StoX® Silver
Matthiola incana
Wikimedia Commons via Matthiola incana
Sturdy, upright stems are comparable in quality to the Iron series. The StoX series was bred for easier selection of double-flowering plants. Double-flowering plants will display a lighter leaf color at the seedling stage after exposure to cool temperatures. Without selection your plants will produce approximately 55% double-flowering plants and 45% single-flowering plants. You might notice that some seedlings will present the lighter color leaves, even without a cold treatment. Single-stem/column-type stock for one-cut harvest. NOTE: This variety produces one flowering stem per plant. Pinching is not advisable as it will terminate flowering. Blooms are pale pink in color. Edible Flowers: The peppery, clove-like flavor of the flowers lends itself well to use as a garnish on salads, desserts, and drinks.
Harvest
90-105d
Days to harvest
Sun
Full sun to partial shade
Zones
6–10
USDA hardiness
Height
1-3 feet
Planting Timeline
Showing dates for StoX® Silver in USDA Zone 7
All Zone 7 flower →Zone Map
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StoX® Silver · Zones 6–10
Growing Details
Zone-by-Zone Planting Calendar
| Zone | Indoor Start | Transplant | Direct Sow | Harvest |
|---|---|---|---|---|
| Zone 3 | April – May | June – July | June – August | — |
| Zone 4 | March – April | June – June | June – July | — |
| Zone 5 | March – April | May – June | May – July | — |
| Zone 6 | March – April | May – June | May – July | — |
| Zone 7 | February – March | April – May | April – June | — |
| Zone 8 | February – March | April – May | April – June | — |
| Zone 9 | January – February | March – April | March – May | — |
| Zone 10 | January – January | February – March | February – April | — |
| Zone 1 | May – June | July – August | July – September | — |
| Zone 2 | April – May | June – July | June – August | — |
| Zone 11 | January – January | January – February | January – March | — |
| Zone 12 | January – January | January – February | January – March | — |
| Zone 13 | January – January | January – February | January – March | — |
Succession Planting
Stock is a one-flush crop — each plant puts up its spike and that's largely it — so succession planting is how you get a steady cut-flower supply instead of one big glut. In zone 7, sow indoors every 3 weeks from early February through mid-March, then direct sow or transplant every 3 weeks from April through early June. Stop once daytime highs are consistently hitting 80°F; Matthiola sets buds in cool conditions (ideally 45-65°F nights), and plants started in summer heat will bolt to short, poorly-formed spikes without that cool-night trigger.
Complete Growing Guide
Sturdy, upright stems are comparable in quality to the Iron series. The StoX series was bred for easier selection of double-flowering plants. Double-flowering plants will display a lighter leaf color at the seedling stage after exposure to cool temperatures. Without selection your plants will produce approximately 55% double-flowering plants and 45% single-flowering plants. You might notice that some seedlings will present the lighter color leaves, even without a cold treatment. Single-stem/column-type stock for one-cut harvest. NOTE: This variety produces one flowering stem per plant. Pinching is not advisable as it will terminate flowering. Blooms are pale pink in color. Edible Flowers: The peppery, clove-like flavor of the flowers lends itself well to use as a garnish on salads, desserts, and drinks. According to Johnny's Selected Seeds, StoX® Silver is 90 - 105 days to maturity, annual, open pollinated. Notable features: Use for Cut Flowers and Bouquets, Fragrant.
Light: Full sun (6 or more hours of direct sunlight a day), Partial Shade (Direct sunlight only part of the day, 2-6 hours). Soil: Clay, High Organic Matter, Loam (Silt), Sand. Soil pH: Alkaline (>8.0), Neutral (6.0-8.0). Drainage: Good Drainage, Moist. Height: 1 ft. 0 in. - 3 ft. 0 in.. Spread: 0 ft. 9 in. - 1 ft. 6 in.. Spacing: Less than 12 inches, 12 inches-3 feet. Growth rate: Rapid. Maintenance: Low. Propagation: Seed. Regions: Coastal, Mountains.
Harvesting
StoX® Silver reaches harvest at 90 - 105 days from sowing per Johnny's Selected Seeds. As an annual, harvest continues until frost ends the season.
Seeds will ripen in August and September.
Harvest time: Fall
Storage & Preservation
StoX® Silver cut flowers should be placed in cool water immediately after harvest. Store in a cool location (65-70°F) with high humidity, preferably in the refrigerator if not displaying immediately. Shelf life is typically 7-10 days in a vase with fresh water changed every 2-3 days. For preservation, air-dry stems by hanging upside down in a dark, well-ventilated area for 1-2 weeks to create long-lasting dried arrangements. Alternatively, press individual flowers between paper for botanical crafts. Freeze petals in ice cubes with water for decorative beverage garnishes.
