Growing Peppers on a Windowsill: 7 Things to Know


Growing your own peppers can be a fun way to add flavor to your kitchen and color to your garden. But can you grow peppers if you don’t have an outdoor space? What if you want peppers in the winter?

You can grow peppers on a windowsill by keeping their environment similar to their ideal growing conditions. The windowsill must be 70-90°F (21-32°C), get 6-8 hours of sun, and have 50-70% humidity. Smaller peppers like those with “dwarf” or “patio” in their name will grow better in tight spaces.

Indoor plants can thrive just as well as outdoor plants, assuming you know how to care for them and provide them with everything they need. That means if you can grow a pepper plant outdoors, you can grow one on your windowsill. This guide will help you create the best possible home for your new windowsill pepper plants.

Photo of lots of vegetables growing on a windowsill
Photo by H.angelica Corneliussen

Which Types of Peppers Grow Well on a Windowsill?

You’ll want to look for cultivars that have small fruits as well as a shorter height and smaller width. The larger the fruit, the sturdier the rest of the plant needs to be to support the fruit’s weight. Similarly, the larger your windowsill, the larger a pepper plant can be.

Hot pepper plants are generally smaller than sweet peppers. There are dozens of cultivars of peppers to choose from, including a wide variety of hot and sweet flavors. When selecting seeds, look for peppers with “dwarf” or “patio” in their name, as this indicates a smaller version of the plant bred specifically for containers or indoor growing.

What Conditions are Needed to Grow Peppers on a Windowsill?

Windowsill peppers need the same conditions as they would outdoors: warmth, steady sunlight, fertile soil with good drainage, and regular watering. Peppers need potting soil with more phosphorus than nitrogen and enough loamy material to keep the roots moist without drowning them.

When you pick the windowsill to grow your peppers, make sure that it gets enough sunlight. If you live in a colder climate and you’re growing the peppers in the winter, you might need a grow light or a heated seedling mat to keep the soil warm enough.

Amazon sells BN-LINK Durable Seedling Heat Mats that work well with pepper plants. These mats help regulate the ground temperature, especially during the early seed germination phase when the plants are at their weakest.

Sunlight Hours

Even if you have a heated growing pad or a warm home, you still need to make sure your windowsill pepper plant gets between six and eight hours of sunlight every day. Peppers, like all fruiting plants, need a lot of energy to produce good fruits.

Depending on the direction your windows face, you may be able to move your plants from window to window to get enough light. However, this might be difficult if you live in a cooler climate, especially in the winter months when days are shorter.

You can use a grow light to supplement the natural sunlight and mimic the pepper’s preferred environment. If you get enough sunlight in the summer, you could also use the grow light to grow a second crop of peppers over the winter.

Temperature

The ideal soil temperature for pepper plants is at least 70 degrees Fahrenheit (21 degrees Celsius) but no more than 90 degrees Fahrenheit (32 degrees Celsius). Too low, and the peppers won’t be able to grow, but too hot, and they can dry out and wilt.

A warming mat, as previously mentioned, is a useful tool to adjust the temperature around your plants without turning up the thermostat of your entire house. However, the area around your windowsill might be warmer than the rest of your home, especially if it is in the direct path of the sun.

Jalape_o_Pepper_Lines (4)
Jalape_o_Pepper_Lines (4)

Checking the soil’s temperature is the best way to gauge what needs to be done for your pepper plants. When the soil temperature is correct, the ambient temperature around the rest of the plant should be fine as well.

Humidity

Peppers like moderate to high levels of relative humidity. in the 50-70 percent range. Any higher, and there is too much moisture, which makes the plants susceptible to diseases. Any lower, and it’ll be hard for the plant to support fruits or flowers.

A digital environmental monitor like the Vivosun Humidity Gauge from Amazon can help you keep an eye on your pepper’s environment. Humidifiers or dehumidifiers in the vicinity of your plants can help stabilize the humidity level if necessary. 

Ideal Windowsill Size

Like most plants, a pepper plant will grow in the space it’s given, but the plants will thrive best if they have room to reach their mature size. Whether or not you pick a dwarf cultivar, you should give your plants about eight to ten inches (20 to 25 cms) of space for root growth and another ten to twelve inches (25 to 30 cms) of height for the stems.

The base of the windowsill should be about eight to twelve inches wide, with at least ten inches of room to the side of each plant, unless each plant is in its own pot. Pepper plants are very leafy, so they’ll expand outward as well as upward as they grow. Depending on your windows, you may only be able to fit one plant on your windowsill at a time.

As the seedlings grow, you may need to stake them to help support the fruit’s weight, particularly if their vertical growing space is limited. You don’t want the weight of the fruit to bend or break the plants’ stems.

Steps to Growing Peppers on a Windowsill

The steps to growing windowsill peppers are much the same as growing peppers outdoors. For any kind of pepper, you’ll need to:

  1. Prep your container or planting pots with soil and compost that will retain moisture but drain well.
  2. Take note of the environment around your windowsill to ensure the soil will be warm enough and the air is humid enough. Watch the amount of sunlight in the space for a few days to make sure it gets enough light consistently.
  3. Start your seeds by gently pressing four to five into loose, moist soil, then placing the pots on your windowsill or warming mat.
  4. Water your plants regularly; peppers like about an inch (2.5 cms) of water per week.
  5. Stake your plants as needed; once the seedlings start to mature and grow blossoms, you may need to offer them a little extra support.
  6. Fertilize your plants regularly, especially as they start to produce blossoms and fruit. Keeping them well-fed will give you a better harvest.
  7. Harvest the pepper fruits as they ripen. Most will begin a light green color and turn red as they get more mature.

You can repeat these steps throughout the year to keep a supply of delicious peppers on hand. Peppers have a growing season of two to three months, meaning you can have multiple harvests throughout the year. You could even rotate the type of pepper you grow to give yourself various flavors and colors to look forward to.

Closing Thoughts

You can grow peppers on your windowsill as long as you keep their conditions comparable to their preferred outdoor environment. Since they won’t be exposed to the elements, you can adjust their environment more easily to give the plants what they need.

While growing peppers on a windowsill might take more equipment than growing them outdoors, you have more control over the environment, meaning you can avoid common gardening pitfalls. As long as you have enough space, you can grow any pepper variety you want from the comfort of your home.

Here are Some of my Favorite Gardening Products and Tools

Thank you for reading this article. I hope you found it helpful for growing some new plants in your home or garden. Here are some products I like that I hope you’ll also find helpful. These are affiliate links, and I am compensated for referring traffic. But in all honesty, these are the exact product that I use or recommend to everyone.

Soil: For high-quality soil, I really like Fox Farm Ocean Forest. I do all my growing in containers and this soil has worked great for me. I like how they use nutrient-rich contents like earthworm castings, bat guano, and composted crab and fish.

Fertilizer: Currently I am using a seaweed-based organic fertilizer call Neptunes Harvest. This is a great milder fertilizer option if you want to use something organic. If you want a more powerful fertilizer, I recommend Fox Farm Liquid Nutrient Trio, lots of people have had great growing success with this product.

Pruning Shears: Pruning shears are one of the most useful gardening tools to have because it’s important to prune your plants to keep them healthy. The pruning shears I recommend are the Gonicc 8’’ pruning shears. I like them because they are built sturdy and work both on bigger and smaller plants, so you don’t need to have multiple pruning shears.

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Supriya

Hi! I'm Supriya. I'm a home cook, bulldog mom, spicy food lover, and founder of The Spicy Trio. I have been a home cook for about 15 years and have been growing plants for the past six years.

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