Rewilding My Lot

UPDATE: The effort described in this post had zero success. See this more recent post for a different approach and better outcome: https://rewildingmylot.blog/2024/08/01/germinating-texas-mountain-laurel-seeds/

Seeds of the Texas Mountain Laurel tree are remarkably robust. Once they fall from the tree, it can take up to ten years until germination, but I didn’t want to wait that long. I was gifted the opportunity to harvest seeds from a friend’s mature tree, and here’s what I learned along the way.

The pod on the left of this photo is how they appear on the trees right now (July in Seguin, Texas). If you want to open them up at this point, you need a strong cutting tool and you have to be careful that you don’t slice the seeds in the process.

Once the pods drop from the tree, then the outer layer thins and softens as it lays on the ground. It was easy to break open the pods that had fallen to reveal the seeds inside. The photo also shows seeds on the right and pod skins in the middle (glove for scale!).

But that’s only the first part of the process. The seeds have a hard outer coating that needs to be broken before germination can start (to admit water and oxygen).

Scratching or cracking a seed to allow germination is called scarification. In nature, that would primarily occur by temperature fluctuation cycles (freeze/thaw), or by animal or bird intervention during eating and elimination.

The Texas Mountain Laurel seeds were so hard and slippery that I had to try several approaches before I was successful, also aiming not to damage fingers in the process. What eventually worked was to hold each seed with pliers and then to gently rotate a hand pruner around the edge of the seed until there was a crack. In some cases, a small piece of the casing fell off. Once I saw how thick the seed casing was, it was clear why my initial sandpaper approach was useless. Inside the outer red shell, the seed inside is pale and soft.

Then the seeds went into water to soak overnight. Of the six seeds I had at this point, one floated and the others sank to the bottom. I don’t know if that’s significant. After the overnight soak, the “floater” was harder and darker than the others (on the right in the photo below).

The next morning I planted the seeds. The primary purpose of this activity was to provide back-up for my ailing young tree in case one significant branch later dies. If that happens, a seedling from underneath could grow up to provide some symmetry. See earlier posts: What Is Wrong With My Texas Mountain Laurel Tree? and More Treatment Of The Texas Mountain Laurel

However, I also have enough seeds to start some in pots to plant elsewhere or as a second back-up in case the first in-ground approach doesn’t work. I have no idea what my germination success rate will be.

Three seeds went under the Texas Mountain Laurel tree, pushed into the ground no more than one inch. One of those was the floating one (closest to the tree). The other three seeds went into a pot (I didn’t have three small pots, so for now I have subdivided one larger pot with cardboard to stop roots getting tangled up).

And now we wait!