Ornamental · Brassicaceae
Stock
Matthiola incana
Give stock a cool head start and full sun, and watch it launch tall, sweetly scented spikes.
Full sun
Every 3–7 days
80–100 days
USDA 6–10
Overview
Stock is a joy to grow, packing tall spikes with bloom and throwing a clove-sweet scent that rides on cool air. It runs in the cabbage family, Brassicaceae, and powers along as a cool-season annual, hitting its stride in the mild weeks of spring and fall instead of high summer. Get the season right and this plant really goes.
Colors sweep through pink, purple, cream, and white on plants that shoot up 1 to 3 feet (30 to 91 cm) tall. The tall strains are a dream for cutting, sending up long, fragrant stems that keep going in a vase, and the compact ones pack a punch along an edge or in a pot.
One thing fires stock into bloom: cool weather while it sets its flowers. Plant it early to grab that chill, keep moisture steady, aim it at full sun, and it drives out weeks of bloom. Miss the cool window and let heat show up first, though, and it stalls out fast.
Care
The short version: stock thrives on full sun and cool weather, wants even moisture in fertile, well-drained soil that steers clear of acidic, and needs an early start so it flowers before summer heat rolls in. Hit those and it rewards you all season.
Light
Point stock at full sun and it builds the strongest stems and the biggest flush of bloom. A little partial shade works where spring heats up early, but heap on the shade and you get weak, leggy plants that barely flower.
Water
Never let stock run dry as it powers through the cool season, and keep the root zone evenly moist. Water roughly every 3 to 7 days, bumping it up when it turns dry, and aim at the base rather than the foliage to lock mold out.
Soil
Drop stock into fertile, well-drained soil, loam, sand, or clay charged with organic matter. It loves a pH of 6.0 to 8.0, so push slightly alkaline over acidic, because sour ground drags it down.
Temperature
Cool weather is where stock comes alive. It powers through light frost and peaks in the chill of spring or fall, running strong across about 28°F to 81°F (-2°C to 27°C), then dropping off quick once heat blows past the top of that range.
Humidity
Everyday outdoor humidity is a non-issue, so skip the numbers. Airflow is what counts, because jam stock together in damp weather and white mold jumps right in.
Feeding
Dig a balanced, all-purpose fertilizer into the bed at planting, then feed again about monthly while it grows hard. That steady fuel keeps fresh spikes firing without bulking up soft, floppy growth.
Pruning
Stock keeps pruning simple. Pinch or snip spent spikes to keep it sharp, and cut stems for the vase while they are fresh. Grown as a short annual, it asks for nothing else.
Size & spacing
Plants climb 1 to 3 feet (30 to 91 cm) tall and fan out about 9 to 18 inches (23 to 46 cm). Give each that space so air rips right through and mold never gets a grip.
When to plant
Stock lives on cool weather, so timing is where the fun starts. Fire up seed indoors in late winter, push the young plants outside in early spring while it stays cold, and they burst into bloom from late spring into early summer, wrapping up before the heat crashes the party.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: 6 to 8 weeks before the last spring frost; seed germinates in 7 to 14 days at 65 to 75°F (18 to 24°C)
- Plant: Transplant in early spring while weather is still cool; plants tolerate light frost. In mild-winter regions plant in fall or late winter.
- Harvest: Blooms May through July under cool conditions; cool exposure near 50 to 55°F (10 to 13°C) is needed to trigger flowering
Hardiness
USDA hardiness zones: 6–10
Temperature: down to -23°C
Troubleshooting
Stock is a strong grower, but two things trip it up: soggy, crowded plantings that rot, and weather that swings too warm for a cool-season flower. Spot the early signs and you can jump on the spacing, add support, or reset the timing before a planting slips away.
White mold storming the stems
This is white mold, the fungus Sclerotinia, and it charges in during the mild, wet, humid weather stock grows through. Yank and bin every plant wearing that cottony fuzz and water-soaked rot before it spreads. Then spread the survivors out, water low at the base, and get the air moving so the spores never grab a damp foothold.
