Tomatillos

A simple description of tomatillos as green tomatoes in a husk is only partially accurate. Tomatillos are definitely enclosed in a papery husk, and are closely related to tomatoes in the nightshade (Solanaceae) family. But tomatillos are botanically identified as Physalis ixocarpa and tomatoes as Solanum lycopersicum—the two are quite different. Used in Mexican cooking, tomatillo fruits are sometimes called husk tomatoes and can be described as looking like Chinese lanterns.

Warm-Season Crop

Most tomatillos are pale to deep green in color although reddish purple varieties are available.
Start from seed indoors in March and transplant into the garden in 5-6 weeks when the chance of freeze has passed, usually early May in Sonoma County. Purchase seed or use seed from produce market fruits. Or purchase starts from a nursery for transplanting.
Plan on 90-100 days from germination to harvest.
Select a planting site with 6-8 hours of sunlight a day, in the ground or in 12-in. deep containers.

Growing Tomatillos

Plant a minimum of 2 tomatillos for cross-pollination needed to develop fruit. One plant may produce a few fruits but, for a sizeable crop, 2 or more are needed.
Depend on bees to carry pollen from one plant to another. Tomatillos do not cross with nearby tomatoes, only with another tomatillo.
Irrigate regularly, about 1 in. of water per week, more if needed in warmer microclimates and the hottest inland areas. Container-growing may require more irrigation than plants in the ground. After fruit has set, reduce watering frequency.
Feed plants regularly with a fertilizer high in potassium and phosphorus to aid fruit set.
Mulch soil with compost or other organic material to retain moisture.
Stake or trellis vine-like tomatillos to keep fruit off the ground. Stems grow 3-4 ft. long.
Tomatillos are susceptible to the same insects that plague tomatoes: aphids, cucumber beetles, potato beetles and other leaf-loving bugs. (See link below.)
Use drip irrigation to conserve water and monitor soil moisture regularly. Avoid water stress to prevent powdery mildew.

Harvesting

Harvest firm, bright green tomatillos that have a light-brown, mostly tight-fitting husk. Full-grown fruit is often only golf-ball size but may be smaller or larger; smaller fruit is often sweeter; slightly acidic flavor is preferred. Yellowing fruit is past ideal ripeness stage.
Store fresh tomatillos in a paper bag in the refrigerator with the husk still intact for three weeks to a month. Delay washing fruits until ready for use.
To keep tomatillos longer, remove husks, wash the fruits and freeze them. The outer tomatillo skin inside the husk is quite sticky but is removed with washing.
Use raw in salsas, guacamoles, and salads; diced and cooked in sauces, moles or stews.
Cooking enhances flavor and softens the skin; fruit collapses after a few minutes of cooking into a soupy consistency.

Additional Information

Sonoma County Master Gardener Vegetable Planting Summary
http://ipm.ucanr.edu/home-and-landscape/tomato/index.html

April 2022