By Payton Tholstrup
Image courtesy of Canva
With spring on the way, gardeners are getting seeds ready for planting and one question comes up often: how long do seeds last?
Josh Wisner, owner of Wisner’s Greenhouse Project at 23rd & Elk in Clay Center, said it depends on the seed and how they are stored. Seeds can last from a year up to 5+ years.
“Parsnips for example don’t last long. I don’t know how many people plant parsnips, but if you have that seed, don’t hang onto it. Plant it. Watermelon or tomato seeds can last years and years if you keep them in a cool and dry place,” said Wisner.
To properly store seeds, they need to be fully dry; store bought seeds should already be dry. Then, the seeds should be placed in an airtight container, like a glass jar or a Ziploc bag.
“They should be kept in a cool, dark, dry place. This could be a basement or if you have extra space in a refrigerator, that is a great spot to keep seeds.”
If seeds are shriveled, that is a good indication they have gone bad. If they have mold, Wisner said that is a dead giveaway.
If it isn’t obvious, or you are just unsure, he suggested getting a wet paper towel and placing ten seeds on it. Then, put all of it into a Ziploc bag. Watch it for a couple days to a week and see if the seeds germinate.
“You can see how many germinate out of ten, and that’s your germination rate. Five out of ten is a 50% germination rate. If you are doubtful that your seeds are good, you can over sow and see what you get. If more germinate than needed, you can just pluck them out later. I know that’s hard to do,” he said.
When deciding whether to get new seeds or plant what you already have, Wisner said it truly just depends on the seed and how much you’re depending on them to pop up.
“If you really need that tomato, perhaps it’s better to buy new seed. If they are some old flower seeds, just toss them in your garden and see what pops up!”
As for when to plant seeds, the answer is once again that it depends.
“It depends on what seed you are sowing and what you have available to keep them happy until planting time. Look at your seed packet and see what is recommended. Some seed packets will say plant 6-8 weeks before your last frost,” Wisner said.
On average, the last frost date is April 25th. For seedlings, a grow light or shop light will be needed until planting time. The light should be placed directly above them, so they don’t get too “leggy” when they pop up out of the soil.
“I have my grow lights already turned on so that as soon as they pop out of the soil, they are getting the light they need. You will also need to keep them watered so they don’t dry out.”
Because the 25th of April is the average last frost date, it’s important to keep an eye on the weather. If you want to avoid the cold altogether, it’s best to just wait until temperatures start warming up.
For plants that don’t need cold temperatures to germinate, such as some perennials or flowers, you can sow them outside right now.
“If you want to keep an eye on them and not just scatter them on the ground, you can use the milk jug winter sowing method. Look that up on YouTube and you will find lots of helpful information there. You can also do a method of germination in the fridge, but I don’t usually mess with that.”
If you have seeds that aren’t in a packet and you’re unsure what they need, Wisner said Google the seed name and the phrase “seed germination needs.”
“The internet will generally give you good advice for what the seed needs to germinate. Give it a try!”
