Can you grow stock flowers hydroponically? Yes. Stock flower hydroponics works well because Matthiola incana is a cool-season cut flower grown from seed at close 4–6 inch (10–15 cm) spacing. Johnny’s Selected Seeds gives germination in 7–14 days at 65–75°F (18–24°C), and Cornell notes plants need cool 50–55°F (10–13°C) temperatures to initiate flowers. Grow them cool, bright and supported.
Key takeaway: Stock is a fragrant brassica-family cut flower. NC State says plants decline when temperatures stay above 80°F (27°C) and suffer in hot nights, so stock flower hydroponics suits cool rooms, basements, greenhouses and winter growing. Expect a mix of double and single flowers unless you buy selected seed.
| Factor | What sources report | Source |
|---|---|---|
| Botanical name | Matthiola incana (Brassicaceae) | NC State Extension |
| Germination | 7–14 days at 65–75°F (18–24°C) | Johnny’s Selected Seeds |
| Cold to flower | 50–55°F (10–13°C) for 2–3+ weeks | Cornell High Tunnels |
| Heat limit | Declines above 80°F (27°C) | NC State Extension |
| Spacing | 4–6 inches (10–15 cm) | Johnny’s; Cornell |
| Harvest | When 1/3–1/2 of florets are open | Johnny’s Selected Seeds |
What Is Stock Flower?
Stock is Matthiola incana, a cool-season flowering plant in the mustard family. NC State Extension describes it as an upright plant reaching about 3 feet (91 cm) with hairy gray-green leaves and clove-scented flowers. Most modern stock varieties are hybrids, available in pink, lavender, purple, white, yellow and red.
Mississippi State University Extension notes double flowers about 1¼ inches (3 cm) wide clustered along 6–8 inches (15–20 cm) of stem, with cut stems of 12–28 inches (30–71 cm). Stock is one of the most fragrant hydroponic flowers you can grow, and Johnny’s also lists it as an edible flower.
Why Grow Stock Flower Hydroponically?
Stock flower hydroponics lets you grow a cool-season crop in a controlled space where you can hold temperatures down. Stock is sensitive to heat, so an indoor or greenhouse system in fall, winter and early spring gives long, straight, fragrant stems that are hard to produce outdoors in warm climates.
- Temperature control: keep plants cool for flowering.
- Dense planting: 4–6 inch (10–15 cm) spacing fits trays and troughs.
- Fast succession: sow every two weeks for steady harvests.
- Clean stems: no soil on cut flowers.
How Do You Start Stock Flower Hydroponics From Seed?
Start stock flower hydroponics by sowing seed 1/4 inch (6 mm) deep in plugs 5–6 weeks before transplanting, as Johnny’s recommends. Cover seed lightly with fine media or vermiculite. Keep plugs at 65–75°F (18–24°C) until seedlings emerge, then give long days and cooler temperatures.
- Sow 1–2 seeds per rockwool or coco plug.
- Cover lightly so some light reaches the seed.
- Keep plugs at 65–75°F (18–24°C) until emergence.
- Optional: chill seedlings at 40–45°F (4–7°C) for 3–4 days to sort doubles.
- Transplant into the system after 5–6 weeks.
Johnny’s explains that chilled seedlings with lighter green, oval cotyledons usually produce double flowers, but selection is difficult and single flowers are still marketable. Our guide to seedling heat mats and humidity domes helps you get even germination.
What Temperature and Light Does Stock Need?
Stock needs cool temperatures to bloom. Cornell’s high tunnel guide says plants require 50–55°F (10–13°C) to initiate flowers, for about 2 weeks in early varieties and 3 weeks or more in late ones. Mississippi State says stock prefers full sun. Indoors, give bright LEDs and keep nights cool.
| Setting | Starting point | Basis |
|---|---|---|
| Germination | 65–75°F (18–24°C) | Johnny’s; Mississippi State |
| Flower initiation | 50–55°F (10–13°C) | Cornell High Tunnels |
| Upper limit | Below about 80°F (27°C) | NC State Extension |
| Light | Full sun or bright LED | Mississippi State; NC State |
Use our guide to EC and TDS in hydroponics to keep feeding steady through the crop.
What Is the Best System for Stock Flower Hydroponics?
The best system for stock flower hydroponics is drip or ebb and flow into a well-drained substrate, with horizontal netting for support. Johnny’s lists well-drained soil and says a horizontal trellis is necessary when temperatures stay above 60°F (16°C). Cornell notes plants tend to lodge after transplanting, so add one layer of netting early.
| System | Fit for stock | Note |
|---|---|---|
| Drip into coco trough | Excellent | Dense 4–6 inch (10–15 cm) spacing |
| Ebb and flow tray | Good | Let media drain well |
| Dutch bucket | Good | Several plants per bucket |
| Deep water culture | Fair | Needs support netting |
For bucket systems, read Dutch bucket hydroponics for beginners.
When Do You Harvest Stock Flowers?
Harvest stock flowers when one-third to one-half of the florets on a stem are open, as Johnny’s advises. Cut stems in the cool part of the day and place them straight into water. Johnny’s gives a storage temperature of 36–41°F (2–5°C) and a vase life of 5–10 days.
Johnny’s says not to pinch stock plants, and to succession-plant every 2 weeks for multiple harvests. Each columnar plant gives one main stem, so steady sowing keeps flowers coming.
What Problems Affect Stock Flower Hydroponics?
The main problems in stock flower hydroponics are heat, lodging and pests. Plants that stay too warm may fail to flower; Cornell notes late varieties can produce only leaves without enough cold. Because stock is a brassica, Johnny’s warns about flea beetles.
- No flowers: plants did not get enough cool temperatures.
- Bent stems: add netting; store stems upright.
- Small holes in leaves: check for flea beetles.
- Short stems: heat sped up flowering; grow cooler.
How Many Stems Does Stock Flower Hydroponics Produce?
Stock flower hydroponics usually gives one main stem per plant, because Johnny’s advises against pinching. That is why growers plant densely at 4–6 inches (10–15 cm) and sow new trays every two weeks. Mississippi State notes spray-type and columnar types differ, so read seed descriptions before buying if you want branching stems.
A small home system with 20–30 plants can supply fragrant bouquets for several weeks when you stagger sowings through the cool season.
FAQ About Stock Flower Hydroponics
Is stock flower hydroponics good for beginners?
Yes, if you can keep the room cool. Stock germinates readily and grows densely.
Why is my stock not flowering?
It likely missed the 50–55°F (10–13°C) cold period Cornell describes.
Should I pinch stock plants?
Johnny’s says do not pinch; grow them as single stems.
How long do stock cut flowers last?
Johnny’s gives a vase life of 5–10 days.
Can I grow stock flower hydroponics indoors in summer?
Only in a cool room. Stock declines above about 80°F (27°C).
Sources
- NC State Extension — Matthiola incana
- Johnny’s Selected Seeds — Stock key growing information
- Cornell High Tunnels — Stock
- Mississippi State University Extension — Stock for the farmer florist
- Photo credits (Wikimedia Commons, edited with titles): Matthiola incana Harmony Light Rose 1zz by Photo by David J. Stang (CC BY-SA 4.0); Matthiola incana Harmony Light Rose 3zz by Photo by David J. Stang (CC BY-SA 4.0)