History & Origin
StoX® Silver is open-pollinated, meaning seed saved from healthy plants will produce true-to-type offspring. Listed in the Johnny's Selected Seeds catalog.
Origin: The Coast of Europe from Spain to Greece.
Advantages
- +Sturdy upright stems match quality of premium Iron series stock
- +Easier double-flower selection with distinctive lighter leaf color indicator
- +Produces approximately 55% doubles without requiring cold treatment selection
- +Beautiful pale pink blooms with edible peppery-clove flavor for garnishing
- +Quick 90-105 day timeline makes efficient use of greenhouse space
Considerations
- -Single stem per plant means no pinching allowed or flowering stops
- -Fixed ratio of 45% singles requires culling if all doubles needed
- -Limited to one-cut harvest per plant reduces operational flexibility
Companion Plants
Marigolds and nasturtiums are the most practical neighbors here — marigolds produce thiophene compounds from their roots that deter aphids (which do probe Matthiola stems), and nasturtiums act as a trap crop, pulling those same aphids away from the flower spikes you're cutting. Sweet alyssum brings in parasitic wasps that knock back pest pressure across the whole planting, and its low, spreading habit doesn't steal light. Black walnut is the one to plant far from — juglone leaches from roots into surrounding soil and will stunt or kill stock outright. Fennel belongs in its own isolated bed; its root exudates suppress most nearby annuals, and stock is not an exception.
Plant Together
Cosmos
Attracts beneficial insects and provides height variation in plantings
Marigolds
Repel nematodes, aphids, and whiteflies while attracting beneficial insects
Sweet Alyssum
Attracts beneficial insects like lacewings and provides ground cover
Nasturtiums
Act as trap crops for aphids and cucumber beetles, protecting main plants
Petunias
Repel aphids, tomato hornworms, and other garden pests
Lavender
Deters moths, fleas, and mice while attracting pollinators
Zinnia
Attracts beneficial predatory insects and provides complementary colors
Catmint
Repels ants, aphids, and cabbage looper while attracting bees
Keep Apart
Black Walnut
Produces juglone toxin that inhibits growth of many flowering plants
Eucalyptus
Releases allelopathic compounds that suppress nearby plant growth
Fennel
Inhibits growth of most garden plants through allelopathic root secretions
Troubleshooting StoX® Silver
What you'll see, why it happens, and what to do about it.
Gray fuzzy mold covering buds or stems, especially after a stretch of cool, wet weather
Likely Causes
- Botrytis cinerea (gray mold) — thrives below 65°F with high humidity and poor airflow
- Overcrowded spacing that traps moisture between plants
What to Do
- 1.Remove and bag any affected tissue immediately — don't compost it
- 2.Thin plants to at least 12 inches apart and pull any dead leaves from the base
- 3.Water at soil level in the morning, not overhead in the evening
Lower leaves show yellow-green patches on top with a grayish-purple fuzz underneath, spreading upward
Likely Causes
- Downy mildew (Peronospora parasitica) — a brassica-family pathogen that hits stock hard in cool, damp springs
- Plants set too close together or grown in a low-drainage spot
What to Do
- 1.Strip affected leaves and dispose of them in the trash
- 2.Apply a copper-based fungicide (follow label rates) at first sign and repeat every 7-10 days if conditions stay wet
- 3.Rotate the bed out of brassicas and brassica-family flowers for at least one full season
Spindly stems, pale foliage, and few flower spikes despite adequate sun
Likely Causes
- Nitrogen deficiency from lean or sandy soil with no amendment
- Root competition from spacing tighter than 12 inches
- Seedlings started indoors without sufficient light — under 14 hours per day — producing weak transplants
What to Do
- 1.Side-dress with a balanced 10-10-10 fertilizer at about 1 tablespoon per plant, worked shallowly into the soil
- 2.Thin to 12-18 inches if you haven't already
- 3.Give indoor seedlings 14-16 hours of light daily — a south-facing window almost never delivers that without supplemental grow lighting
Frequently Asked Questions
How long does it take for StoX® Silver to bloom?▼
Can I grow StoX® Silver stock in containers?▼
Is StoX® Silver good for beginners?▼
What does StoX® Silver taste like and how is it used?▼
When should I plant StoX® Silver?▼
How do I encourage double-flowering plants in StoX® Silver?▼
Can I pinch StoX® Silver for bushier growth?▼
Growing Guides from Wind River Greens
Where to Buy Seeds
Sources & References
External authority sources used in compiling this guide.
- BreederJohnny's Selected Seeds
See the Methodology page for how this data is sourced, what's AI-assisted, and known limitations.