Peanut / Groundnut (Arachis hypogaea) growing guide

Quick facts

Category: fruiting
Difficulty: intermediate
Days to harvest: 120 to 150 days
Harvest type: single harvest then replant
Spacing: 20 cm between plants

Environment

Temperature: 18–32°C
pH: 5.5 to 7
EC (hydroponic): 1 to 1.6 mS/cm
Daily light: 18 to 26 mol/m²/day

Climate and zones

USDA zones: 6 to 11 (winter low around -23°C or warmer)
Frost tolerance: frost sensitive (dies at first frost)
Season: warm (summer crops, frost-sensitive)

Viable growing environments:

outdoor year-round (in zone)
outdoor in growing season (annual)

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

Peanut works in:

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 (peanut works in the media listed below).

Medium	pH effect	Water retention	Bacterial surface
Soil-based mix (Potting soil)	varies by source	high	high

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.

Stage	N	P	K	EC target (mS/cm)
seedling	1	1	1	0.7
vegetative	1	1	2	1.2
flowering	1	1	2	1.4
fruiting	1	1	2	1.4

Aquaponics suitability

Not recommended for pure aquaponics. Fish waste alone doesn't provide enough of the nutrients this crop demands (typically potassium, calcium, or boron). It can be grown in a hybrid system where the reservoir is supplemented with hydroponic-style nutrients, but expect to dose actively.

Care notes

An unusual hydroponic crop requiring deep media beds because the fruit develops underground. Media beds with 15 cm of loose substrate (perlite, sand, or coir) to accommodate the pegs pushing into the media. EC 1.0-2.0 mS/cm (light feeder). pH 6.0-7.0. Temperature: 22–32°C (warm-season; frost kills the plant). High light (DLI 18-25 mol/m2/day). From seed to harvest: 120-150 days. Direct seed into the media bed (peanuts don't transplant well). After flowering (small yellow flowers appear along the lower stems), the pegs push downward; ensure the media around the base of the plant is loose enough for peg penetration. As a legume, peanuts fix nitrogen through Bradyrhizobium root nodules. Harvest when the foliage yellows and the pods have developed their characteristic netted texture. Dig the entire plant carefully and cure the pods by drying in a warm, ventilated area for 1-2 weeks. Each plant produces 25-50 pods. A fun, educational crop for families, though the long season and space requirements make it impractical for commercial hydroponic production.

Notable varieties

A starting shortlist of cultivars worth knowing about. Not exhaustive: the seed catalogs list hundreds of named varieties. These are the ones home growers commonly choose between.

Cultivar	Type	Days	Notes
Runner (Georgia Green)	open-pollinated	140	The peanut-butter peanut, US Southeast commercial standard. Medium uniform kernels, prostrate growth habit covering 1 m diameter per plant. Georgia Green is the released cultivar that dominated production through the 1990s-2010s. Disease-resistant. Zones 7-10.
Virginia (Bailey, Wynne)	open-pollinated	150	Large kernels, the cocktail and in-shell roasted peanut. Bunch-type growth (more upright than Runner). Grown in the Virginia-Carolina belt. Higher market value, lower yield. Zones 7-10. Bailey is the modern disease-resistant standard.
Spanish (Tamspan, Pronto)	open-pollinated	120	Small reddish-skinned kernels with high oil content, used for peanut candy, salted snacks, and oil pressing. Earlier than Runner or Virginia, useful for short-season growing. Drought-tolerant. Zones 6-10.
Valencia (Tennessee Red)	open-pollinated	130	3-4 small light-tan kernels per pod with red papery skin. The in-shell roasted peanut at sporting events. Sweet flavor, less oil than other types. Bunch growth. Heritage and home-grower favorite. Zones 7-10.