GrowingHQ
VegetablebrassicaSome care needed

Broccoli

Brassica oleracea

Two crops under one name, and choosing between them is the whole decision. Calabrese is a summer crop giving one head and some side shoots from a spring sowing. Purple sprouting broccoli occupies the same ground from spring until the following March and then crops in the hungry gap, when almost nothing else is ready — which is what makes it worth the space.

Position
Full sun or Partial shade
Water
moderate demand
Drainage
Moisture-retentive
Grows to
60–90 cm × 45–60 cm
Hardiness
H5
Harvest
July to April
Difficulty
Some care needed

Described view

A calabrese plant with a tight dark green central head surrounded by blue-green leaves, ready to cut

August

Harvest

Broccoli’s year

Resolved for United Kingdom (general). Every window is stored against a climate event rather than a date, so a late frost pocket runs later than the band shows. What else August calls for.

ActivityJFMAMJJASOND
Sow under coverMarch. April.
Sow outdoorsApril. May. June.
Plant outMay. June. July.
HarvestFebruary. March. April. July. August. September. October.

Names that cause confusion

broccoli — Two quite different crops share the name. Calabrese produces one large green head in the same summer it is sown. Purple sprouting broccoli is sown in spring, stands the winter, and crops in shoots the following March — a fourteen-month occupation of ground.

Timing that travels

The band above resolves this plant's windows into months for one region. These are the windows themselves, stored against a climate event rather than a date — which is the form that survives being carried to a colder garden, a frost pocket, or next year.

  • Sow under cover2–6 weeks before your last spring frost
    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Broccoli — sowing

    Checked 2026-08-13

    Module-raised, which is the usual approach: it gets past the vulnerable seedling stage under cover.

  • Plant out2–10 weeks after your last spring frost
    source

    Sourced guidancehigh confidence

    • Royal Horticultural Society: Broccoli — planting out

    Checked 2026-08-13

    Plant firmly. A brassica that rocks in the wind never makes a decent head.

Conditions it needs

Light
Full sun, Partial shade
Direct sun
5 hours a day or more
Frost
HardySourced guidanceDepends on conditions
Hardiness rating
H5 (RHS)
Grows best at
15–20 °C
Germinates at
7–30 °C
Soil
Loam, Clay, Silt
Soil pH
6.5–7.5
Drainage
Moisture-retentive
Water needs
moderate
Drought
poor tolerance
Waterlogging
moderate tolerance
Heat
poor toleranceHorticultural consensusDepends on conditions
Wind and exposure
moderate tolerance
Where these figures come from
LightSourced guidancehigh confidence
  • Royal Horticultural Society: Grow your own: broccoli

Checked 2026-08-13

Direct sunHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

FrostSourced guidanceDepends on conditionshigh confidence

Applies when: Sprouting broccoli is very hardy and needs the winter. Calabrese is a summer crop and is finished before frost matters.

  • Royal Horticultural Society: Broccoli — hardiness

Checked 2026-08-13

Hardiness ratingSourced guidancehigh confidence
  • Royal Horticultural Society: RHS hardiness ratings

Checked 2026-08-13

Grows best atHorticultural consensusmoderate confidence
  • University of Minnesota Extension — University of Minnesota: Growing broccoli

Checked 2026-08-13

Germinates atSourced guidancehigh confidence
  • OSU Extension Service — Oregon State University: Vegetable seed germination temperatures

Checked 2026-08-13

SoilSourced guidancehigh confidence

Firm, well-consolidated soil. Brassicas do badly in loose fluffy ground.

  • Royal Horticultural Society: Brassicas — soil

Checked 2026-08-13

Soil pHSourced guidancehigh confidence

The alkaline end matters here: it suppresses clubroot as well as suiting the crop.

  • Royal Horticultural Society: Brassicas — soil pH

Checked 2026-08-13

DrainageHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Water needsHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

DroughtHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

WaterloggingHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

HeatHorticultural consensusDepends on conditionsmoderate confidence

Applies when: Heat makes calabrese heads open into flower prematurely and turns the buds yellow.

