VegetablealliumStraightforward

Shallot

Allium cepa var. aggregatum

An onion that multiplies: one bulb planted produces a clump of six to twelve. They store better than onions, are milder in cooking, and are planted early enough to be one of the first things in the ground each year.

Position: Full sun
Water: low demand
Drainage: Free-draining
Grows to: 30–45 cm × 15–20 cm
Hardiness: H5
Harvest: July and August
Difficulty: Straightforward

August

Harvest

Shallot’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.

Activity	J	F	M	A	M	J	J	A	S	O	N	D
Plant	January.	February.	March.									December.
Harvest							July.	August.

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.

Conditions it needs

Light: Full sun
Frost: Very hardy
Hardiness rating: H5 (RHS)
Grows best at: 13–24 °C
Soil: Loam, Sandy
Soil pH: 6–7.5
Drainage: Free-draining
Water needs: low
Drought: moderate tolerance
Waterlogging: poor tolerance
Heat: good tolerance
Wind and exposure: good tolerance

Where these figures come from

LightSourced guidancemoderate confidence

Royal Horticultural Society: Shallot — position

Checked 2026-08-13

FrostSourced guidancehigh confidence

Royal Horticultural Society: Shallot — hardiness

Checked 2026-08-13

Hardiness ratingSourced guidancemoderate confidence

Royal Horticultural Society: RHS hardiness ratings

Checked 2026-08-13

Grows best atSourced guidancemoderate confidence

Royal Horticultural Society: Shallot — temperature

Checked 2026-08-13

SoilSourced guidancemoderate confidence

Royal Horticultural Society: Shallot — soil

Checked 2026-08-13

Soil pHSourced guidancemoderate confidence

Plant Finder — Missouri Botanical Garden: Allium cepa — culture

Checked 2026-08-13

DrainageSourced guidancemoderate confidence

Royal Horticultural Society: Shallot — soil

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

Bulbs rot in wet ground, which is the main risk on clay.

No external citation — see the evidence type above.

Checked 2026-08-13

HeatHorticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Wind and exposureHorticultural consensusmoderate confidence

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.

Soil	Verdict	Why
Heavy clay	Works, with one condition	Shallot will crop on heavy clay, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Sandy	Prefers this soil	Sandy suits Shallot as it stands: The pH suits it: it wants 6 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. Sandy soil is among the soils it is recorded as suiting.
Chalky and alkaline	Grows well here	Shallot grows perfectly well on chalky and alkaline without special measures, though it is not the soil it would choose.
Loam	Prefers this soil	Loam suits Shallot as it stands: The pH suits it: it wants 6 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting. The soil holds moisture, which saves a great deal of watering.
Silty	Prefers this soil	Silty suits Shallot as it stands: The pH suits it: it wants 6 to 7.5, and this soil is in that range. The free drainage is exactly what it wants. The soil holds moisture, which saves a great deal of watering.
Peaty and acid	Works, with one condition	Shallot will crop on peaty and acid, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.
Shallow over rock	Prefers this soil	Shallow over rock suits Shallot as it stands: The free drainage is exactly what it wants. Loam is among the soils it is recorded as suiting.
Made ground and urban soil	Works, with one condition	Shallot will crop on made ground and urban soil, but one thing has to be dealt with first. It needs ground that drains, and this soil holds water. A plant that stays in the ground through winter with its roots in cold, saturated soil rots — which is what kills most of what fails on heavy ground, rather than the cold.Improve the drainage before planting — a raised bed, or bulky organic matter worked in over several seasons. Do not add sand to clay in small quantities; it makes the problem worse.

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

Space and spacing

Mature height: 30–45 cm
Mature spread: 15–20 cm
Rooting depth: 20 cm
Spacing: 15–20 cm apart

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: No external citation — see the evidence type above.
Checked 2026-08-13
SpacingSourced guidancemoderate confidence: Royal Horticultural Society: Shallot — spacing
Checked 2026-08-13

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: 10 litres or more
Minimum depth: 20 cm

Where the container figures come from

Minimum volumeHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13
Minimum depthHorticultural consensusmoderate confidence: No external citation — see the evidence type above.
Checked 2026-08-13

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.

