Cane Bluestem

Year-round

Cane bluestem is a warm season bunchgrass most at home in Southern California and the desert Southwest. In a cooler, foggier Bay Area garden it can still work as an ornamental grass, but it will not grow quite the way it does in its native range.

• In California this grass grows natively from San Diego to Santa Barbara and into interior desert grasslands, not the coastal Bay Area, so expect slower and less vigorous growth in San Francisco's cooler, foggier summers than it would get further south or inland.
• Give it the sunniest, driest spot available. It wants full sun and fast draining soil, and struggles in shade or heavy clay that stays wet.
• It grows as a tidy bunching clump rather than spreading, so it stays put in a border once planted.
• Established plants need very little water. Overwatering or rich soil tends to make the clump floppy instead of holding its upright form.

Fall

Fall is a quiet season for cane bluestem, as the grass finishes flowering and its foliage shifts into fall color ahead of winter dormancy.

• Expect the blue green summer foliage to fade toward reddish yellow tones as the grass heads into dormancy.
• Leave the clump standing through fall. The dry seed heads and foliage give the bed some winter interest and shelter for birds and insects.
• Do not cut back yet. Wait until late winter, closer to when new growth is about to start, so the standing clump can protect the crown through the coldest weeks.

A cane bluestem clump looks increasingly dry and straw colored through fall. That fading is the grass's normal seasonal color change, not dieback, and it is best left standing rather than cut for a tidier look this early.

Winter

Winter is cane bluestem's dormant season. The clump goes mostly brown and stops active growth until temperatures warm again in spring.

• The grass is rated cold hardy well into freezing territory, roughly USDA zones 7 through 10, so the Bay Area's mild winters are not a limiting factor for this plant.
• Late winter, shortly before new growth starts, is the best time to cut the dry clump back to a few inches. Cutting too early removes winter shelter for wildlife, and cutting too late risks damaging fresh new blades.
• No winter watering is needed. Wet, poorly drained soil sitting through winter is more likely to cause problems than a lack of water.

Cutting the clump back to a few inches in late winter, right before new growth starts, gives the bed its neatest look heading into spring and matches standard ornamental grass maintenance.

Spring

Spring is when cane bluestem wakes up from winter and starts pushing new blue green blades from the base of last year's clump.

• New growth emerges from the base as temperatures warm. It is often slower to start in the Bay Area's cooler spring than it would be in its native desert grassland range.
• This is the last practical window to cut back any dry winter growth before new blades come in, if that was not already done in late winter.
• Hold off on fertilizer. This grass is adapted to lean soils, and heavy feeding tends to produce weak, floppy growth instead of its normal upright habit.

Cutting back the old dry clump in late winter or very early spring, before new blades emerge, keeps the bed looking tended rather than showing a mix of dead growth and new shoots.

Summer

Summer is cane bluestem's main growing and flowering season, when the clump fills out and sends up its distinctive fluffy seed heads.

• Flowering typically runs from around April through August, with the grass producing silvery, fringed seed heads above the foliage.
• It is drought tolerant and adapted to a warmer, drier summer than the Bay Area usually delivers. Give it full sun and skip extra irrigation beyond what an already established, low water bed gets.
• Foliage often takes on reddish or bronze tones as summer goes on. That is a normal color shift, not a sign of stress.