  • Home and Garden Information Center — Clemson Cooperative Extension: Broccoli — culture

Checked 2026-08-13

Wind and exposureHorticultural consensusmoderate confidence

Overwintering sprouting broccoli is tall and top-heavy and needs firming or staking.

No external citation — see the evidence type above.

Checked 2026-08-13

On your soil

Computed by comparing this plant's recorded requirements against each soil's recorded characteristics. A recorded horticultural fact overrides the comparison where GrowingHQ holds one.

SoilVerdictWhy
Heavy clayPrefers this soilHeavy clay suits Broccoli as it stands: The pH suits it: it wants 6.5 to 7.5, and this soil is in that range. Clay is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
SandyWorks, with one conditionBroccoli will crop on sandy, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Chalky and alkalineWorks, with one conditionBroccoli will crop on chalky and alkaline, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
LoamPrefers this soilLoam suits Broccoli as it stands: The pH suits it: it wants 6.5 to 7.5, and this soil is in that range. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
SiltyPrefers this soilSilty suits Broccoli as it stands: The pH suits it: it wants 6.5 to 7.5, and this soil is in that range. Silt is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
Peaty and acidGrows well hereBroccoli grows perfectly well on peaty and acid without special measures, though it is not the soil it would choose.
Shallow over rockWorks, with one conditionBroccoli will crop on shallow over rock, but one thing has to be dealt with first. It has little drought tolerance and this soil dries out fast — it will check and bolt in the first dry spell without watering.Water and mulch will carry it through. On this soil the watering is not optional in a dry spell, which is the difference between a crop and a failure.
Made ground and urban soilGrows well hereBroccoli grows perfectly well on made ground and urban soil without special measures, though it is not the soil it would choose.

Not sure which you have? Four hand tests will settle it.

Space and spacing

Mature height
60–90 cm
Mature spread
45–60 cm
Rooting depth
45 cm
Spacing
30–45 cm apartSourced guidanceDepends on conditions
Row spacing
45–60 cm
Where these figures come from
Mature heightHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Mature spreadHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Rooting depthHorticultural consensusmoderate confidence
  • USU Extension — Utah State University: Vegetable rooting depths

Checked 2026-08-13

SpacingSourced guidanceDepends on conditionshigh confidence

Applies when: About 30 cm for calabrese, 45–60 cm for sprouting broccoli, which makes a much larger plant.

  • Royal Horticultural Society: Broccoli — spacing

Checked 2026-08-13

Row spacingSourced guidancehigh confidence
  • Royal Horticultural Society: Broccoli — spacing

Checked 2026-08-13

How far apart to plant broccoliThree broccoli plants drawn in a row at their recorded spacing of 30–45 cm between plants, with a second row 45–60 cm away. The spacing is drawn to scale against a one metre rule; the plants themselves are symbols rather than scale drawings, so the distance between them is the part to read.30–45 cm45–60 cm between rowsone metre
Measured centre to centre. Plants set closer than this compete for light and water long before they look crowded, and the crowding cannot be undone once they are in.

In a container

Minimum volume
20 litres or more
Minimum depth
30 cm
Where the container figures come from
Minimum volumeSourced guidancehigh confidence
  • Royal Horticultural Society: Brassicas in containers

Checked 2026-08-13

Minimum depthHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Calabrese in a large pot is realistic; sprouting broccoli occupies it for over a year and is not.

Where and how you can grow it

Each way of growing is assessed separately, and “not assessed” is a real answer rather than a gap we have filled in with a guess.

