How to Grow Poblano Peppers From Seed to Harvest

Poblano peppers are the big, glossy, heart-shaped chiles behind chiles rellenos and rajas, and when they ripen red and dry they become anchos, the backbone of mole and chili powder. They are mild, productive and easier to grow than superhot peppers, but they do have two quirks: they need a long, warm season, and the plants get tall and top-heavy with fruit. Start seeds early, give them heat, stake them before they flop, and a few plants will keep a household in poblanos from midsummer until frost.

Part of our Vegetable Gardening & Raised Beds guide →

In this guide

1. Poblano Basics
2. Starting Poblano Seeds Indoors
3. Transplanting and Spacing
4. Supporting Heavy Poblano Plants
5. Watering and Feeding
6. Growing Poblanos in Containers
7. When and How to Harvest
8. Common Problems and Fixes
9. Poblanos Compared With Other Chiles
10. Saving Poblano Seed
11. Frequently Asked Questions

Poblano Basics

Poblano is a type of Capsicum annuum, the same species as bell peppers, jalapeños and cayennes. The name refers to the fresh green pod; the dried red pod is sold as an ancho. Fruits are 4 to 6 inches long, about 2 to 3 inches wide at the shoulders, with thick walls that roast and peel well. Heat is mild, but it is not uniform. Plants stressed by drought or extreme heat tend to produce hotter fruit, and an occasional pod surprises you.

Varieties to look for

• Ancho San Martin: a hybrid known for early, uniform fruit on compact plants; a good pick for shorter northern seasons.
• Tiburon: a hybrid with large, dark green pods and good disease resistance.
• Ancho Gigantea: an open-pollinated type with very large fruit; save your own seed.
• Generic “Poblano” or “Ancho 101”: open-pollinated seed sold by many companies; reliable but more variable in size and heat.

In Zones 3 to 5 with short summers, choose a hybrid labeled 65 to 70 days to maturity. In the South and West, any variety will have time to ripen red.

Starting Poblano Seeds Indoors

Except in the Deep South and low desert, poblanos need a head start indoors. Direct-sown seed simply runs out of season before the fruit ripens.

1. Timing: count back 8 to 10 weeks from your average last frost date. For a mid-May last frost, that means early to mid-March.
2. Containers: sow in cell trays or small pots filled with a fine seed-starting mix, two seeds per cell, 1/4 inch deep.
3. Heat: pepper seeds germinate slowly in cool soil. A seedling heat mat that holds the mix at 80 to 85°F brings germination down to about 7 to 14 days. At 65°F it can take three weeks or fail.
4. Moisture: keep the mix evenly damp, not wet. A humidity dome helps until sprouts appear, then remove it.
5. Light: as soon as seedlings emerge, give them 14 to 16 hours of bright light. Hang LED shop lights 2 to 4 inches above the leaves and raise them as plants grow. A windowsill alone produces leggy, weak seedlings.
6. Thinning: when true leaves appear, snip the weaker seedling in each cell at soil level.
7. Potting up: at 3 to 4 weeks, move seedlings to 3- or 4-inch pots and begin feeding with a quarter-strength balanced liquid fertilizer every week or two.
8. Air movement: a small fan on low for a few hours a day builds sturdier stems.

Hardening off

A week to ten days before transplanting, start setting seedlings outside in a sheltered spot for an hour or two, increasing time and sun exposure each day. Bring them in if nights drop below 50°F. Skipping this step causes sunscald on leaves and a stall that can cost you two weeks of growth.

Transplanting and Spacing

Peppers sulk in cold soil. Wait until nights are reliably above 55°F and the soil 4 inches down reads at least 65°F, which in most of the US is two to three weeks after the last frost date. Planting earlier rarely gains you anything; cold-stunned plants often get passed by later transplants.

• Sun: full sun, 8 hours or more. In the hottest desert areas, light afternoon shade cloth reduces fruit sunscald.
• Soil: loose, well-drained, rich in organic matter, pH 6.0 to 7.0. Mix 2 inches of compost into the bed before planting.
• Spacing: 18 to 24 inches between plants, rows 24 to 36 inches apart. In a raised bed, plant on a 18-inch grid.
• Depth: set transplants at the same depth they grew in the pot, or up to an inch deeper.
• Mulch: once the soil has warmed, add 2 to 3 inches of straw or shredded leaves to hold moisture and keep soil temperature steady.

Black plastic mulch laid two weeks before planting is a useful trick in cool northern gardens; it can raise soil temperature several degrees and push harvest earlier.

Supporting Heavy Poblano Plants

This is where many poblano crops are lost. Plants grow 2 to 3 feet tall in most gardens and up to 4 feet in long, hot seasons, with brittle branches loaded with big pods. A summer thunderstorm can snap them at the main fork or tip the entire plant over.

