Tomatillo Planting Calendar: Month-by-Month Guide

Tomatillos are productive, tangy fruits that benefit from careful timing and attention throughout the growing season. Over decades of growing tomatillos in Sonoma Valley, I’ve developed a month-by-month planting and care schedule that helps gardeners achieve vigorous plants and abundant fruit. This guide outlines the key tasks for each month to maximize yield and ensure healthy growth.

Table of Contents

January–February: Seed Starting Indoors

Start seeds 6–8 weeks before last expected frost.
Use seed trays or small pots with well-draining seed-starting mix.
Maintain warmth (70–75°F) and light (12–16 hours/day).

Experience Tip:
I keep seedlings under fluorescent lights indoors until they develop 2–3 true leaves before hardening off.

March: Continue Seedlings & Prepare Soil

Harden off seedlings gradually, exposing them to outdoor conditions for a few hours daily.
Prepare raised beds or garden rows with compost-enriched, loose soil.
Begin planning plant layout with 24–36 inches spacing between plants.

April: Transplant Outdoors

Wait until soil and air temperatures are consistently above 60°F.
Plant seedlings up to first set of true leaves.
Water thoroughly after transplanting and apply a light mulch to retain moisture.

Experience Tip:
I often transplant mid-April in Sonoma for steady growth and early fruit set.

May: Early Care and Growth

Remove damaged leaves and monitor for pests like aphids or flea beetles.
Begin staking or caging plants to support growing vines.
Fertilize lightly with a potassium-rich organic amendment once fruits begin forming.

June–July: Full Season Maintenance

Water deeply 1–2 times per week, adjusting for rainfall.
Continue mulching to retain soil moisture and suppress weeds.
Monitor for disease and remove any affected leaves promptly.

Experience Tip:
I focus on consistent care during the peak growing season; well-maintained plants set more fruit.

August: Fruit Development and Pollination

Encourage cross-pollination by planting at least two tomatillo plants together.
Trim excess foliage only if it shades fruit or restricts airflow.
Continue deep watering and mulch maintenance.

September: Harvest Begins

Harvest fruits when husks split and fruits feel firm.
Leave some fruits to mature fully for later harvest.
Continue watering to support ongoing production.

Experience Tip:
Regular harvesting encourages the plant to produce more fruit throughout late summer and early fall.

October–November: Late-Season Care

Remove old or diseased leaves.
Monitor plants for late-season pests and fungal issues.
Harvest remaining fruits before first frost in cooler regions.

December: Garden Cleanup

Remove spent vines and compost healthy plant material.
Plan next year’s planting schedule and rotate crops to prevent disease buildup.

Final Thoughts

Following a month-by-month planting and care schedule ensures that tomatillo plants grow vigorously and yield abundantly. From my decades of hands-on experience, consistent attention from seed starting to harvest, combined with proper spacing, soil prep, and pest monitoring, produces the best results. A well-planned calendar keeps plants healthy and maximizes flavorful fruit throughout the season.