Poblano Peppers in Zone 8A — Pacific Northwest

Poblano peppers are a rewarding addition to any Pacific Northwest garden. Their mild heat brings a unique flavor to salsas and stuffed peppers, and they thrive in our cool nights which enhance their taste. There's nothing quite like harvesting your own peppers after a long season.

While the Pacific Northwest isn't known for scorching summers, our mild weather and 203-day growing season are plenty to ripen poblanos if you start early. With a little planning around our wet springs and the occasional temperature swing, you can enjoy a bountiful harvest.

Starting poblano peppers indoors is essential in the Pacific Northwest to get a head start on our growing season. You'll want to sow your seeds mid-February through mid-March, about eight weeks before you plan to transplant them outside. Use seed trays with a good seed-starting mix, and make sure they're in a warm spot, ideally with a heat mat underneath, since our springs can be cool.

A sunny windowsill might not provide enough light, especially with our overcast spring days, so consider using grow lights. Keep the soil consistently moist, and water from the bottom by placing the tray in a shallow dish of water to encourage strong root growth. This prevents damping off, which can be a problem in our wet springs.

Transplant your poblano peppers outdoors late April through late May, once the danger of frost has passed and the soil has warmed up. Before planting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week. Start with an hour or two of shade and increase the time each day.

Plant your seedlings 18-24 inches apart in a sunny spot with well-draining soil. Keep an eye on the weather forecast, as late frosts can still occur. If frost threatens, cover your young plants with row covers or blankets.

Poblano peppers need consistent moisture, but overwatering is a concern in our climate, especially during the wet springs. During the dry summer months, you'll need to water more frequently than you might think, even with our mild heat. Stick your finger about two inches into the soil – if it feels dry, it's time to water.

Aim for about 1-2 inches of water per week, depending on rainfall. Water at the base of the plants to avoid wetting the foliage, which can encourage fungal diseases in our sometimes humid conditions. Signs of underwatering include wilting leaves, while yellowing leaves can indicate overwatering.

Mulching around your plants with straw or compost helps retain moisture and suppress weeds, a win-win in the PNW.

While poblano peppers have a bush-like growth habit, they can get quite large, and the weight of the peppers can cause branches to break. Providing support is a good idea, especially if you're aiming for a heavy harvest. Staking is a simple and effective method.

Install sturdy stakes near the base of each plant at transplant time, driving them deep enough into the ground to provide good support. As the plants grow, gently tie the stems to the stakes with soft twine or plant ties. This will help prevent branches from snapping and keep the peppers off the ground, reducing the risk of rot.

Pruning poblano peppers can improve airflow and encourage fruit production. Early in the season, pinch off any flowers that appear before the plant is a foot tall. This directs the plant's energy into vegetative growth, resulting in a stronger plant that can support more peppers later on.

Throughout the season, remove any yellowing or damaged leaves, as well as any suckers (small shoots that grow from the base of the plant). Towards the end of the season, around late October as the first frost approaches, you can remove any new flowers that haven't set fruit. This encourages the plant to focus its energy on ripening the existing peppers.

In the Pacific Northwest, you can expect your first poblano pepper harvest mid-July through late August, about 80 days after transplanting. The peppers are ready to harvest when they're dark green, glossy, and firm to the touch. You can also let them turn red on the vine for a sweeter flavor and to make dried ancho peppers.

To harvest, use pruning shears or a sharp knife to cut the stem just above the pepper. Be careful not to damage the plant when harvesting. Regular harvesting encourages the plant to continue producing more peppers.

If a frost is in the forecast (late October), harvest all remaining peppers, even if they're still green. They will ripen indoors if stored in a cool, dry place.

Here are some common problems you might encounter growing poblano peppers in the Pacific Northwest:

Blossom Drop

• What it looks like: Flowers fall off without setting fruit, and small fruit yellows and drops. The plant looks healthy but doesn't produce peppers.
• What causes it: Temperature stress. Poblano peppers don't set fruit well when nighttime temperatures stay above 75°F. Although rare, daytime temperatures above 95°F can also cause issues. Low humidity, excess nitrogen, or poor pollination can also contribute.
• How to fix/prevent it: Be patient – fruit set will resume when temperatures moderate. Provide afternoon shade during periods of extreme heat. Keep plants well-watered and avoid excess nitrogen fertilizer. Try hand-pollination by gently shaking the plant or using a small brush to transfer pollen.

Aphids

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

Pepper Maggots

• What it looks like: Small, white, legless larvae burrowing inside the pepper fruits. Premature fruit drop and distorted or rotting peppers.
• What causes it: Pepper maggot flies lay eggs on the developing peppers. The larvae hatch and tunnel inside.
• How to fix/prevent it: Use sticky yellow traps to catch adult flies. Cover plants with row covers to prevent flies from laying eggs. Remove and destroy any infested peppers immediately.

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 periods of extreme heat. 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 can be a problem in our region, especially with tomatoes, and can affect peppers as well. Ensure good airflow around your plants and consider using blight-resistant varieties. Our cool soil in spring can stunt early growth, so be patient and wait until the soil has warmed up before transplanting. Slugs can also be a nuisance, so use appropriate control measures like beer traps or diatomaceous earth. Our dry-summer humidity usually keeps fungal diseases at bay, but watch out for late blight in wet years.

Poblano peppers benefit from companion planting in the Pacific Northwest. Tomatoes make excellent companions because they enjoy similar growing conditions, such as full sun and well-drained soil. Basil is another great choice, as it repels pests like aphids and whiteflies, and it's said to improve the flavor of peppers.

Carrots and onions are also good companions, as they deter soil-borne pests and don't compete with peppers for nutrients. Avoid planting fennel and kohlrabi near poblano peppers. Fennel inhibits the growth of many plants, and kohlrabi can attract pests that also affect peppers.