Shallot

Quick facts

Category

roots bulbs

Difficulty

beginner

Days to harvest

90 to 120 days

Harvest type

single harvest then replant

Spacing

15 cm between plants

Environment

Temperature

7–24°C

pH

6 to 7

EC (hydroponic)

1.4 to 1.8 mS/cm

Daily light

15 to 22 mol/m²/day

Climate and zones

USDA zones

4 to 10 (winter low around -34°C or warmer)

Frost tolerance

frost hardy (handles regular frost)

Season

cool (spring and fall crops)

Viable growing environments:

• outdoor year-round (in zone)
• outdoor in growing season (annual)
• unheated greenhouse / hoop house
• indoor (heated home)

USDA zone bounds reflect outdoor year-round survival. Anywhere outside the bounded zone range, this crop still grows as an annual in the warm months (outdoor_seasonal), under cover (greenhouse), or indoors under lights.

Growing systems

Shallot works in:

• media bed (ebb and flow)
• wicking bed
• soil bed

Growing media

The substrate the roots sit in. Choice depends on the system (clay pebbles don't fit NFT channels; rockwool isn't used in media beds) and the crop (shallot works in the media listed below).

Bacterial surface area matters for aquaponics: clay pebbles, lava rock, and pumice double as biofilter substrate. Low-surface media (rockwool, perlite, pea gravel) work in hydroponics but need a separate biofilter in aquaponics.

Nutrient demand by stage

NPK ratios are relative weights at each growth stage; the nutrient mix calculator scales them to absolute grams or ml. EC targets shift through the plant's life: seedlings need a much lighter solution than fruiting adults.

Companion-growing notes

• Heavy uptake of phosphorus. Co-grown crops with the same demand will end up deficient even at "correct" EC. Plan around this in shared reservoirs.
• Releases compounds through the roots that can mildly inhibit other crops in the same reservoir or bed. The effect is usually subtle but worth knowing if neighbors look stunted.

Aquaponics suitability

Compatible with typical aquaponics nutrient profiles. Fish waste provides enough nitrogen for healthy growth; supplemental potassium, calcium, and iron may still be needed depending on fish stocking density.

Care notes

A moderate-difficulty allium for media beds or containers (10 cm depth). EC 1.5-2.5 mS/cm. pH 6.0-7.0. Temperature: 12–25°C (cool to moderate). Moderate light (DLI 14-20 mol/m2/day). Plant sets (small bulbs) 2–3 cm deep in early spring or fall. Each set produces a cluster of 3-8 new bulbs over 90-120 days. Harvest when tops fall over and begin drying. Cure in a warm, dry, ventilated area for 2-3 weeks. Properly cured shallots store for 3-6 months at room temperature. Green shallot tops are edible during growth (use like green onions). For French cooking, the investment in growing shallots pays off: they're expensive at retail ($8-15/kg) and the quality of fresh, homegrown shallots is noticeably better than the often-sprouting imported product.

Further reading

• Best crops for hydroponic beginners
• The Kratky method: grow lettuce with zero electricity