A couple of weeks ago, I started growing my seeds inside. Over the years, I have discovered that not all seeds are alike. Certain seeds need to be scarified, stratified, soaked, or inoculated. I will be focusing on seed scarification for this article and will touch upon the other methods in future articles.
I grow many plants (including perennials and flowers) from seeds since it is cheaper and more rewarding than buying them at the garden store. In order for me to be successful, I need to know how to germinate the seeds.
As I mentioned above, some seeds need scarification.
What is seed scarification?
Doesn’t the words, seed scarification sound scary? The word seems right out of a Freddie the 13th movie! Scarification means that you need to roughen up the seed by using a nail file or sandpaper. (And no, it doesn’t mean to send Tony Soprano’s “boys” to shake up the seeds.)
Why do some seeds need scarification?
Some seed coats are impervious to water. It is nature’s way of protecting the seed during dormancy. Fall planted seeds that go through a freeze/thaw cycle or pass through the digestive system of an animal naturally scarify. Did you ever notice how seeds just pop up in your garden? Thank the birds.
Helping Mother Nature to germinate certain seeds.
So how can we help nature to break the seeds’ dormancy?
According to the North Carolina Cooperative Extension Service, there are several ways you can scarify your seeds:
“For mechanical scarification, seed coats can also be filed with a metal file, rubbed with sandpaper, nicked with a knife, or 2 cracked gently with a hammer to weaken the seed coat. Another method is hot water scarification. Bring water to a boil (212°F), remove the pot from the stove, and place the seeds into the water. Allow the seeds to soak until the water cools to room temperature. Remove the seeds from the water and sow. Following scarification, the seeds should be dull.”
If you want to learn how to grow trees through this method, read here. I had no idea you could grow crab apples, Holly, and oak trees from seed.
The Lady Bird JohnsonWildflower Center adds the following seed scarification suggestions:
- Rub the seed with sandpaper. (I have done this.)
- Freeze the seeds overnight and then soak at room temperature for several days.
- Freeze the seeds overnight and then put them in boiling water and let them sit in the water for several hours. (Be sure to watch the video below regarding the results using boiling water.)
You can use a microplane grater as well to scratch the seeds.
Some commercial growers use sulfuric acid. I won’t try this method.
Seeds that will need scarification:
- Nasturtiums (pictured above.)
- Morning Glories
- Moon Flowers.
- Flowers or perennial seeds that are large. (Beans are large seeds but don’t need to be scarified. It will help them to germinate quicker but not necessary.)
See this list that identifies which plants needs certain germination requirements including scarification.
Tricia from Peaceful Valley suggests soaking perennial seeds overnight. If they swell, then they don’t need scarification.
Vegetable seeds don’t need scarification unless you want to germinate the seeds quickly. I wouldn’t suggest this unless you give them a light sanding. You don’t want to harm the seeds.
Be sure to watch the below video which shows several ways to scarify seeds, as well as the results. He is using beans which wouldn’t be my first choice to show on a video. Beans grow so well by themselves.
Note, if you do nick the seeds, plant them right away.
Join the Conversation:
Do you use seed scarification in germinating your seeds and if so, which ones?
Next up. Learn how seed stratification helps in germination.
Disclaimer: There may be affiliate links in the post. I make a small commission from your purchases.
green Bean says
Wow! This is so helpful. I am totally pinning this and going to have to refer back. I’ve done cold stratification (is that the right term) for milkweed and perennial flower seeds but I confess to being usually too lazy to do all this other stuff. That said, I’ve not had a lot of luck with germinating lately and this may be why.
Lisa Sharp says
Wow, I had no idea, thanks for the info.
linda spiker says
Lol I had never heard of scarification! I learned my new thing for the day!
Anna@Green Talk says
Linda, the word for today! Anna
Megan Stevens says
I love Nasturtiums so this is really good to know. I had no idea.
Anna@Green Talk says
Megan, I could never figure out why some wouldn’t’ germinate. Now I know. Anna
karen says
LOL….”Freddie the 13th movie” You mean, “Friday the 13th” movie? (I couldn’t help it. See? I read your entire post!)
I guess some seeds are like us….They need their ass kicked into gear!
Thanks for these great tips! Can’t wait to kick some seed butts soon!
Anna@Green Talk says
Karen, I am getting my horror movies mixed up. Yeah, you actually read post rather than someone who know who skims them. Who would that be? Anna
Frank Rosinski says
I found by accident that the tree “Black Locust” (which is in the legume family and puts nitrogen into the soil) requires scarification. I had a small bonfire burning black berry brambles and some black locust leaves, sticks, and seed pods were raked into the fire also. Not too long after, the trees sprouted in the spot of the fire. Thanks for your article, I learned a lot.
Anna says
Frank, I was just learning about another seed that you had to burn too. Very interesting. Anna