Stock Flowers (Matthiola): Timing, Spacing, Care & Bloom
Quick answer
Start indoors 6–12 weeks before last frost. Direct sow after last frost. Cool-season cut flower with clove-like fragrance.
Stock Flowers (Matthiola) at a glance
Weeks relative to last frost (LF). Colored weeks show when our ZIP planner schedules each step.
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Updated
Stock flowers are Matthiola incana (and related). Cool-season cut flower; spike bloom; does not rebloom strongly (UMN).
Sourced from university extension guides. For dates where you live, use the ZIP planting planner.
Planting timing
Purdue HO-14: stock — start indoors 12 weeks before last frost. (Purdue HO-14-W) NC State: start indoors 6 to 8 weeks before the last frost. (NC Matthiola) UMN cutting-garden: about 8–10 weeks before the last frost. (UMN cutting gardens) MSU: sow 8–10 weeks before transplanting; if direct-seeding, sow after last frost; space about 6-inch centers. (MSU stock) Succession every 1–2 weeks (NC/MSU) for extended harvest.
Depth and spacing
MSU: about 6-inch centers. Give air flow for cool-season spikes.
Sun, soil and water
Full sun; well-drained soil. Cool season — heat shortens bloom (cultural).
Care and bloom
Cut flower; clove-like fragrance (NC). Spikes; early cool season; does not rebloom strongly (UMN). Doubles preferred commercially (MSU).
Pests and diseases
Cultural spacing and drainage first.
Related: ZIP planner · planting calendars · Dianthus (China pink & Sweet William)
Frequently asked questions
When do I start stock?
6–12 weeks before last frost (−12/−6 by source); or direct after last frost (0).
What is Matthiola?
The botanical genus for stock flowers
Does it rebloom?
Not strongly — succession sow for more spikes (UMN/NC).
Sources
- Purdue University: Purdue HO-14-W
- NC State Extension: NC Matthiola
- University of Minnesota Extension: UMN cutting gardens
- Mississippi State University Extension: Stock matthiola incana for the farmer florist