Zone 8 · winter lows 10°F to 20°F

May garden checklist for Zone 8

Every May job that matters, limited to plants that actually survive Zone 8 winters (10°F to 20°F). Last frost lands around late March.

11 tasks this month30+ in bloomFirst frost ~mid-November

Plant in May

Plant in spring. Has a deep taproot, so choose a permanent location.

Prune in May

Pinch back stems by 1/3 before mid-summer (Chelsea Chop) for bushier plants

Divide in May

Divide large clumps in late spring if center becomes weak.

Fertilize in May

Apply balanced slow-release fertilizer in spring and mid-summer

Deadhead in May

Remove individual spent spikes to maintain a tidy appearance

Mulch in May

Apply a 2-3 inch layer of mulch to conserve moisture and suppress weeds.

Check for Pests in May

Check for bright yellow oleander aphids; a strong spray of water can dislodge them.

Stake in May

Install tall stakes early to support heavy flower spikes and prevent wind damage.

Pinch Tips in May

Pinch back stems by half before mid-June for bushier growth and less flop

Propagate in May

Take softwood cuttings to start new plants

Harvest in May

For arrangements, cut stems and sear ends with a flame to stop milky sap.

What's blooming in May

In flower around now and hardy in Zone 8.

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

May questions

What should I be doing in my Zone 8 garden in May?

The jobs that matter most this month are plant, prune, divide, fertilize. Each section above lists the specific plants that need that job in May, filtered to what survives Zone 8 — drawn from the care schedules of the plants gardeners actually grow.

When is the last frost in Zone 8?

In Zone 8, the last spring frost typically lands around late March and the first fall frost around mid-November, with winter lows of 10°F to 20°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 May?

May Night Sage, Walker's Low Catmint, Dwarf Wild Indigo, Prairie Phlox, Wild Lupine and others are in flower around now in Zone 8. The full list is above.

Keep exploring

Get May'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