' or more wide. After frost they die all the way back to their large underground tubers.
This southwest yucca is the largest yucca native to the USA. It can reach a height of 40', but usually stays much smaller in colder climates. Plants from the northerly part of its range will usually do well in Idaho. Once it is established it needs little irrigation. They bloom in early May here in Idaho.
This beautiful blue yucca is native to west central Utah and east central Nevada. It can reach 3' - 5' high and wide. The white flowers bloom well above the leaves in May.
This desert yucca is common throughout much of southwestern USA. When it blooms, its flowers are held within its leaves. The fruits look somewhat like a banana. It can reach 5' high and 6' wide here in Idaho. As there are no yucca moths in Idaho, fruits rarely form on the plants.