Because squirrels are endowed with peanut sized brains, walnuts are given a crack at life. Squirrels, you see, have limited memories. They don’t remember where they put all their autumn buried nuts and therefore don’t eat them all during the winter. These forgotten nuts are enabled to sprout and make their bid for treedom when spring rolls around. It is believed that most walnut trees get their start this way.
Sometime last autumn my local A.D. D. Fox Squirrel decided to bury one of his precious walnuts right next to my house foundation and then promptly wiped its location from his memory banks. I discovered the resulting tree sprout a few days ago when trimming around the yard. Unfortunately I had to pull up the ill-placed plant, but saw in its demise an opportunity to talk a bit about tree nuts and germination. Your parents probably never got around to giving you the germination talk did they? Well, it’s high time we got to it.
Take a look at the graphic photo above, and you’ll see the young walnut sprout with its dirty nut still attached. Unlike many plants that actually lift their seeds up into the air when they sprout (like bean sprouts), walnuts leave their nuts in the ground. They are hypogeal germinators. This means that they leave their nuts in the ground -which is what I just told you. What I didn’t tell you is that the inside of the nut – the nut meats – are actually called cotyledons (see here this pinkish heart-shaped structure). The cotyledons provide support for the formation of the main root and the sprout. In this type of germinator the cotyledons are power supply to get things going.
The root, or radicle, busts out of the shell and immediately seeks a downward direction. These cells are wired with a gravity-oriented component that guarantees their mission success. The tap root (see here in broken form) grows deep into the soil and acts as an anchor and feed line for the new tree. Walnuts are able to establish an extremely long tap root in a short order of time.
The other growth coming out of the split nutshell, next to the radicle, is called the epicotyl. This is the part that seeks to fight the forces of gravity as a heaven bound leafy sprout. The sprout generates leaves and the leaves start the photosynthetic process. Walnut seedlings are often able to achieve over 36 inches of new growth within a few months and even more during their second year.
Now, I understand that knowing all of this may not change your life in any significant manner, but it might be a cause for poetic pause next time you see a seedling walnut. Repeat after me: “A squirrel’s nut forgotten is a Walnut tree begotten”. Aren’t you glad we had this little talk?