How To Grow Serrano Peppers (Plus Heat Scale!)

Serrano Peppers

Are you looking for a pepper that is a notch higher on the Scoville Scale than jalapeño but not as spicy as habanero?

Your landing point could be serrano peppers. They are medium-hot chili peppers that are easy to grow. You do not need much garden space to get a good yield.

Serrano Peppers needs a place to grow, must be planted at a specific time of the year, you must optimize the soil, temperature and humidity, and it needs fertilizer and water to grow best.    


Serrano Peppers Need Certain Things To Grow:  

Serrano peppers grow well in a sunny location. In colder climates, it is better to plant them indoors.

Serranos are typically ready for harvest after three months of planting.

While they are perennials, they are treated as annuals when grown outside of their preferred hardiness zones, thus you need to start with a new plant every year.

Selecting Where to Plant Serrano Peppers  

Pick a spot in your garden that will give your plant direct sunlight. It should have rich soil that is well-draining. You can also opt to plant your serranos in a container.

Planting serranos alongside other plants is a good idea. Other peppers, basil, tomatoes, parsley, parsnips, carrots, garlic, beets, radishes, and onions are the best companion plants for serranos.

Serranos and other peppers do not do well when planted near kohlrabi or fennel. You can also rotate your pepper plants every year.

You should avoid, though, planting them where other plants belonging to the Solanaceae family have been planted during the past two years.

When to Plant Serrano Peppers

Spring is the best time to plant serrano peppers.  This is after the last frost threat is over.

You can start planting the seeds indoors six to eight weeks before the last frost date in spring. You can replant them outdoors when temperatures are above 550F.

Serrano Peppers Soil Requirements

Serranos need well-draining and organically rich soil. A neutral to slightly acidic soil is the best. You can add about one inch of compost to your soil to make it more fertile.

Light Requirements for Serrano Peppers

Serrano peppers are tropical plants, so they need full sun to grow and thrive. They should ideally have about six hours of direct sun per day.

Best Temperature and Humidity for Serrano Peppers

Serranos thrive in a humid and warm environment, about 750F.  They are sensitive to frost and are usually grown as annuals when planted outside their native tropical climate.

In warmer weather, make sure your serranos get enough water.

Fertilizer Requirements for Serrano Peppers

Serranos are heavy feeders. They should be fertilized at the time of planting.

Fertilize, too, throughout the growing season. It is recommended to use a balanced vegetable fertilizer.

Tomato fertilizers typically work well with chili peppers.  You can use a good 5-10-10 fertilizer which means 5% nitrogen, 10% phosphorus, and 10% potassium.

Water Requirements for Serrano Peppers

Serranos thrive best in consistently moist, but not soggy soil. Water your serranos 1 – 2 inches down when they become dry but making sure not to waterlog the soil.

It is also best to water your plants at the base instead of from above to prevent the development of mildew.

Harvesting of Serrano Peppers

Your serrano peppers will typically be ready for harvest about 80 days after planting. You can wait for the peppers to mature more in size so you can get the best flavors.

It is recommended to harvest serranos when they are still green instead of allowing them to turn red or another color.

They become susceptible to rotting when they left to remain longer on the vine.

You can use shears to cut your serranos off the vine. Carefully pull them to avoid injuring the tender stems of your plant.

Because of their capsaicin content, make sure to always wear gloves when handling your serrano plant.

 Pollination of Serrano Peppers

Serrano peppers are self-pollinating. They pollinate with the help of animals in your garden and the wind. You can also do your share to help them pollinate by gently shaking the plants.

Growing Serrano Peppers from Seeds

It is easy to grow serranos from seeds. You can use peat pots if you plan to start growing them in containers.

Choose containers that are big enough to hold your plant until they reach their mature size.

This is to avoid disturbing the growing seedlings when you transplant them to the ground.

Fill each pot with moist soilless potting mix. Your potting mix should be rich and well-draining- potting mix formulated for vegetables.

Add three serrano pepper seeds to each pot and slightly cover them with soil. After germination, thin them to one plant per pot. 

Serrano pepper seeds will need a good amount of warmth so the soil should be 800F to 850F. They also need plenty of sunlight.

Make sure to keep the soil moist but well-draining. In these conditions, the serrano seeds should germinate within two weeks.

Water your serrano seedlings after potting. Make sure the soil remains always moist.  Potted plants typically dry out faster than plants grown in the ground.

Tips on Growing Serrano Peppers

Overwintering Serrano Peppers

If you are planting serrano peppers outside their growing zones, place your potted plants indoors to overwinter. This should be done before any threat of fall frost.

When indoors, keep your serrano plant by the brightest window in your home – a south-facing will be the best. Water the top 1-inch of the soil when it dries out.

