Blooms late spring into summer, usually during the months of May and June.
This variety of cinquefoil has grown in my xeristrip for six years and flowers happily from late spring into fall, with moderate flowering during the heat of the summer. Will put on a new show of flowers after summer rain. It maintains a compact shape without pruning or any maintenance.
There are many other varieties of this wonderful North American native that grows throughout the Rocky Mountains. Other varieties require moderate watering. This variety was purchased from High Country Gardens; I have not seen this truly drought tolerant variety again.
Shadscale lives in alkaline caliche soil in most of its native range throughout the Southwest and has a high tolerance of saline or sodic soils. Given improved soil conditions, it will grow larger. Do not improve the soil to insure it keeps its neat, compact shape. Shadscale blooms yellow flowers in early summer which mature into seed heads. Its silver-gray leaves are semi-evergreen.
It's hard to pass up Johnson's blue geranium with the deep blue flower and interesting foliage. A hybrid cultivar, the most blue hardy geranium with delicate, finely cut leaves. Plant in your woodland border, medium water use. For a long time this was the most well know hardy geranium, or cranesbill, as this genus is commonly known.
When the name geranium is spoken most of the time, people are referring to the genus, Pelargonium, the red flowering perennial that is used extensively throughout the world. the common Pelargonium is only cold hardy to 28°.
Scabiosa columbaria ‘Butterfly Blue’, though first discovered in Ireland, will thrive very nicely in your transition zone as a border plant along turf, where it’ll receive medium to medium high water. Amend the soil well with organic matter for rich blooms and keep it deadheaded to prolong blooms. Afternoon shade is recommended. A little more trouble than usual, but well worth the softening effect this compact, mounded and cheery plant brings to the border; a Perennial Plant of the Year for 2000.
Similar in form to Callirhoe involucrata, Callirhoe alcaeoides 'Logan Calhoun' grows natively from the Midwest to southern plains. While Callirhoe alcaeoides can be pink, to pale pink and pale lilac, 'Logan Calhoun' is pure white. Spreads over an area similar to wine cups, the foliage and flowers are finer. I've found it to be drought tolerant; water monthly to insure continued blooms. Blooms will rest during the heat of the summer and continue following rains or cooler weather.