If you are like most gardeners who grow vegetables from seeds, there are always some seeds leftover after sowing. These extra seeds are often stored in the packet they came in and tucked away in a drawer or box to be used the following year - or the year after that, or...
The process can quickly get out of hand as each year’s new purchases are added to the hoard. Who can resist all the new varieties that promise sublime taste, disease resistance, and higher yield? We can’t!
So, how can you tell if a packet of seeds is still good? The long winter months are a perfect time to gather up all leftover seeds and do a little sorting, testing and purging. It can be a great activity for a particularly cold and dreary day to help remember the warm sunshine of summer.
In general, seeds can last 2-5ish years, depending on the variety and the storage method. Certain seeds, like onions, are only good for one year. Johnny’s Selected Seeds’ website has a handy chart with life expectancy of a plethora of seeds. We use their seeds in all of our Garden in a Box and Spring Gift bundles - they are great!
It also really matters how the seeds are stored. Johnny’s suggests putting them in glass jars with a desiccant and storing them in your refrigerator. If you don’t have extra space in your fridge, consider using glass jars (old baby food ones work great) stored in shoeboxes in the coolest, driest place in your home.
Here are the steps to test if a packet of seeds will still germinate. It can be a fun experiment to get the kids involved in.
You will need the following supplies: Paper towels, water, seeds in question, plastic bag or large lidded glass jar/terrarium, paper and marker.
- Place several seeds between two damp paper towels
- Enclose in a plastic bag or large glass jar or terrarium and place in a sunny warm window
- Mark on the bag or note on paper which seeds, date, #of seeds etc.
- Check on them after several days to see if any of the seeds germinated. Note that some seeds can take awhile to germinate.
- Count how many seeds germinated and then figure out the percentage of the total. For example, if you used 5 seeds and 4 germinated that would be 80% - meaning the seeds are still good. If only 1 germinated, which is only 20%, it might be time to pitch those seeds.
If you don’t want to experiment, you can also just start more seeds than you need, knowing that some just won’t germinate. Even some really old seeds will germinate, but they might not produce the most robust plants.
A best practice is to only buy what you need for each season, which is very hard to do unless you have a very large garden - some packets come with 100+ seeds in them! Consider a seed swap with other local gardeners. The tremendous growth in people vegetable gardening, combined with suppliers selling out of seeds, means there are sure to be lots of people who can put them to good use.
If you have a Tertill weeding robot in your garden, be sure to use the supplied plant guards to protect young seedlings until they are about 4-inches tall. Watch the video on how to use them on our How To Page.
So gather up all those seeds and start sorting through them. If you choose to cold compost the old ones, you might get some bonus vegetables growing on your compost pile!