Flowers

Dianthus (China Pink & Sweet William): Timing, Spacing, Care & Bloom

Quick answer

China pink: start indoors about 8 weeks before last frost (Purdue). Sweet William: start 6–8 weeks before last frost (MSU/UAEX/Purdue); fall sow 6–8 weeks before first frost (UAEX).

Dianthus (China pink & Sweet William) at a glance

PlantStart indoors: 8 wk before last frost
SunFull sun; well-drained soil.
SpacingPSU: china pinks about 6–8 inches.
Days to bloomBloom season July–Oct. (Purdue HO-80)
-9-8-7-6-5-4-3-2-1LF+1+2+3
■ Start indoors   ■ Plant out   ■ Harvest
Weeks relative to last frost (LF). Colored weeks show when our ZIP planner schedules each step.
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Updated

Dianthus hub: china pink is Dianthus chinensis; Sweet William is D. barbatus. Neither is carnation (D. caryophyllus).

Safety: NC State poison severity Low for china pink — skin irritation. (NC Dianthus chinensis)

China pink flower
China pink (Dianthus chinensis). Photo: Gitartha.bordoloi, Wikimedia Commons, CC BY-SA 4.0 (resized).

Sourced from university extension guides. For dates where you live, use the ZIP planting planner.

China pink planting timing

Purdue HO-14: Dianthus — start indoors 8 weeks before last frost; frost tolerance after hardening medium. (Purdue HO-14-W) NC: grown primarily as annuals; full sun, afternoon shade in warm climates. (NC china pink) WSU “8–10 weeks sowing to transplant”.

Sweet William

Sweet William (Dianthus barbatus) is a related biennial/short-lived perennial — not china pink and not carnation. MSU: sow seeds 6–8 weeks before the last frost; harden and transplant 6–8 weeks after sowing. (MSU Sweet William) UAEX: indoors 6–8 weeks before the last frost, or sow 6–8 weeks before the first frost. (UAEX dianthus) Purdue Dianthus table supports ~8 weeks before last frost.

Depth and spacing

PSU: china pinks about 6–8 inches. (PSU sowing annual seeds)

Sun, soil and water

Full sun; well-drained soil. Afternoon shade in hot humid summers (NC).

Care and bloom

Deadhead for rebloom. Sweet William often blooms year two if biennial types.

Pests and diseases

Drainage first; avoid wet crowns.

Related: ZIP planner · planting calendars · garden phlox

Frequently asked questions

When do I start china pink?

About 8 weeks before last frost (Purdue).

Sweet William timing?

6–8 weeks before last frost indoors (MSU/UAEX); fall sow 6–8 weeks before first frost (UAEX).

Carnation?

No — different Dianthus species.

Sources