Float Testing Acorns for Viability

The majestic oak is one of Tennessee’s most beautiful native trees. It’s also an extremely useful tree for our local wildlife as it can host over 200 species of insects and animals. You can see why you would want to cultivate more oak trees! Recently I gathered some acorns from a nearby tree on our property. The oak tree is right on the line where half of the tree drops seeds onto our property. I believe it may be a black oak tree but I’ll be doing some more investigation to positively identify it.

What is a Float Test?

In order to determine if the acorns are viable we can do a float test. Float tests are often done with larger seeds to help determine viability. If the seeds float in water then they may not be viable. Either the seeds have been partially eaten by a borer or other insect or maybe the seeds have dried out too much and air pockets have been formed within the seed.

Acorns are fairly large seeds and vary in size depending on the variety of the tree. It’s very easy to do gather acorns and do a float test.

How do You Do a Float Test on Acorns?

What do You Need for a Float Test?

All you need for the float test is a container or bucket of water and the acorns!

To perform the float test just put the acorns in a bucket of water. Then give them 24 hours to soak up what water they can. The viable acorns will sink while the one’s that aren’t should float.

After waiting 24 hours discard the floaters and plant the sinkers. It’s that simple!

Is this perfect? It’s probably not 100% perfect but the float test does give you a general idea of the good vs bad seeds. You can check through the sinkers and make sure there aren’t any that have sunk with holes in them.

In my case I had a lot of acorns and I didn’t want to sort through them individual. I would also be happy with a good germination rate and I’m not expecting all of them to grow.

After the Float Test

After the float test I immediately planted the acorns in a large pot and put a mesh cover over it. The cover is to prevent squirrels and chipmunks from digging in the pot. After all there are plenty of acorns for them all over the place, I only took a small portion and ultimately this is for their benefit!

I’ll keep an eye on the container and hopefully when spring comes they will begin to sprout through the soil. Then I’ll repot them individually in containers depending on how much germination we get.

A number of factors can impact germination including the type of tree, the weather conditions we have, and animals or insect damage. We’ll just have to wait and see what we get! That’s why gardening is so fun, experimentation!

Float Testing Acorns Video

Check out the video below to see more on how I did the float test on these acorns.

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