• Single stake: drive a 4- to 5-foot wooden or metal stake 4 inches from the stem at planting time, before roots spread. Tie the main stem loosely with soft ties every 8 to 12 inches as it grows.
• Tomato cage: a standard cone-shaped cage works well for poblanos and supports side branches better than a single stake.
• Florida weave: for a row of plants, set stakes every two plants and run twine along both sides at 8- to 10-inch intervals as plants grow.

Many growers also pinch out the first flower or two on young transplants. It redirects energy into roots and branching and usually leads to more fruit overall.

Watering and Feeding

Water: give 1 to 2 inches per week, more during heat waves and in containers. Water deeply at the base so the top 6 inches of soil is moist, then let the surface dry slightly before watering again. Drip irrigation or a soaker hose under mulch is ideal. Swings between bone-dry and soggy cause blossom-end rot and flower drop.

Fertilizer: mix a balanced slow-release vegetable fertilizer into the planting hole according to label rates. Once plants begin flowering, side-dress with a fertilizer lower in nitrogen and higher in phosphorus and potassium every 3 to 4 weeks. Too much nitrogen gives you a beautiful 4-foot bush with very few peppers. A tablespoon of Epsom salt per gallon of water is a common folk remedy, but only helps if a soil test shows magnesium is actually low.

Growing Poblanos in Containers

Poblanos grow well in pots if the pot is big enough. Use at least a 5-gallon container per plant, ideally 7 to 10 gallons, filled with quality potting mix rather than garden soil. Containers dry fast in summer, so expect to water daily in July and August. Dark pots on a hot patio can overheat roots; light-colored or fabric pots help. Our guide to growing chili peppers in pots covers container mixes and watering schedules in more detail.

When and How to Harvest

Stage	What it looks like	Timing	Best use
Green	Glossy, very dark green, 4 to 6 inches, firm walls	About 65 to 80 days after transplant	Roasting, stuffing, rajas
Turning	Dark green with brown or red patches	1 to 2 weeks later	Roasting; slightly sweeter
Red	Fully deep red	2 to 4 weeks after green stage	Drying into anchos, sauces

Cut poblanos with pruners or scissors, leaving a short piece of stem; pulling can break the brittle branches. Picking green fruit regularly encourages the plant to set more. If you want anchos, leave some fruit on the plant to ripen fully red, then dry them on a string (a ristra) in a warm, airy spot or in a dehydrator at about 125 to 135°F until leathery.

Before the first fall frost, harvest every fruit, including small ones. Green poblanos keep about a week in the refrigerator; roasted and peeled, they freeze well for months.

Common Problems and Fixes

Problem	Cause	Fix
Flowers fall off without setting fruit	Nights below 55°F or days above 90°F; uneven watering	Keep soil evenly moist; fruit set resumes when temperatures moderate
Dark sunken patch at the blossom end	Blossom-end rot from inconsistent watering	Mulch and water on a steady schedule
Pale, papery patches on fruit	Sunscald	Keep leaf cover; use 30 percent shade cloth in extreme heat
Curled, sticky leaves	Aphids	Spray off with water; insecticidal soap for heavy infestations
Leaves with dark water-soaked spots	Bacterial leaf spot	Remove affected leaves, avoid overhead watering, rotate crops
Lots of leaves, few peppers	Excess nitrogen	Switch to low-nitrogen fertilizer

Flower drop is the most common complaint in midsummer; our guide on why pepper flowers drop walks through each cause. Rotate peppers, tomatoes and eggplants to a new bed each year to limit soilborne disease.

Poblanos Compared With Other Chiles

If poblanos go well, branching out is easy. Serranos and jalapeños follow the same seed-starting and care routine with smaller plants and hotter fruit; see how to grow serrano peppers. Superhots such as ghost peppers need even more heat and a longer season, which we cover in how to grow ghost peppers. For crop planning across the whole garden, start at our vegetable gardening hub.

Saving Poblano Seed

Open-pollinated poblanos such as Ancho Gigantea come true from seed if they did not cross with other peppers. Peppers are mostly self-pollinating but bees can cross them, so isolate plants by at least 50 feet or bag a few flower clusters with fine mesh before they open. Let the chosen fruit ripen fully red and slightly soft, scrape the seeds onto a paper plate, dry them for one to two weeks, and store in a labeled envelope in a cool, dry place. Seed from hybrids such as Tiburon will not reproduce the parent reliably.

Give poblanos an early indoor start, warm soil, a sturdy stake and steady water, and they are one of the most rewarding chiles you can grow.