Western silver aster

Year-round

Western silver aster is a low, silvery leaved native aster that covers itself in small violet purple, yellow centered flowers late in the growing season. It wants full sun and very little water once it has a season in the ground.

• Plant in full sun. It needs at least 6 hours of direct sun a day to bloom well and stay compact instead of flopping open.
• Give it dry, fast draining soil. In heavy black clay, plant it high on a slight mound or amend the hole for drainage; in the sandier soils west of the metro it drains on its own but will need water more often through its first summer.
• Space plants 12 to 18 inches apart. It slowly forms a small mounded clump 1 to 2 feet tall and a bit wider over a few seasons.
• It is a larval host plant for the pearl crescent butterfly, so expect some chewed leaves in late summer. That is the plant doing its job, not a pest problem to treat.

Summer

Once established this plant is built for the hard part of a North Texas summer. It will not bloom yet, but it should hold its silvery low mound through the heat with little help.

• An established plant (its second summer or later) needs no supplemental water except during a stretch of three or more weeks without rain.
• A first-summer plant still needs a deep soak once a week during July and August, the stretch when new plantings are most likely to die here.
• Do not mulch heavily against the base. This aster wants dry air and dry soil around its crown, thick mulch invites rot in our humidity.
• If the lower leaves yellow and drop in the driest weeks, that is normal drought response, not a sign to add water.

Fall

Fall is this plant's moment. From September into October it is covered in small violet purple, yellow centered flowers right as most of the yard is winding down.

• Expect peak bloom in September and October, the plant's only bloom window for the year.
• Leave the flowers in place rather than deadheading. The seed heads that follow feed goldfinches and sparrows through fall.
• Watch for caterpillars on the leaves in late summer into fall. Those are pearl crescent butterfly larvae using the plant as a host, not a pest to spray.
• This is also a good month to divide an overcrowded clump, digging and splitting the root mass into two or three sections to replant or share.

A blooming clump reads as a deliberate, tidy fall accent, a low mound of small flowers rather than anything that looks unkempt. Point to the bloom if a neighbor asks what it is.

Winter

North Texas winters are mild with only short hard freezes, and this aster goes fully dormant, dying back to a low rosette at the base.

• Leave the dried stems standing through winter rather than cutting them to the ground. Hollow stems and leaf litter shelter overwintering insects, including caterpillars from the fall generation.
• Cut the whole clump back to about 3 inches only in late February, just before new spring growth starts, if you want a tidier look sooner.
• No winter watering is needed in a normal year. Water only during an extended dry spell with no rain for several weeks.
• A hard, multi-day Arctic outbreak will brown the top growth further, but the root crown of an established plant handles it fine; do not replant early from that alone.

Standing dried stems can look neglected to a passerby. If tidiness matters more than the wildlife benefit this winter, cut back in December instead of waiting for late February.

Spring

Spring is the best time to get a new western silver aster in the ground here, while the soil is still cool and rain is more regular.

• Plant any time after the last frost in mid March through May, while spring rain is doing most of the watering for you.
• Water a new plant twice a week for its first three to four weeks so the roots can spread before the summer heat arrives.
• Cut back any dried flower stalks left standing from last fall to about 3 inches once new green growth appears at the base.
• Skip fertilizer. This plant is bred for lean, low fertility soil and rich soil makes it floppy and less compact.

A young plant is low and unremarkable in spring, nothing to explain to a neighbor yet.

Year-round

Western silver aster is a low, silvery leaved native aster that covers itself in small violet purple, yellow centered flowers late in the growing season. It wants full sun and very little water once it has a season in the ground.

• Plant in full sun. It needs at least 6 hours of direct sun a day to bloom well and stay compact instead of flopping open.
• Give it dry, fast draining soil. In heavy black clay, plant it high on a slight mound or amend the hole for drainage; in the sandier soils west of the metro it drains on its own but will need water more often through its first summer.
• Space plants 12 to 18 inches apart. It slowly forms a small mounded clump 1 to 2 feet tall and a bit wider over a few seasons.
• It is a larval host plant for the pearl crescent butterfly, so expect some chewed leaves in late summer. That is the plant doing its job, not a pest problem to treat.

Summer

Once established this plant is built for the hard part of a North Texas summer. It will not bloom yet, but it should hold its silvery low mound through the heat with little help.

• An established plant (its second summer or later) needs no supplemental water except during a stretch of three or more weeks without rain.
• A first-summer plant still needs a deep soak once a week during July and August, the stretch when new plantings are most likely to die here.
• Do not mulch heavily against the base. This aster wants dry air and dry soil around its crown, thick mulch invites rot in our humidity.
• If the lower leaves yellow and drop in the driest weeks, that is normal drought response, not a sign to add water.

Fall

Fall is this plant's moment. From September into October it is covered in small violet purple, yellow centered flowers right as most of the yard is winding down.

• Expect peak bloom in September and October, the plant's only bloom window for the year.
• Leave the flowers in place rather than deadheading. The seed heads that follow feed goldfinches and sparrows through fall.
• Watch for caterpillars on the leaves in late summer into fall. Those are pearl crescent butterfly larvae using the plant as a host, not a pest to spray.
• This is also a good month to divide an overcrowded clump, digging and splitting the root mass into two or three sections to replant or share.

A blooming clump reads as a deliberate, tidy fall accent, a low mound of small flowers rather than anything that looks unkempt. Point to the bloom if a neighbor asks what it is.

Winter

North Texas winters are mild with only short hard freezes, and this aster goes fully dormant, dying back to a low rosette at the base.

• Leave the dried stems standing through winter rather than cutting them to the ground. Hollow stems and leaf litter shelter overwintering insects, including caterpillars from the fall generation.
• Cut the whole clump back to about 3 inches only in late February, just before new spring growth starts, if you want a tidier look sooner.
• No winter watering is needed in a normal year. Water only during an extended dry spell with no rain for several weeks.
• A hard, multi-day Arctic outbreak will brown the top growth further, but the root crown of an established plant handles it fine; do not replant early from that alone.

Standing dried stems can look neglected to a passerby. If tidiness matters more than the wildlife benefit this winter, cut back in December instead of waiting for late February.

Spring

Spring is the best time to get a new western silver aster in the ground here, while the soil is still cool and rain is more regular.

• Plant any time after the last frost in mid March through May, while spring rain is doing most of the watering for you.
• Water a new plant twice a week for its first three to four weeks so the roots can spread before the summer heat arrives.
• Cut back any dried flower stalks left standing from last fall to about 3 inches once new green growth appears at the base.
• Skip fertilizer. This plant is bred for lean, low fertility soil and rich soil makes it floppy and less compact.

A young plant is low and unremarkable in spring, nothing to explain to a neighbor yet.