Can Garden Seeds Be Frozen?
Storing leftover garden seeds is a great way to be self-sufficient, save money and preserve your seeds for the next season or even longer. The key to maintaining the integrity of your seeds over an extended period is proper storage, and freezing your seeds can be an effective strategy for prolonging their lifespan.
Can Garden Seeds Be Frozen? Freezing garden seeds is an excellent method of storing seeds for the long haul. Not only does freezing help seeds extend their shelf life, but some seed varieties actually suggest it in order to germinate the seeds better. So long as you store the seeds properly, they can still germinate and grow once thawed, with the expectation of recalcitrant seeds.
In this article, we’ll discuss how to freeze garden seeds, how long they can last in the freezer and how to thaw, germinate and plant frozen seeds.
Disclaimer: This article includes affiliate links. If you click one of them, we may receive a small percentage of the sale at no extra cost to you. Thank you for your support!
Table Of Contents
- How To Freeze Seeds
- How Long Do Seeds Last In The Freezer?
- Will Seeds Germinate After Being Frozen?
- How To Thaw Frozen Seeds For Planting
- Which Seeds Cannot Be Frozen?
How To Freeze Seeds
To correctly store garden seeds in the freezer, there are a few things you will need to do. The first is to ensure the seeds are completely dry before storing them. This is one of the most important steps, as humidity and moisture can affect the longevity of the seeds as well as cause them to crack or split when stored in the freezer.
The best way to dry seeds is to allow them to dry naturally. Spread seeds out on a baking sheet or newspaper, leaving space between each seed so they are not touching. This allows for air to reach each seed. After one week, gently move the seeds around with your finger, then let them dry for another two to three weeks.
Another method is to place the seeds in a sealed jar with a silica gel package for one to two weeks—Silica gel works by drawing out and absorbing moisture from the air. You often find these in purses and online order packages. After a week or two, remove the silica gel.
After the seeds have been dried, transfer them into either an airtight container or freezer bag and store them in the freezer. A helpful tip is to label and date each container to avoid any mix-ups when it comes time to thaw your seeds.
How Long Do Seeds Last In The Freezer
Seeds can last between three to five years in the freezer as long as they are completely dried before storing. Hardy vegetable seeds could last even longer as they are more resilient to colder temperatures. Even seed banks freeze their seeds for long-term storage, though they are under better-controlled environments than our freezers at home. It will still do the trick if you only plan to keep them stored for a few years.
Will Seeds Germinate After Being Frozen?
Seeds will germinate after being frozen. In fact, some seeds will germinate better after freezing as this simulates the natural conditions the seeds would experience if planted over the winter. However, you may run into some issues if they are correctly stored in the freezer.
Some seed varietals require exposure to cold temperatures before planting. This is called cold stratification. This process puts the seeds in a dormant state and helps improve their germination rate. While most vegetable crops do not need stratification, many flowers, trees and medicinal herbs will benefit. Here are a few examples of seeds that require cold stratification: Lupine, Milkweed, St. John’s Wort, Morning Glory, Sweet Pea and Perennial Sunflowers.
How To Thaw Frozen Seeds For Planting
As you can imagine, letting your frozen seeds thaw before you begin planting them is important. To do this, take the seeds out of the freezer and let them sit at room temperature for around 24 to 48 hours. Once they are no longer frozen, you can either begin to germinate or directly sow them, depending on the type of seed.
Which Seeds Cannot Be Frozen?
While many seeds can be frozen, recalcitrant seeds cannot be. These seeds cannot be dried below relatively critical moisture levels, nor can they handle temperatures below 50 °F (10 °C). In addition, they cannot be stored for long periods as they germinate quickly, making it best to use them fresh to ensure viability. Recalcitrant seeds include mango, lychee, coffee, avocado, sweet chestnut and cocoa.