MethodSuitabilityWhat it needs
Open groundWell suited
source

Sourced guidancehigh confidence

  • Royal Horticultural Society: Broccoli

Checked 2026-08-13

Firm soil; Netting against pigeons and caterpillars
Traditional dug bedWell suited
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Raised bedWell suited
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Firm the soil before planting
PolytunnelWell suited
source

Sourced guidancemoderate confidence

  • Agriculture and Horticulture Development Board — AHDB: Brassicas under protection

Checked 2026-08-13

Chiefly for raising transplants and for early calabrese.
GreenhouseWell suited
source

Sourced guidancemoderate confidence

  • Agriculture and Horticulture Development Board — AHDB: Brassicas under protection

Checked 2026-08-13

ContainerWorkable
Horticultural consensusDepends on conditionsmoderate confidence

Applies when: Calabrese only. Sprouting broccoli occupies the container for fourteen months.

  • Royal Horticultural Society: Brassicas in containers

Checked 2026-08-13

HydroponicsMarginal
source

GrowingHQ editorial positionmoderate confidence

Occupancy again, though the sprouting types come closer to justifying it than any other brassica because they are cut repeatedly over weeks rather than once.

  • GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

WindowsillNot suitable
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Growing it

  • TransplantingPlant out firmly, burying the stem up to the lowest leaves, and water in well. Brassicas need firm anchorage: press the soil down around the stem afterwards and pull a leaf — if it tears rather than lifting the plant, it is firm enough.
  • ProtectionNet from planting until harvest. Pigeons strip overwintering brassicas in a single visit and cabbage white caterpillars will do the rest in summer.
  • HarvestingCut the central head of calabrese while the buds are still tight, and the plant will produce smaller side shoots for several weeks afterwards. Waiting for the head to grow larger usually means waiting for it to open into flower.
  • WateringKeep the soil evenly moist. A check from dryness makes calabrese bolt straight to flower and produce a head the size of a coin, and it cannot be reversed once it has started. Water thoroughly every ten days or so in dry weather rather than lightly and often.
  • FeedingCompost dug in before planting, and a nitrogen-rich feed once the plants are growing away. Purple sprouting kinds stand all winter and benefit from a top dressing in late winter as they start into growth again.
Where this guidance comes from
TransplantingSourced guidancehigh confidence
  • Royal Horticultural Society: Brassicas — planting

Checked 2026-08-13

ProtectionSourced guidancehigh confidence
  • Royal Horticultural Society: Brassicas — protection

Checked 2026-08-13

HarvestingSourced guidancehigh confidence
  • Royal Horticultural Society: Calabrese — harvesting

Checked 2026-08-13

WateringSourced guidancehigh confidence
  • Royal Horticultural Society: Broccoli — watering

Checked 2026-08-13

FeedingSourced guidancemoderate confidence
  • Royal Horticultural Society: Broccoli — feeding

Checked 2026-08-13

Is it worth putting under cover?

Whether it will grow there is on the methods table above. This is whether the space is well spent, which is a different question and usually the one being asked.

StructureWhat protection is worthWhat decides it
GreenhouseNo real benefit
source

GrowingHQ editorial positionmoderate confidence

What protection is worth for this crop, judged against the same standard as every other record in this file.

  • GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

Occupies protected ground for months to produce something that grows perfectly well outdoors. The cost is not the crop, it is everything that could have been there instead.
PolytunnelNo real benefit
source

GrowingHQ editorial positionmoderate confidence

What protection is worth for this crop, judged against the same standard as every other record in this file.

  • GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

Occupies protected ground for months to produce something that grows perfectly well outdoors. The cost is not the crop, it is everything that could have been there instead.

Growing it without soil

Nearly anything can be grown in a soilless system by somebody with enough equipment. The useful question is whether it is worth it, in which technique, and what goes wrong.

Not worth it

It can be made to grow, but a soilless system is the wrong tool — usually because of rooting volume, running cost, or a result no better than a pot of compost.

source

GrowingHQ editorial positionmoderate confidence

Occupancy again, though the sprouting types come closer to justifying it than any other brassica because they are cut repeatedly over weeks rather than once.

  • GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

Sprouting broccoli is the near miss. Calabrese, cut once, is not close.

