How to store leftover seeds from the summer garden

With the start of fall, you might be wondering what to do with all your leftover unused seed packets. If you’re anything like us, every spring when the new seed packets arrive, you might buy more than you have space for in your garden. Or, perhaps you bought some new varieties to try out and the seed packets had more seed in them than you were expecting to plant.

To avoid wasting the seed, why not save your unused seed and packets for next year? This will not only save you time, but it will also save you money. And, let’s face it, finding ways to save money will help us all in the long run. In today’s blog post, we give you some important tips to properly store your leftover seed from this year’s garden. By following these tips, you will be well on your way to becoming a successful seed storer.

Selecting seeds that are storage stable

Just like anything, some seeds store better than others. It all depends on the variety. Vegetable seeds with a shorter storage life include corn, spinach, parsnips, parsley, onions, garlic, shallots, and chives. For these seeds, they have the best viability when they are used in the season in which they are purchased, but some may last up to two years if properly stored. If harvesting seeds yourself, these seeds do best when planted in the subsequent season from which they were harvested. Similarly, flower seeds like verbena, phlox, and salvia may only be viable for 1-2 years max. By contrast, vegetable seeds like bush and pole beans, carrots, lettuce, snap and sugar peas, and radishes can last between 3-5 years if properly stored. Similarly, flower seeds like snapdragons, cosmos, sweet William, nasturtium, and zinnias have a longer shelf life and may still be viable between 3-5 years from purchase or collection.

Keeping seeds in a dark, dry, and cool space for proper storage

To properly store seeds for use in a subsequent growing season, make sure that they are kept in a dark, dry, and cool space. Keeping them in these conditions helps to prevent funguses or disease. It also helps the seeds to maintain vital nutrients essential for germination. If possible, try to keep any unused seed in their original packaging with a new seal. This will help to give them the proper dry conditions that they need for successful germination. Keeping them in the original packaging can also help to preserve the labels so that you know what you will be planting next year and the best conditions for growing your seedlings.

Seeds can also be stored in air-tight containers or in new paper envelopes which are then placed into a plastic bag. The goal is always to give your seeds the best place where they will stay dry and moisture-free. If using different containers than the original packaging to store your seeds, be sure to properly label them with essential information. This way, you will know how to use the seeds in subsequent growing seasons.

Seeds should not be stored in direct sunlight as it will interrupt the germination process. They also need to be kept cool to ensure proper germination. Avoid leaving unused seeds in an outdoor garden shed or garage as the conditions in these storage areas can sometimes have too much moisture to ensure proper germination next year. If you are collecting seeds from your garden to plant next year, be sure to make sure they have been properly dried out first before storing them.

How to test the germination rate of unused seeds that have been stored

The easiest way to test if seeds are still viable is to create a test batch to measure the germination rate. Simply take some of your unused seed and germinate them as you would any other seeds that you want to plant in your garden. If you get 50% germination rate or higher, you know that these seeds are still moderately to highly viable for growing in your garden and probably have some life left in them for longer storage.

Anything less than 50%, you may want to consider planting these as soon as possible because their ability to be stored long term is dwindling. If during your test, you discover very low germination, it might be better to buy some new seeds to ensure that you not only have successful germination, but that you are giving your garden the best head start possible to produce viable seedlings.

Shelf life of common vegetable seeds

Although crops can vary in shelf life depending on varieties and storage conditions, the following is a quick reference guide of the average shelf life of some common crops.

2 years: Corn, lettuce, peppers, parsley, parsnip.

3 years: Beans, broccoli, celery, kohlrabi, peas, spinach.

4 years: Beets, cabbage, kale, pumpkin, squash, tomato, turnip, watermelon.

5 years: Brussel sprouts, cucumber, radish, collard greens.

Final thoughts on storing unused seeds

By following the tips provided in today’s blog post, you will be well on your way to successfully storing seeds for next year’s summer garden. Storing your seeds is not only a cost-effective way to plan out next year’s garden, but it can also be a time saver. Until next time gardening friends, always remember to keep your seeds cool, dry, and in a dark space. Happy gardening everyone!