Mustard
Brassica juncea
Brassicaceae · cabbage family
- Matures
- 35–45 days
- Harvest
- Over a period · Annual
- Sun
- 4–8 hrs
- Spacing
- 3–6 in
Planting window
When to sow, by microclimate — foggier blocks run a different calendar than sunnier ones.
| Jan | Feb | Mar | Apr | May | Jun | |
|---|---|---|---|---|---|---|
| Foggy | ● | ● | ● | ● | ● | ● |
| Sunny | ● | ● | ● | ● |
| Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|
| Foggy | ● | ● | ● | ● | ||
| Sunny | ● | ● |
Well-suitedMarginalNot suited
Sunlight
How well it does at each level of direct sun per day.
<2 hrsNot suited
2–4 hrsMarginal
4–6 hrsWell-suited
6–8 hrsWell-suited
8+ hrsMarginal
Well-suitedMarginalNot suited
Soil depth
Root room it needs — useful for sizing raised beds and containers.
6–10"Well-suited
10–15"Well-suited
15–18"Well-suited
18–24"Well-suited
Well-suitedMarginalNot suited
Spacing
Room each plant needs — along the row and between rows — for sizing beds.
- In-row
- 3–6 in
- Between rows
- 12–24 in
Growth habit
The shape it makes in the bed and how tall it gets — what tells you whether to give it a trellis, a stake, or just room.
- Habit
- Low mound
- Mature height
- 0.7–2 ft
Low and self-supporting — no staking needed.
How to start it
Sow it where it grows, or raise it under cover and set it out — and how far ahead to start the seedlings if it's the latter.
- Usually
- Direct-sow
- Start indoors
- 4 weeks ahead
Direct-sowWell-suited
TransplantWell-suited
Sown straight into the bed it will grow in.
Well-suitedMarginalNot suited
Getting started
How it goes in the ground — how deep to sow or set it, and the soil temperature it needs to wake up. The cold-soil floor is the real limiter for direct-sowing in a foggy SF spring.
- Started from
- From seed
- Ideal soil temp
- 45–85°F
- Sow depth
- 0.5 in
- Time to emerge
- 4–7 days
Germinates between 40–85°F; happiest around 45–85°F.
30°F110°F
IdealWorkable
Pests & diseases
What tends to trouble this crop — what it is, what you'll see, and what to do about it, least-toxic first.
USU: Most mustard is fast growing and is not susceptible to many production problems. Rotating locations from year to year helps control most diseases.
Pests4
Aphids
- What it is
- Aphids have soft pear-shaped bodies with long legs and antennae and may be green, yellow, brown, red, or black depending on the species and the plants they feed on. A few species appear waxy or woolly due to the secretion of a waxy white or gray substance over their body surface.
- What you'll see
- Low to moderate numbers of leaf-feeding aphids aren't usually damaging in gardens or on trees. However, large populations can turn leaves yellow and stunt shoots; aphids can also produce large quantities of a sticky exudate known as honeydew, which often turns black with the growth of a sooty mold fungus.
- What to do
- Before planting vegetables, check surrounding areas for sources of aphids and remove these sources. On the other hand, these aphid-infested weeds can sometimes provide an early source of aphid natural enemies.
Cabbage Worms and Loopers
- What you'll see
- Worms and loopers are light to dark green. Adult loopers are gray or brown moths while cabbage worms are white butterflies. Worms and loopers chew holes in leaves and hide in kale heads.
- What to do
- Control worms and loopers with appropriate insecticides or biological measures.
Slugs
- What you'll see
- Soft-bodied or shelled mollusks that chew holes in leaves.
- What to do
- Control with appropriate pesticides or traps. Avoid moist conditions that favor these pests.
Flea Beetles
- What it is
- Their small size, enlarged back legs, characteristic shot-hole damage, and habit of jumping when disturbed make flea beetles easy to identify. There are numerous flea beetle species.
- What you'll see
- Adults feed mostly on leaves, leaving tiny pits or small holes at their feeding sites. Flea beetles feeding together can cover leaves with bleached, pitted areas or ragged holes.
- What to do
- Remove debris in the fall to remove any overwintering beetles. Reflective mulches applied very soon after planting and before plants become infected can be helpful.
Sources
Every figure above is backed by these.
- UC Master Gardeners, San Mateo–SF Countiesbacks plantingWindow, startMethod · Foggy & Sunny calendars, Mustard row (from seed): foggy Jan-Oct; sunny Jan-Apr & Aug-Sep. Start method: Foggy & Sunny calendars, Mustard row: (S) sow seed only.
- UC Master Gardeners, Sonoma County (Planting Summary)backs daysToMaturity, inRowSpacing, rowSpacing, startMethod · Vegetable Planting Summary, Greens, assorted row (mustard greens fall under assorted greens): 35-45 days, 2-6 in in-row spacing. Between-row spacing 12-24 in (Greens, assorted row). Start method: Vegetable Planting Summary, Greens, assorted row: method D (usually direct-sown).
- Utah State University Extensionbacks inRowSpacing, plantingDepth · 'How to Grow Mustard in Your Garden' (USU Extension): 'spaced 3 inches between plants in the row' - the tight/baby-leaf floor; combined with Sonoma assorted greens (up to 6 in) gives 3-6 in. Planting depth 1/2 in: 'Seeds should be planted 1/2 inch deep.'
- UC Master Gardeners, Santa Clara County (Containers)backs soilDepth · No mustard row; assigned shallow-rooted (6-9 in) by parity with the other quick leafy greens listed under shallow-rooted (spinach, lettuces).
- Golden Gate Gardening (Pam Peirce)backs sunlight, lifecycle, harvestStyle · Mustard is a cool-season leafy green that tolerates part shade and bolts in heat, so full sun in sunnier spots is only marginal (8+ hrs = maybe). Habit and harvest: annual, over-a-period — from this source's entry for this crop.
- Cornell University Home Gardeningbacks germination · Cornell mustard greens: germination 45–85°F, as low as 40°F; emergence 4–7 days
- USDA GRIN Taxonomybacks botany
- UC Master Gardeners, Santa Clara Countybacks growthHabit · UC MG Santa Clara mustard-greens page, variety heights: 'Red Giant' and 'Spicy Green' grow '8 to 24 inches tall', 'Ruby Streaks' '6 to 12 inches tall'. A leafy rosette that bolts in heat, classified low-mound; height 8-24 in from the large-leaf mustard-green varieties.
- UC Master Gardeners, Santa Clara Countybacks startMethod · Start method: Planting chart: Mustard greens carry both rows; From seed to transplant 4 weeks.