Method	Suitability	What it needs
Open ground	Well suited source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13
Traditional dug bed	Well suited source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13
Raised bed	Well suited source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13
Container	Well suited source Sourced guidancemoderate confidence Royal Horticultural Society: Growing method suitability Checked 2026-08-13	10 litres; 20 cm deep
Hydroponics	Marginal source GrowingHQ editorial positionmoderate confidence The onion's argument exactly: a long season occupying lit space to produce something worth pence, and a bulb that needs to be dried and cured rather than harvested fresh. GrowingHQ editorial synthesis — GrowingHQ Checked 2026-08-13
Greenhouse	Marginal source Sourced guidancemoderate confidence Agriculture and Horticulture Development Board — AHDB: Alliums under protection Checked 2026-08-13
Polytunnel	Marginal source Sourced guidancemoderate confidence Agriculture and Horticulture Development Board — AHDB: Alliums under protection Checked 2026-08-13

Growing it

PlantingPush each set in so the tip is just visible, and firm the soil around it. Birds pull loose sets out, which is the commonest reason a row looks patchy a week after planting.
HarvestingStop watering once the foliage begins to yellow. Shallots lifted from wet ground do not dry properly and rot in store rather than keeping until spring.

Where this guidance comes from

PlantingSourced guidancehigh confidence: Royal Horticultural Society: Shallot — care
Checked 2026-08-13
HarvestingSourced guidancehigh confidence: Royal Horticultural Society: Shallot — care
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.

Structure	What protection is worth	What decides it
Greenhouse	No 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. Shallots are planted in the shortest days and lifted in midsummer, holding the ground through the whole protected season.
Polytunnel	No 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

The onion's argument exactly: a long season occupying lit space to produce something worth pence, and a bulb that needs to be dried and cured rather than harvested fresh.

GrowingHQ editorial synthesis — GrowingHQ

Checked 2026-08-13

Curing needs warm dry air for weeks after lifting, and a system supplies neither.

Techniques that suit it

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.
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.

source

Horticultural consensusmoderate confidence

No external citation — see the evidence type above.

Checked 2026-08-13

Root space: Moderate, for a very long time.
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

When it is readyReady when the foliage has yellowed and toppled and the clump has split into separate bulbs, usually in July or early August. Unlike onions, shallots are ready as a cluster rather than singly — lift the whole clump and separate it afterwards. Do not bend the tops over to hasten ripening; it damages the neck and shortens how long they keep.
How to pick itLoosen the clump with a fork and lift it whole. Spread the bulbs in a single layer somewhere warm, dry and airy for two to three weeks until the skins rustle and the necks are papery — this drying is what decides whether they keep until spring or rot by Christmas.
Keeping itDry the clumps thoroughly in an airy place for two or three weeks, then store somewhere cool and dry. Well-dried shallots keep until the following spring, which is longer than most onions.

Where the harvest guidance comes from

When it is readySourced guidancehigh confidence: Royal Horticultural Society: Shallots — harvesting
Checked 2026-08-13
How to pick itSourced guidancehigh confidence: Royal Horticultural Society: Shallots — harvesting
Checked 2026-08-13
Keeping itSourced guidancehigh confidence: Royal Horticultural Society: Shallot — storage
Checked 2026-08-13

What goes wrong

Problem	How often	Notes
Bulb ripening	common source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Ripening rather than a fault. The yellowing tops are the signal to stop watering and lift.
Allium white rot	occasional source Horticultural consensusmoderate confidence No external citation — see the evidence type above. Checked 2026-08-13	Persists in soil for up to twenty years, so a bed that has had it should not grow alliums again.

Sources for this page

Agriculture and Horticulture Development Board · GrowingHQ editorial synthesis · Plant Finder · Royal Horticultural Society

Each figure on this page carries its own citation, under the “where these figures come from” note in its section. Record last reviewed 2026-08-14.