StoX® Yellow
Matthiola incana
Photo: Julien Bertrand · Wikimedia Commons · (Public domain)
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. Creamy yellow blooms are similar in color to Iron Yellow and Katz Yellow. 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® Yellow in USDA Zone 7
All Zone 7 flower →Zone Map
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StoX® Yellow · 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 sends up its spike, blooms, and that's it. You won't get a second cut from the same plant, so staggered sowings are the only way to stretch the season. In zone 7, start seeds indoors every 3 weeks from early February through mid-March, then transplant out in April and into early May. That gives you two or three staggered flushes before daytime highs push past 85-90°F, at which point stock bolts fast and the flower spikes come in short and loose.
Don't push a late sowing past mid-June in Georgia — the heat arrives before those plants can build a decent stem. If you want fall stock, start seeds again indoors in late August and move transplants out in September once daytime temperatures drop back below 80°F.
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. Creamy yellow blooms are similar in color to Iron Yellow and Katz Yellow. 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® Yellow 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® Yellow 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
For fresh storage, keep StoX Yellow flowers on the counter in a cool room (65-70°F) in a vase with fresh water, changing water daily for 5-7 days shelf life. Alternatively, refrigerate at 35-40°F in water to extend freshness to 10-14 days. For preservation: (1) Air dry by hanging stems upside-down in a dark, well-ventilated space for 1-2 weeks to create long-lasting dried flowers. (2) Press flowers between parchment paper under heavy weights for 2-3 weeks for floral arrangements or craft use. (3) Freeze flowers in ice cubes with water for decorative cocktail garnishes, storing up to 3 months.
History & Origin
StoX® Yellow 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 Iron series quality for professional arrangements
- +Creamy yellow blooms comparable to Iron Yellow and Katz Yellow varieties
- +Double-flowering plants identifiable by lighter seedling leaves after cool exposure
- +Edible flowers with peppery clove flavor enhance salads and cocktails
- +Single-stem column type produces one clean cut per plant
Considerations
- -Approximately 45% single-flowering plants without intentional selection during production
- -Pinching terminates flowering, limiting design flexibility for multi-stem arrangements
- -Requires cool temperature exposure to reliably identify double-flowering seedlings
- -90-105 days to flowering is longer than some competing stock varieties
Companion Plants
Marigolds — French types especially — are worth planting within 12-18 inches of stock. Their scent deters aphids and they pull in predatory wasps and hoverflies that cut into cabbage looper populations before the damage gets bad. Sweet alyssum works the same angle: it blooms fast from transplant, stays low enough not to crowd stock's spike, and keeps those same parasitic wasps fed and on-site. Nasturtiums are a reasonable addition as a trap crop, drawing aphid pressure away from stock before it concentrates on your stems.
Black walnut is a hard no — the roots and decomposing leaf litter release juglone, a compound that disrupts cellular respiration in a wide range of plants, and Matthiola isn't going to be the exception. Sunflowers are less dramatic but still a problem: in our zone 7 Georgia gardens, they put on 2-3 feet of growth during the same late-April window when stock is trying to establish, and the shade they cast by early May lands right where stock needs full sun to set a decent flower spike.
Plant Together
Marigolds
Repel nematodes, aphids, and other pests while attracting beneficial insects
Nasturtiums
Act as trap crops for aphids and cucumber beetles, attract predatory insects
Sweet Alyssum
Attracts beneficial insects like lacewings and parasitic wasps for natural pest control
Petunias
Repel aphids, tomato hornworms, and squash bugs naturally
Cosmos
Attract beneficial pollinators and predatory insects while providing visual contrast
Zinnia
Attract butterflies and beneficial insects, complement yellow blooms with vibrant colors
Lavender
Repels moths, fleas, and mosquitoes while attracting pollinators
Catnip
Natural insect repellent, particularly effective against mosquitoes and ants
Keep Apart
Black Walnut Trees
Release juglone toxin that inhibits growth and can kill sensitive flowering plants
Eucalyptus
Allelopathic compounds in leaves and roots suppress growth of nearby plants
Sunflowers
Release allelopathic chemicals and compete aggressively for nutrients and water
Pests & Disease Resistance
Common Pests
Cabbage looper, diamondback moth, aphids
Diseases
Clubroot, damping off, root rot
Troubleshooting StoX® Yellow
What you'll see, why it happens, and what to do about it.
Seedlings collapse at the soil line within the first 2 weeks after germination
Likely Causes
- Damping off (Pythium or Rhizoctonia spp.) — fungal pathogens that thrive in cold, wet, poorly drained starting mix
- Overwatering combined with low airflow around seedling trays
What to Do
- 1.Toss the affected tray — there's no saving seedlings that have already damped off
- 2.Start fresh with a sterile, well-draining seed-starting mix and water only when the top 1/2 inch is dry
- 3.Run a small fan near your trays for 30-60 minutes a day to keep surface moisture down
Leaves are pocked with irregular holes and you find green or white caterpillars on the undersides, especially in spring
Likely Causes
- Cabbage looper (Trichoplusia ni) — a moth larva that feeds on brassica-family plants, and stock (Matthiola) is in that family
- Diamondback moth (Plutella xylostella) larvae, which are smaller and wriggle off the leaf when disturbed
What to Do
- 1.Spray Bt (Bacillus thuringiensis) on the foliage every 5-7 days while caterpillars are active — it only kills larvae, not beneficial insects
- 2.Check the undersides of leaves every few days and hand-pick any egg clusters or small caterpillars you find
- 3.Cover transplants with row fabric immediately after planting to block adult moths from laying eggs
Plants are stunted, yellowing, and when you pull one up, the roots look swollen and distorted — almost like small galls
Likely Causes
- Clubroot (Plasmodiophora brassicae) — a soil-borne pathogen that persists for 10+ years in infected beds
- Planting stock in soil with a pH below 6.5, which favors clubroot development
What to Do
- 1.Pull and bag every affected plant immediately — don't compost them
- 2.Raise soil pH to 7.0-7.2 with agricultural lime before the next planting season; clubroot is suppressed above pH 7.0
- 3.Rotate stock and other brassica-family crops out of that bed for at least 4 years
Frequently Asked Questions
How long do StoX Yellow flowers last in a vase?▼
Can you grow StoX Yellow stock in containers?▼
What does StoX Yellow taste like as an edible flower?▼
How long does it take to grow StoX Yellow from seed to harvest?▼
Is StoX Yellow stock good for beginners?▼
Can I get double flowers without cold treatment on StoX Yellow?▼
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.