Poblano Peppers in Zone 7B — Pacific Northwest

Poblano peppers are a fantastic addition to any Pacific Northwest garden. Their mild heat brings a depth of flavor to dishes that's perfect for our cool summer nights, and they're incredibly versatile in the kitchen. Plus, there's nothing quite like the satisfaction of harvesting your own peppers after nurturing them through our overcast spring days.

While our region's mild summers and wet springs can present some unique challenges for warm-season crops, don't let that deter you. With careful timing and a few tricks, you can absolutely grow beautiful Poblanos. Our long, mild fall also extends the growing season, giving you every chance to succeed within our 193-day growing season.

Starting Poblano peppers indoors is the way to go here in the PNW to get a jump start on our relatively short warm season. You'll want to sow your seeds indoors from late February through mid March, giving them about 8 weeks to get established before transplanting. This head start is crucial since our soil can be slow to warm up in the spring.

Use seed trays or small pots filled with a good seed-starting mix. Keep the soil consistently moist, and consider bottom watering to prevent damping-off, which can be a problem in our wet springs. Provide plenty of light – a grow light is ideal, especially with our often overcast spring days – and maintain a consistent temperature of around 70-75°F for optimal germination.

Transplanting your Poblano pepper seedlings outdoors should happen from late April through late May, once the danger of frost has passed and the soil has warmed up a bit. Before you plant them in the ground, it's essential to harden them off. This means gradually exposing them to outdoor conditions for about a week, increasing the amount of time they spend outside each day.

Choose a sunny spot in your garden with well-drained soil and space the plants 18-24 inches apart. Be mindful of potential late frosts that can occur even in late April or early May in the PNW. If a frost is predicted, cover your young plants with blankets or row covers to protect them.

Consistent watering is key for Poblano peppers, especially during our dry summer months. While we don't often experience scorching heat, those large leaves can lose water quickly, and even moisture is essential for developing those thick-walled fruits. Aim to keep the soil consistently moist, but not waterlogged.

During our wet springs, you might not need to water much at all, but once the dry summer months arrive, increase watering to about 1-2 inches per week, depending on rainfall. Stick your finger about 2 inches deep into the soil to check for moisture – if it feels dry, it's time to water. Watering at the base of the plant is best to avoid wetting the leaves, which can encourage fungal diseases in our occasionally humid conditions.

Signs of underwatering include wilting leaves and slow growth. Overwatering, on the other hand, can lead to yellowing leaves and root rot. A layer of mulch around the base of the plants can help retain moisture and suppress weeds, which is especially useful during our drier summer months.

While not always necessary, providing support for your Poblano pepper plants can be a good idea, especially as they get larger and the fruits start to weigh down the branches. Poblano plants tend to be bushy, and those big peppers can cause branches to snap.

Staking is a simple and effective method. Use sturdy stakes made of wood or metal, and insert them into the ground near the plants at planting time. As the plants grow, gently tie the stems to the stakes with soft twine or plant ties. This will help prevent the branches from breaking under the weight of the peppers.

Poblano peppers benefit from a little pruning to encourage better airflow and fruit production. Pinch off the early flowers that appear on the plant. This directs the plant's energy into vegetative growth, resulting in a stronger, more productive plant later in the season.

Throughout the growing season, remove any interior branches that are crowded or crossing each other. This will improve air circulation and reduce the risk of fungal diseases, which can be a concern in our occasionally humid climate. As the end of the season approaches (late October in the PNW), you can remove any new flowers to encourage the plant to focus its energy on ripening the existing peppers before the first frost.

You can expect to start harvesting your Poblano peppers from mid July through early September, about 80 days after transplanting. Look for peppers that are dark green, glossy, and firm to the touch. These are ready to pick for fresh use.

To harvest, use pruning shears or a sharp knife to cut the pepper from the plant, leaving a small piece of stem attached. Be careful not to damage the plant while harvesting. Regular harvesting encourages the plant to produce more peppers. If frost threatens in late October, harvest any remaining peppers, even if they aren't fully ripe. They will often ripen indoors if stored in a warm place. You can even let them turn red on the vine for making dried ancho peppers!

Here are some common problems you might encounter with Poblano peppers in the PNW:

Blossom Drop

• What it looks like: Flowers fall off without setting fruit. Small fruit yellows and drops. Plant looks healthy but produces no fruit.
• What causes it: Temperature stress is a big factor. Although our summers are mild, occasional heat waves can cause blossom drop. Low humidity, excess nitrogen, or poor pollination can also contribute.
• How to fix/prevent it: Be patient – fruit set usually resumes when temperatures moderate. Provide afternoon shade during extreme heat. Keep plants well-watered, but avoid over-fertilizing with nitrogen. Hand-pollination can help, especially if you don't see many bees.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: Rapid-reproducing sap-sucking insects. Populations explode in warm weather. Ant colonies may farm them for honeydew.
• How to fix/prevent it: A strong spray of water can knock them off. Encourage ladybugs and lacewings (natural predators). Insecticidal soap can be effective for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer, which attracts them.

Pepper Maggots

• What it looks like: Premature ripening, misshapen fruit, small dark stings on the pepper surface.
• What causes it: Adult pepper fruit flies lay eggs under the pepper skin. The larvae burrow through the fruit, causing damage and rot.
• How to fix/prevent it: Use sticky traps to catch adult flies. Insecticide sprays can be effective if applied when flies are active. Remove and destroy any infested fruit.

Sunscald

• What it looks like: White, papery patches on fruit exposed to direct sun. Affected areas may blister and become susceptible to rot.
• What causes it: Intense, direct sunlight on fruit, usually after leaves are removed or lost to disease, suddenly exposing previously shaded fruit.
• How to fix/prevent it: Avoid over-pruning foliage. Use shade cloth during heat waves. Maintain healthy foliage to shade fruit naturally. If fruit is already exposed, drape a small piece of row cover over it.

Pacific Northwest Specific Challenges: Late blight, while more common in tomatoes, can also affect peppers. Ensure good air circulation and avoid overhead watering to minimize the risk. Cool soil in spring can stunt growth, so be patient and wait until the soil has warmed up before transplanting. Our short heat can also be a challenge, so choose a sunny location and consider using row covers to trap heat and extend the growing season. Slugs can also be a problem, especially for young seedlings, so use slug bait or other control methods to protect your plants.

Companion planting can be a great way to improve the health and productivity of your Poblano peppers. Tomatoes are excellent companions because they share similar growing requirements and can help protect each other from pests. Basil is another great choice, as it repels aphids and other insects, and it's delicious paired with peppers in the kitchen. Carrots help to loosen the soil around the pepper plants, improving drainage. Onions also repel pests and have antifungal properties that can protect against diseases.

Avoid planting fennel or kohlrabi near your Poblano peppers. Fennel inhibits the growth of many plants, including peppers. Kohlrabi can attract pests that also attack peppers.