Techniques that suit it

  • Drip-fed mediumSolution is dripped into an inert medium around each plant. The most forgiving technique and the one that suits large, long-season, heavy crops.
  • Ebb and flowA bed of inert medium floods and drains on a timer. The medium holds moisture between floods, which makes it far more tolerant of interruption than NFT.
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Root space
Substantial.
pH band
5.5–6.5
Where these figures come from
Root spaceHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

pH bandSourced guidancehigh confidence

Outside roughly this band, individual nutrients become unavailable even when they are present in the solution — which is why a crop can starve in a full reservoir.

  • Purdue Extension — Purdue University: Hydroponic solution management — pH

Checked 2026-08-13

No nutrient recipes here

GrowingHQ records pH bands, which are measurable properties of nutrient availability, and deliberately records no EC or PPM targets and no mixing instructions. Published targets vary by cultivar, growth stage, water source and technique, and the figures that apply to your system are on the product you bought.

Harvesting

Time from sowing or planting: 12–16 weeks
Sourced guidanceDepends on conditionshigh confidence

Applies when: Calabrese from sowing. Sprouting broccoli takes closer to 44 weeks.

  • Royal Horticultural Society: Calabrese — timing

Checked 2026-08-13

  • When it is readyCut while the flower buds are tight and dark. Any yellow showing means flowers are opening and the head is past its best.
  • How to pick itCut the head with a sharp knife, leaving the plant in place for side shoots.
  • Keeping itA few days in a refrigerator; freezes well after blanching.
Where the harvest guidance comes from
When it is readySourced guidancehigh confidence
  • Royal Horticultural Society: Broccoli — harvesting

Checked 2026-08-13

How to pick itHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Keeping itHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Keep picking

Regular picking keeps this plant producing. Fruit or leaves left to mature signal it to slow down or stop.

What goes wrong

ProblemHow oftenNotes
Flea beetlecommon
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Cabbage root flycommon
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Transplants are the vulnerable stage; a collar or mesh at planting is the control.
Cabbage white caterpillarscommon
source

Sourced guidancehigh confidence

  • Royal Horticultural Society: Cabbage caterpillars

Checked 2026-08-13

Clubrootoccasional
source

Sourced guidancehigh confidence

  • Royal Horticultural Society: Clubroot

Checked 2026-08-13

Slugs and snailscommon
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

On young transplants.
Aphidsoccasional
source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Mealy cabbage aphid, which hides in the growing point.

Start from what you can see

Grown with, grown after, grown instead

Every relationship states its mechanism. A pairing nobody can explain is a pairing nobody has checked, and it does not go in.

  • Same rotation groupCabbage
    The same species, Brassica oleracea, sharing clubroot, cabbage root fly and every brassica pest. They belong in one rotation group and following one with the other defeats the rotation entirely.
    source

    Sourced guidancehigh confidence

    • GRIN Taxonomy — United States Department of Agriculture, Agricultural Research Service: Brassica oleracea cultivar groups

    Checked 2026-08-13

  • Closely relatedKale
    Another cultivar group of Brassica oleracea, bred for leaves rather than flower buds. Soil, spacing and protection requirements are effectively identical.
    source

    Sourced guidancehigh confidence

    • GRIN Taxonomy — United States Department of Agriculture, Agricultural Research Service: Brassica oleracea cultivar groups

    Checked 2026-08-13

Safety and edibility

  • Which parts are edibleThe flower heads, the young leaves and the tender stems are all edible. The leaves of calabrese are perfectly good greens and are usually discarded.
    source

    Horticultural consensusmoderate confidence

    • Royal Horticultural Society: Broccoli

    Checked 2026-08-13

    Use the leaves as well as the heads.

Sources for this page

Agriculture and Horticulture Development Board · GrowingHQ editorial synthesis · Home and Garden Information Center · OSU Extension Service · Royal Horticultural Society · University of Minnesota Extension · USU Extension

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-13.

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