Zone 10 · winter lows 30°F to 40°F

August garden checklist for Zone 10

Every August job that matters, limited to plants that actually survive Zone 10 winters (30°F to 40°F). Last frost lands around rare.

7 tasks this month30+ in bloomFirst frost ~rare

Plant in August

Plant rhizomes shallowly in late summer/early fall

Prune in August

Cut flower stalks down to the base after blooming finishes.

Divide in August

Divide crowded clumps every 3-5 years in late summer or early fall

Fertilize in August

Feed with a balanced liquid fertilizer every 4-6 weeks.

Deadhead in August

Remove spent blooms to encourage more flowers, or leave seed heads for birds

Check for Pests in August

Watch for powdery mildew; ensure good air circulation.

Harvest in August

Harvest fruit (maypops) when they are yellowish and drop from the vine.

What's blooming in August

In flower around now and hardy in Zone 10.

Frost dates and bloom windows are typical ranges, not guarantees — your microclimate moves them by weeks. Sow uses your real local forecast instead.

August questions

What should I be doing in my Zone 10 garden in August?

The jobs that matter most this month are plant, prune, divide, fertilize. Each section above lists the specific plants that need that job in August, filtered to what survives Zone 10 — drawn from the care schedules of the plants gardeners actually grow.

When is the last frost in Zone 10?

In Zone 10, the last spring frost typically lands around rare and the first fall frost around rare, with winter lows of 30°F to 40°F. Those two dates bracket most planting decisions — check your local forecast before acting on either, since microclimate and elevation shift them by weeks.

What's blooming in August?

Eastern Silver Aster, Lilyturf, Pink Muhly Grass, Immortality Tall Bearded Iris, Ravenna Grass and others are in flower around now in Zone 10. The full list is above.

Keep exploring

Get August's tasks for your own plants

Sow builds this checklist from the plants actually in your yard — and adjusts it to your real forecast, so a wet week skips the watering and a frost warning reaches you first.

Download Sow on the App StoreGet Sow on Google Play