Tomatillo / Mexican husk tomato (Physalis philadelphica) growing guide

Quick facts

Category: fruiting
Difficulty: intermediate
Days to harvest: 75 to 100 days
Harvest type: continuous production over weeks or months
Spacing: 90 cm between plants

Environment

Temperature: 18–30°C
pH: 6 to 7
EC (hydroponic): 2 to 3 mS/cm
Daily light: 22 to 30 mol/m²/day

Climate and zones

USDA zones: 5 to 11 (winter low around -29°C or warmer)
Frost tolerance: frost sensitive (dies at first frost)
Season: warm (summer crops, frost-sensitive)

Viable growing environments:

outdoor in growing season (annual)
unheated greenhouse / hoop house
heated greenhouse
indoor hydroponics under grow lights

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

Tomatillo works in:

drip / Dutch buckets
media bed (ebb and flow)
soil bed

Root mass is heavy - thin-channel systems (NFT, vertical towers) can't hold this crop mechanically, hence the system list above.

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 (tomatillo works in the media listed below).

Medium	pH effect	Water retention	Bacterial surface
Expanded clay pebbles (LECA)	neutral / inert	low	high
Coco coir (Coconut coir)	slightly acidic	high	moderate
Perlite (Expanded volcanic glass)	neutral / inert	very low	low
Rockwool (Mineral wool)	alkaline until pre-soaked	very high	low
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	2	1	1	1.2
vegetative	3	1	2	2
flowering	1	2	3	2.4
fruiting	1	2	3	2.8

Companion-growing notes

Heavy uptake of potassium, calcium. Co-grown crops with the same demand will end up deficient even at "correct" EC. Plan around this in shared reservoirs.
High transpiration. Reservoir level will need regular top-ups during fruiting or flowering.

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 productive, easy hydroponic crop for Mexican cooking. DWC, Dutch bucket, or media bed systems. EC 1.5-2.5 mS/cm. pH 5.5-6.5. Temperature: 18–28°C (warm-season; more cold-tolerant than tomatoes). Moderate to high light (DLI 16-25 mol/m2/day). Plants are sprawling and benefit from caging or staking. From transplant to first harvest: 65-80 days. Plant at least two individuals (from different seed sources) for cross-pollination. Harvest when the husk splits and the fruit fills the husk completely. The fruit should be firm and bright green (not yellowing, which indicates overripeness). Each plant produces 30-60+ fruits. For salsa verde: husk the tomatillos, roast on a comal or under a broiler until charred and softened, blend with roasted serrano or jalapeno, onion, garlic, cilantro, salt, and lime juice. The tangy, bright flavor of fresh tomatillo salsa is incomparably better than jarred versions.

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
Toma Verde	open-pollinated	75	Standard green tomatillo, large 6 cm fruit, the variety most commercial salsa verde uses. Early and reliable.
Purple	open-pollinated	80	Purple skin, sweeter than green types when fully ripe; works fresh-eaten or in salsas. Smaller fruit (3-4 cm) but more productive per plant.
Pineapple	heirloom	75	Small yellow fruit (1-2 cm) with a sweet pineapple-like flavor. Closer to ground cherry in eating quality; works for fresh dessert use rather than salsas.