Marsh-rosemary

Year-round

Western marsh rosemary, also called California sea lavender, is native to the California coast from Oregon south into Baja California, growing naturally in salt marshes, beaches, and other saline or seasonally flooded coastal habitat, a range that includes the Los Angeles coastline's remaining wetlands and beach edges. It forms a low rosette of thick, leathery leaves topped in summer and fall by branching sprays of small lavender to white flowers.

• Give it full sun and let it grow in whatever soil you have. It is genuinely adaptable and tolerates salty, alkaline, poorly drained, and even seasonally flooded soil better than almost anything else you might plant.
• Water low to moderately. It looks its best with some regular moisture through summer but also tolerates dry spells once established.
• It stays low, usually 1 to 2 feet tall and wide, forming a basal rosette rather than spreading aggressively.
• Its flowers draw native bees, butterflies, and hoverflies, and the dried flower clusters hold their color well if you want to cut some for arrangements.

Fall

Fall is a good planting window for western marsh rosemary in Los Angeles, and the tail end of its bloom season as flower clusters fade and dry on the plant.

• Plant new western marsh rosemary in fall so it can settle in before winter rain and next summer's dry season.
• Let spent flower stalks dry in place if you want them for dried arrangements, or cut them back once the color fades for a tidier look.
• If your yard has a spot with slow drainage or salty runoff, such as near a driveway edge or a low corner, this is a strong candidate plant for it.
• Established plants need little extra water once fall rain starts, though newly planted ones still need regular watering to establish roots.

Winter

Winter rain suits western marsh rosemary well since it is one of the few plants in this list that tolerates standing water and poor drainage without complaint.

• Let winter rain handle watering, including any spot in the yard that puddles after a storm. This plant is unusually tolerant of that.
• The basal rosette of leathery leaves generally stays evergreen through a mild Los Angeles winter.
• No pruning is needed this time of year beyond removing any fully dried leaves that have gone brown at the base.
• This is a fine season to plant if you missed the fall window, since Los Angeles winters are mild enough for roots to keep establishing.

Spring

Spring is a steady growth period for western marsh rosemary in Los Angeles as it builds toward its summer flower show.

• Watch for new leaves filling out the basal rosette as the plant comes out of its slower winter growth.
• Keep watering moderate. It does not need much more than what a typical Los Angeles spring provides between rains.
• If you are adding it near a salty or compacted spot in the yard, spring planting works, though fall is generally the better window for root establishment.
• Flower stalks typically begin forming toward the end of spring, ahead of the main summer to fall bloom.

Summer

Summer through fall is peak bloom for western marsh rosemary in Los Angeles, when its branching sprays of small lavender flowers are at their best.

• Water low to moderately through summer. A little regular moisture keeps the foliage looking fresh, though the plant will tolerate a dry stretch if you miss a watering.
• Full sun and summer heat are what push this plant into its best bloom, so do not worry about it looking stressed in the brightest part of the yard.
• Cut a few flower stalks for indoor arrangements if you like. The papery flowers hold their color well after drying.
• Check for good drainage if the plant is in a container or raised bed rather than the ground, since its wet tolerance mainly applies to garden soil, not stagnant water in a pot.

Its tidy, low rosette and long summer to fall bloom make it an easy plant to keep looking presentable in a front bed with little upkeep.