Make sure to also protect your plant from drying air and drafts coming out of the heating vents.

Sowing Serrano Peppers Seeds Indoors

Sow serrano seeds indoors 8 weeks before transplanting outside.

The seeds will germinate when the soil has a temperature of 800F or higher. The seeds will not germinate when the soil temperature is below 550F.

It is also important your plant gets enough sunlight, or it will produce unproductive and leggy transplants.

Staking Serrano Peppers

Stake your serrano plants. Once your plant is heavy with peppers, stakes will keep the peppers off the ground.

Serrano Peppers – Common Diseases and Pests

Compared to other members of the nightshade family, serranoes are not prone to as many diseases and pests.

These peppers are still prone to some diseases and pest infestations, though.

Verticillium wilt is a common disease that can cause the foliage of your serrano plant to wilt and turn yellow.

Whiteflies, aphids, and cutworms are common pests that can attack your serrano plant.  

These pests can be eliminated by blowing them up with a garden hose. Natural insecticidal soap will also do the trick.

Treating diseases and pests and crop rotation are some of the best techniques to keep your serrano peppers healthy.

How to Grow Serrano Peppers

Somewhere to plant, Serrano peppers grow well in a sunny location. In colder climates, it is better to plant them indoors.

Serranoes are typically ready for harvest after three months of planting. While they are perennials, they are treated as annuals when grown outside of their preferred hardiness zones, thus you need to start with a new plant every year.

What are Serrano Peppers?

Serrano peppers often sit beside jalapeños and habaneros on the grocery shelf. They are short, slender peppers. Serrano’s are frequently sold green in the grocery stores but there are some that are red, orange, and yellow.

These hot chili peppers are a popular ingredient of many Mexican dishes such as serrano rice, chiles toreador, tomatillo salsas, and stews.

Serrano peppers (Capsicum annuum ‘Serrano’) is a cultivar of the Capsicum annuum species that originated from the mountains of Mexico.

This spicy hot pepper has a ranking of 10,000 – 23,000 Scoville heat units making them about five times hotter than jalapeño but not as hot as habaneros. 

Many serranoes are between 1 and 2 inches long when mature with the larger varieties being twice the size. The pepper is narrow with a rounded top and slight taper.

Unlike other chilies, serranoes have thin skin making them perfect for salsas. They have a dark green color but mature to become red, yellow, orange, or brown.

It can be trickier to grow serranoes than other garden crops, but they are still one of the easiest types of peppers to grow.

They are best planted in the spring and will be ready for harvest after three months.

These perennials grow and thrive in areas within the 9-11 USDA hardiness zones.

The seeds, leaves, and fruits of serrano peppers contain the compound capsaicin that may create a burning sensation when it comes into contain with your skin. Make sure to always wear gloves when handling these peppers.

Popular Uses of Serrano Peppers

It is common to have an abundant harvest of serrano peppers. You can normally harvest 2.5 pounds of serranos per plant. Here are what you can do with your peppers.

Fresh Serrano Peppers. Serranos are ideal ingredients for pico de gallo and spicing up salsa recipes because of their thin skin.

You can also use the peppers for Mexican, Thai, and southwestern cuisine. You can keep fresh serranos in the fridge for longer shelf life.

Dried Serrano Peppers. Dry the serranos under the sun or with a dehydrator. You can also preserve the peppers by oven drying them.

You can use dried serrano peppers in stews, chilis, and soup for added zest and flavor.

Pickled Serrano Peppers. Turn up the heat of your pickle recipe by adding some serranos.

Roast Serrano Peppers. Roast the peppers (minus the seeds and veins) to temper their heat. Roasted serranos are perfect for marinades. They can also add spicy zest to tofu, fish, and meats.

You can freeze serrano peppers to extend their shelf life. Chop or slice the peppers and freeze them immediately, with or without seeds.

Frozen serranos can be mushy when thawed, so it is best to use them for cooking than in any other way.

Final Thoughts on Serrano Peppers 

If you are a lover of hot peppers, serrano peppers are one of the easiest peppers to grow. It does not require much care but given the right conditions can always assure you of an abundant harvest.

Here is a tip to test the potency of the potent serrano peppers.

The level of heat of serranos depends on the color of their veins. Serranos with yellowish-orange veins are the hottest.


Edited By

Patricia Godwin



Patricia Godwin

Patricia has many years of experience as a content writer on various subjects, but her first love is gardening. She’s never met a plant she didn’t like and, consequently, she writes about every type of plant you can think of. Once an avid gardener with a herb garden, a succulent rockery, and a rose garden – to mention a few. Nowadays, she’s constantly on the move searching for interesting plants to bring to your attention; and explain to you all the details you need to grow, care and maintain these plants.

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