Ah, the delightful fragrance of sweet peas! Join me as we harvest, sow, and grow this annual flower (there are also perennial varieties) so your garden is filled with fragrant flowers by late winter—early spring.

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Sweet Peas

Imagine the delicate blooms and sweet fragrance of sweet peas (Lathyrus odoratus) gracing your cutting garden. Beloved for their beauty, these plants are a favorite in many gardens, including mine. Harvesting their seeds, sowing them at the right time, and providing proper care can ensure a vibrant display year after year. Collecting seeds from mature pods allows you to preserve your favorite varieties and continue their legacy in your garden. With a little attention to timing and planting techniques, you can enjoy the charming beauty of these delicate flowers from season to season.  These sweet pea plants tend to bloom from late winter into early summer.

Sweet pea seeds are small, round, and have a hard seed coat, typically dark brown or black. They are harvested from mature seed pods once they turn a papery brown color. Sweet pea seeds are easy to collect and store, making them ideal for gardeners who want to grow their plants from seed.

 Harvesting Sweet Pea Seeds 

Here’s a simple guide to harvesting sweet pea seeds. As the summer heat sets in, the plants will dry up and turn brown, making this the ideal time to harvest your seeds. Wait for the dried pods to turn a papery, brown color, then carefully remove them from the plant. This way, you’ll have several new plants next year.  

When to Harvest Sweet Pea Seeds

The timing for harvesting sweet pea seeds depends on your growing zone. I usually harvest my seeds in Southern California  (Zone 10b) in late July or early August. However, in most other parts of the country, sweet pea seeds are typically ready for harvest closer to early September, at the end of the growing season.

  Signs that the pods are ready

To know when sweet pea pods are ready for harvesting, watch for several key signs. The most important indicator is the color and texture of the pods: they should turn from green to light brown, resembling the appearance of a paper bag. The pods will also feel dry and brittle to the touch, and you may hear a slight rustling sound when they are shaken, signaling that the seeds inside have matured and loosened. At this stage, the pods may start to split slightly along their seams, another sign that the seeds are fully developed and ready to be collected.   

 Best time of day to harvest

The best time to harvest sweet pea seeds is in the early morning, ideally on a dry day when any dew has evaporated. Morning harvesting ensures that the seeds are cool and not exposed to the intense heat of the day, which can affect their viability. A dry day prevents moisture from seeping into the seed pods, reducing the risk of mold or rot during storage.

How to Collect Sweet Pea Seeds

Tools Needed 

• Garden Gloves – Protect your hands while handling the plants and pods.
• Pruning Shears or Scissors – For clean-cut seed pods from the plant.
• Paper Bags or Envelopes – Collect and store the seeds, allowing them to breathe and remain dry.
• Marker or Pen – To label the paper bags or envelopes with the seed variety and date of harvest.
• Tray or Flat Surface – To spread the seeds out to dry after harvesting, ensure they don’t retain moisture.
• Paper Towel: Line your tray with a paper towel.

Techniques for Collecting Seeds from Sweet Pea Flower

A simple technique for saving the pea-like seeds from the garden is gently squeezing the dried sweet pea seed pods along their seams. Hold the pod over a clean tray or bowl, then use your fingers to carefully apply pressure along the seam until the pod splits open. Once open, use your thumb to brush the seeds out into the tray or bowl gently. Use caution. This method helps prevent seeds from scattering and makes collecting them all in one place easy. Afterward, spread the seeds in a single layer on the tray and leave them in a cool, dark place for a few days to ensure they are completely dry before storing them.

Harvesting and Storing Sweet Pea Seeds

To properly store sweet pea seeds, place them in a paper bag or envelope, allowing air circulation and preventing moisture buildup that could lead to mold or rot. Ensure the paper bag or envelope is labeled with the seed variety and the collection date to keep track of freshness. Store the seeds in a cool, dry place, such as a cupboard, pantry, or drawer, away from direct sunlight and humidity. A temperature of around 40-50°F (4-10°C) is ideal for seed storage.

 Sowing Sweet Pea Seeds 

 Choosing the right location 

Choosing the right location to plant sweet peas is essential for healthy growth and a vibrant display of flowers. Sweet peas thrive in a spot with plenty of sunlight—ideally, at least six to eight hours of full sun each day. While they can tolerate light afternoon shade, especially in hotter climates, they perform best with ample morning sunlight.  

 Sweet peas prefer well-drained, fertile soil rich in organic matter.

Tip from wendy’s garden:

Add perlite to your soil. It improves drainage, and perlite also retains some moisture, providing a balance that helps keep the soil hydrated without becoming waterlogged. This is especially useful for plants that prefer well-drained but consistently moist soil.

    Preparing the Soil   

Preparing well-drained soil is crucial, as sweet peas do not like their roots soaked. Follow my directions below for the best results. 

• Mixing in compost or fertilizer: The ideal soil for sweet peas is loamy, which means it has a balanced mix of sand, silt, and clay. This provides good drainage while retaining enough moisture for the roots. To enrich the soil, incorporate organic matter like compost, well-rotted manure, or leaf mold to improve its texture and nutrient content in your garden beds.
•  Tilling and leveling the soil—Tilling and leveling the soil creates a loose, even bed that helps to create well-drained soil and root penetration, providing an ideal environment for sweet peas to thrive.
•  Soil PH– The best soil pH for sweet peas is between 6.5 and 7.5, which is neutral to slightly alkaline. This pH range allows sweet peas to absorb nutrients effectively, promoting healthy growth and abundant flowering.
• If the soil is too acidic (below 6.5), you can raise the pH by adding garden lime. For soils that are too alkaline (above 7.5), incorporating organic matter like compost or peat moss can help to balance the pH. Regularly testing the soil can help you maintain the optimal pH for growing sweet peas.