Growing Sweet Peas Indoors

Last Updated On: August 22, 2022

A Note On Toxicity
Containers and Planting
Sunlight
Water and Feeding
Support
Pruning
Moving Outdoors
Growing Sweet Peas Indoors
Sweet Peas FAQ

Sweet peas are a beautiful plant is perfect for indoor growing. Ornamental sweet peas feature bright flowers, and create an instant focal point for any room they’re in. In this article, we’ll be breaking down growing sweet peas indoors and providing you with all the information you need to start growing these wonderful plants today.

A Note On Toxicity

First off, it’s important to understand that ornamental sweet peas are poisonous. These are not the same as edible peas you can buy at the grocery store, although they are related. That said, their toxic content is generally low, and usually only becomes an issue after a large amount is consumed.

If you’re looking to grow peas to eat, then you should be careful in choosing a variety. Many sweet peas are not meant for consumption, and only for visual appeal.

Containers and Planting

The first step is to select the variety of sweet pea you’ll be growing. While you can grow most kinds indoors, it’s best to go with a dwarf or bush variety. These won’t grow as tall as traditional varieties, which make them much easier to grow when you have limited indoor space.

When planting, you’ll want to give at least 6” between plants, so choose an appropriate sized container. Make sure to use a high-quality potting soil that is rich in nutrients to start your plants in.

If you’re starting from seeds, score the shells a bit with a knife. This helps them absorb water, and increase the chance that they’ll germinate. Plant them about ¼” deep into the soil and lightly cover. Water the soil immediately after planting.

If you’re starting in a seed tray, you can transplant the seedlings when they are a few inches tall and have about 3-4 leaves. Once transplanted, water right away to help them adapt to their new home.

Sunlight

Sweet peas need about 6-8 hours of bright light per day for optimal growth. This is one of the biggest issues indoor gardeners will face, and the primary cause of a failed sweet pea crop.

If you’re having trouble hitting this number, especially in winter, use a small grow light to supplement. You’ll likely want to get closer to 10 hours of light per day when using a grow light to account for the differences in artificial vs. natural light.

You also want to rotate your plant every couple of days to give it even lighting. If you don’t, you’ll often see it bending towards the light. This can lead to spindly growth that is more likely to topple, and require extra work in providing support.

Water and Feeding

Keep the soil of your sweet peas moist, and check frequently to prevent it drying out. Sweet peas should be watered every few days, especially early on in their growing season. Check the top inch of soil, and water when dry until the soil is saturated. Once the plant flowers, you can cut back and water a little bit less.

Sweet peas are also heavy feeders, so you’ll want to fertilize them every 3-4 weeks. Use a water soluble fertilizer diluted to half strength for containers to prevent shocking the plants. You can also use a slow-release fertilizer as instructed.

Support

Sweet peas are a climbing plant, so you’ll need to provide some type of support. A small trellis support is the easiest, and will provide the support your plant needs to climb.

You can also use stakes or other supports, but these often require a bit more work to set up. Whichever route you choose, don’t neglect this step. Without proper support your plant will not be able to support itself, and this will hamper its growth as well as how much you can harvest.

Pruning

During your plant’s growth some light pruning might be needed. This is generally easy maintenance and cleanup that is expected of all potted plants.

Eventually, parts of the plant will begin to brown and die out. That’s perfectly okay and expected. When this happens, simply prune back the plant. Once the whole plant dies, you can replant another one in its place and begin the process anew. Most sweet peas are annuals, so you can only expect them to grow for a single year. A handful will last multiple years, but you’ll need to select the correct variety for it to do so.

Also, you can also cut the stems with the flowers to create a bouquet before they die off naturally. The flowers are quite beautiful, and make a great centerpiece. Different varieties bloom different colors, so if your goal is looks find one with blooms that match your style.

Moving Outdoors

Many gardeners will look to start their sweet peas indoors and move them outside for the summer. This gives you a larger sized plant as the plant will go through a lot of growth indoors. If this is your goal, look to start planting about 1-2 months before your last frost date.

Once temperatures reach an average of 60-70°F outside you can begin moving your plant outdoors. You’ll want to go through a hardening process where you gradually expose your plant to elements outside before moving them there permanently. Start with a few hours per day, and gradually build up to leaving them outside all day. This is especially important for adjusting to the increased intensity of sunlight your plant will experience outdoors.