Sweet peas are one of the mainstays of the annual garden. When you find a variety you love, why not save the seeds so you can grow them every year? These bright, delightful, climbing annuals are easy to grow and so is learning how and when to harvest sweet pea seeds.
Harvesting sweet pea seeds is one of those ideas that simply has no downside. It will save you money and ensure you grow sweet peas with high quality flowers. If you’re a little worried about how to collect sweet pea seeds or when to harvest them, we’ve got you covered. But don’t worry, it couldn’t be easier.
Benefits of Saving Sweet Pea Seeds
Sweet peas are charming and fragrant flowers in the legume family that bloom in every color of the rainbow except yellow. Choose heirloom sweet peas for saving seeds. Saving hybrid seeds may prove a disappointment because the resulting plants probably won’t look like the parent sweet pea plant.
If you love the heirloom sweet peas currently growing in your garden, seeds from those plants will give you more of the same gorgeous blooms. That’s one of the benefits of collecting sweet pea pods from your own backyard—it takes the guesswork out of whether next year’s crop will be as colorful and lovely as this year’s.
But there’s a second important advantage when you learn how to save sweet pea seeds from the garden: the cost. Seeds from your garden are free. While a seed packet from the store probably won’t break the bank, free is always better.
Explore dozens of gorgeous sweet pea seed varieties on Amazon.
When to Harvest Sweet Pea Seeds
Sweet peas start blooming in the spring and keep going right on until early summer. By mid-June, the flowers start to die back and sweet pea pods appear on the vine. You can continue harvesting sweet pea seeds as long as flowers are blooming and producing seed pods.
Sweet pea pods look a lot like edible garden peas, but don’t toss them into a salad! Unlike their tasty cousins, sweet peas are toxic. So instead, think about harvesting seeds to grow next year in your flower garden.
Don’t be in a hurry to harvest your pods. Harvesting too early is one of the most common seed saving mistakes. If you harvest the sweet pea seedpods before they are completely mature, they won’t germinate.
After seed pods start to turn brown, check them often. Wait until the pods dry out and start to crack. Then as soon as the pods begin to split, pick them right away. Clip off the individual pods or the entire vine. If you wait too long, the brittle seed pods will break open and drop their seeds to the ground.
Now if you want to replant sweet peas in the same location they are growing this year, then letting seeds fall to the ground is fine. Let pods ripen on the vine and then spill their seeds on the soil. They’ll grow the following spring with no need for you to replant.
However, there is the chance that some hungry bird or animal may eat your sweet pea seeds before they sprout. If you want more control, then harvest pods before they burst.
How to Collect Sweet Pea Seeds
If you want to plant sweet peas in another location or share your seeds with a friend, follow these easy instructions to collect seeds for next season.
Select a few beautiful, robust plants and stop deadheading them. The seedpods won’t begin to form until after the flower dies, so the flowers must remain on the plant until they are dead. Tend to the rest of the plants in the garden as usual, pinching out sweet peas and deadheading flowers to keep them blooming freely all spring and into summer.
As sweet pea seed pods begin to dry and crack, you can either cut individual pods off the vines or cut down entire vines with the seed pods still attached. Use a pair of sharp pruners, like these precise micro-tip pruning scissors from Fiskars on Amazon, to make the task easy.
The next step is to remove the seeds from the pods. This is called threshing. Place the dried seed pods (or the vines with seed pods attached) in a paper sack, like these small brown paper bags from Amazon. At that point, shake or best the bag to loosen the seeds from the pods. Then pick out the vines and any large sections of seed pods from the bag.
Getting the seeds clear of the remaining seed pod debris in the bag is called winnowing. You’ll need two buckets and a box fan. Pour all of the seed and pod material left in the bag into one bucket, set up the box fan, and pour the seeds from one bucket into the other in front of the fan. Seeds are heavier than the chaff and will fall into the bucket, while the lighter chaff blows away.
If you’re limited on space or worried about the mess that can arise from winnowing, you can also use a metal sieve, like this one from Amazon, to separate sweet pea seeds from the chaff.
How to Save Sweet Pea Seeds to Plant Later
It’s easy to save your harvested seeds so that you can plant them at a later time. First, allow the seeds to dry on a flat surface for a few days, then pour them into a glass jar with a lid.
Or use paper seed envelopes, like these ones from Amazon, to allow your seeds to breathe and prevent mold. Store seeds from your garden somewhere dry and cool over fall and winter.
Frequently Asked Questions
How do I know when my sweet peas are ready to harvest?
Harvest seed pods once they are dry and start to crack. Do not harvest early since the seeds will not continue to mature once you remove the pods from the vine.
How do you know if sweet pea seeds are viable?
There are few different seed viability tests you can do before planting sweet pea seeds. The quickest and easiest way is to place your seeds in a glass of water. If the seeds sink, they are viable. If they float, they probably won’t germinate.
For more reliable results, place seeds on several layers of moist paper towels. Roll up the towels loosely and stash in a plastic bag. Leave the bag in a warm spot and observe how many of them germinate.
