How to Grow Serrano Peppers
How Hot Are Serrano Peppers?

How to Grow Serrano Peppers

Below are some tips and instructions for growing and harvesting your serrano peppers.

Serrano peppers are native to the mountains of south-central Mexico and now, many areas of the Bronx. The plants can grow to a height of 2-3 feet and yield prodigious quantities of peppers. With a Scoville rating between 10,000 and 25,000 they are slightly spicier than a mild jalapeño (not sure what the a Scoville rating is? click here). That’s hot but it isn’t going to kill you.

Typically eaten fresh, serrano peppers are commonly used in making pico de gallo and salsa, as the chili is particularly fleshy compared to others, making it ideal for such dishes.

Mature serrano pepper plants will generally reach a max height of between 1.5 to 5.0 ft tall. Each plant can hold up to 50 pepper pods.

For the purpose of the Bronx Hot Sauce we encourage you to harvest the peppers GREEN. Peppers can generally be harvested about 2.5 to 3 months after transplanting when green, depending on weather conditions.


Serrano Peppers

Early Season

Sow seeds indoors, 8 weeks before you anticipate transplanting outside. Seed germinates best when soil temperature is 80 F or higher. It will not germinate below 55 F.

Keep plants indoors in a warm (70 F during the day, 65 F at night), sunny location. Lack of light will produce leggy, unproductive transplants.

Don’t rush to transplant outside. Set plants out 2 to 3 weeks after average last frost when the soil has warmed and the weather has settled. Cold temperatures can weaken plants and they may never fully recover. A few days at 60 F to 65 F with reduced water will help harden plants and reduce transplant shock. Over-hardened plants grow slowly after transplanting.


Plant your pepper plants 12 to 24 inches apart, in rows 24 to 36 inches apart, or spaced about 14 to 16 inches apart in raised beds. Select a location that receives plenty of light and heat, and has not been used for tomatoes, potatoes or other members of this family for the past couple of years. Peppers will do best with soil that is fertile, lightweight, slightly acidic (pH 5.5-7.0) and well-drained.

Mulch plants after they are established and the soil has warmed to retain moisture and control weeds.

Your plants need a steady supply of water. Water deeply at least 3 times per week, especially in the driest point in summer. Peppers like the heat, so full sun exposure is ideal, but they also thrive with more water.

Peppers can be temperamental when it comes to setting fruit if temperatures are too hot or too cool. Nighttime temperatures below 60 F or above 75 F can reduce fruit set.


Don’t recommend you use synthetic pesticides or fertilizers in your community gardens. If you’d like to fertilize your plants, add finished compost in the planting holes when you transplant, or topdress the garden surface with a 2-3 inch layer of compost.

You can also use fully composted chicken manure if your garden keeps chickens. Fish and seaweed-based fertilizers like Neptune’s are also good. Dilute them in water and drench the soil around the roots of the plants, following the recommendations on the package.

Stake your plants for best performance. Once they are heavy with peppers, your plants will grow best when staked, with peppers kept off the ground.

Too much nitrogen fertilizer may promote lush vegetative growth but fewer fruits. Peppers usually respond well to phosphorus fertilizer.

Do not plant in same spot more than once every 4 years.

Well that’s a wrap. Now you know how to grow serrano peppers!

Start Growing with these Serrano Pepper Seeds