Heartleaf Or Common Blue Wood Aster

Year-round

Blue wood aster is a shade-friendly perennial with lots of small light blue daisies from late summer into fall. In Lancaster it does best in part shade with well-drained soil. It needs very little care but it will seed itself around.

• Part shade is best. Dappled sun or full sun is also fine.
• Well-drained soil that stays moist to dry. Poorly drained clay can lead to aster wilt.
• Grows about 1 to 4 feet tall and 1.5 to 2 feet wide.
• Pinch stems in late spring for a bushier plant that may not need staking.
• Moderately deer resistant.

It self-seeds and can get weedy, so pull extra seedlings and cut it back after bloom to keep beds looking tidy.

Fall

This is the show season. Light blue flowers cover the plant from late summer into fall until frost.

• Enjoy the bloom and skip fertilizer.
• Cut spent stems back if you do not want seedlings next year.
• Water only if fall turns dry for a couple of weeks.
• Rake leaves off the crown so it can breathe.

Winter

The plant is dormant through Lancaster winters and needs almost nothing.

• No watering is needed.
• Cut the old stems down any time from late fall to early spring.
• A thin layer of leaf mulch is fine. Keep it from piling on the crown.
• Mark the spot so you do not dig it up in spring.

Spring

New growth shows up as Lancaster warms in April. This is the time to set the plant up for a sturdy, tidy summer.

• Plant or move it now in part shade with soil that drains well.
• Water new plants about once a week if rain is under an inch.
• Pinch the stem tips in late spring so it branches and stays shorter.
• Pull extra seedlings while they are small.

Summer

Summer in Lancaster is warm and humid, which suits mildew and leaf spots. Space and airflow matter more than extra water.

• Give plants room so air can move between them.
• Watch for powdery mildew, leaf spots, and rust on the leaves.
• Water deeply during a dry spell, then let the top of the soil dry.
• Foliage looks worn by late summer. You can cut it to the ground to look neater and cut down on seedlings.

Year-round

Heartleaf blue wood aster is a low-fuss fall bloomer that likes part shade and soil that drains.

• Part shade, about 2 to 6 hours of direct sun, is its favorite. It also tolerates dappled light and full sun.
• Well-drained soil that runs moist to a little dry works. Aster wilt can happen in poorly drained clay.
• Pinching stems back makes it bushier and may mean no staking.
• It self-seeds freely and can get weedy, so trim before seed spreads.
• It is hardy in zones 3a to 8b, which covers Atlanta.

Cutting it back in late summer keeps the bed looking neat.

Fall

Fall is bloom time. Mostly enjoy it.

• Light blue flowers with yellow centers open from late summer into fall.
• Keep soil moist to occasionally dry, with good drainage.

Winter

Winter needs little. Cold is not a worry in Atlanta.

• Hardy to zone 3a, so Atlanta winters are mild for it.
• Keep drainage good so the roots do not sit wet.

Spring

Spring is the time to shape the plant and fix drainage.

• Pinch stems back as they grow to get a bushier plant.
• Check that clay beds drain, since poor drainage invites aster wilt.

Summer

Summer is for airflow and a late-summer tidy-up.

• Good air circulation lowers the chance of powdery mildew, leaf spots, and rust.
• Cutting foliage to the ground by late summer improves looks and limits self-seeding.
• Plants can reach 1 to 4 feet, and taller ones may need staking.