Fix:
- Remove and discard affected plants
- Improve air circulation by proper spacing
- Avoid overhead watering and excess moisture
Plants crashing as the heat climbs
Stock is a cool-season flower, so heat pulls the plug. Past 80°F (27°C) the blooms quit and the plants nosedive fast, and a heat-hit planting is done for. Timing wins here, so run it through spring or fall and cut your flowers before the hot weather muscles in.
Fix:
- Grow as a cool-season crop and harvest before summer heat
- Time plantings for spring or fall cool periods
All leaves, zero flower spikes
When stock piles on green growth but launches no spikes, it skipped the cool spell that triggers bloom. Young plants crave a stretch near 50°F to 55°F (10°C to 13°C) while they are small. Hand them that cool conditioning at the right leaf stage, or grab early varieties that flower on a shorter cool window.
Fix:
- Expose young plants to cool temperatures near 50 to 55°F (10 to 13°C)
- Choose early varieties for short cool windows
Stems keeling over after transplant
Good news, this is just lodging, not disease. Those tall, top-heavy spikes tip or drop the second wind or a heavy watering shoves them. Lay horizontal netting at planting and give each plant elbow room, and the stems rocket up straight through the mesh.
Fix:
- Install a layer of horizontal support netting
- Provide even moisture and avoid overcrowding
Toxicity
Here is a great reason to plant stock everywhere: it is completely safe. The ASPCA files it among the non-toxic flowers, so cats, dogs, and the rest of the garden crew are in no danger, and the scented blooms are even edible. Go ahead and plant it right where pets and kids play.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Great around cats. The ASPCA lists stock as a non-toxic flower, so a curious nibble does zero harm.
Dogs None
Dogs are in the clear too. Stock packs no known toxin, though a dog that inhales a big pile of any plant might get a quick upset stomach.
Horses Safe
Horses can graze right beside stock, since it holds nothing that would hurt them.
Rabbits Safe
Rabbits are totally fine with stock, its leaves and flowers harmless if one takes a browse.
Livestock Safe
Cattle, goats, and sheep face zero risk from stock growing nearby.
Birds Safe
Birds can peck the plant or its seeds with no harm at all.
People Safe
Stock is safe for people, and its sweetly scented flowers even work as an edible garnish.
Varieties
Stock rolls out in a handful of strains, split mainly by how fast they bloom and how much cold they shrug off. These three are the ones to grab first.
Harmony Series
This series, loaded with Harmony Cherry Blossom and Harmony Purple, was bred to power through warmer climates like Florida.
Brompton Stock
A biennial-type strain gardeners overwinter to unleash a big flush of bloom the following spring.
Ten Weeks Stock
A speedy annual that nails its name, flowering roughly ten weeks after you sow it.
How to propagate
Stock takes off from seed, and getting it to sprout is the easy part. The real payoff comes from nailing the cool spell that flips a leafy plant into a flowering machine.
SeedModerate
Sow indoors 6 to 8 weeks before the last frost, or in seedling trays for transplanting; germinates in 7 to 14 days at 65 to 75°F (18 to 24°C) · 30 to 50 days to reach transplant size
Stock rockets up from seed. Start it indoors 6 to 8 weeks before your last frost, and it sprouts in 7 to 14 days at 65°F to 75°F (18°C to 24°C), then needs another 30 to 50 days to hit transplant size. Sow a fresh batch every couple of weeks to keep the bloom rolling all season, and give the young plants a cool spell so they flower.
Myths
Stock flowers are toxic and risky to keep around cats and dogs.
Not a chance. The ASPCA lists stock (Matthiola incana) among its non-toxic flowers, the ones that ship safely in bouquets. It will not poison cats or dogs, so grow it, cut it, and haul it indoors freely.
Feed stock enough sun and it flowers in any season.
Sun alone will not fire it up. Stock is a cool-season plant that needs a cool spell to set flowers, and it falls apart once heat pushes past about 80°F (27°C). Run it in spring or fall and skip the summer heat.