Growing Catalpa Trees From Seed - Fall Pod Havesting - December 2021
In our backyard, we have a couple of mature (and a few smaller, understory) Catalpa trees. I've posted about them from time-to-time and talked about how I've come around on them and have grown to really enjoy the species. And how the Catalpa tree has become a sort-of gateway into the whole "Native Tree" world. This Spring, we came across some Kentucky Coffee Tree seed pods at a Downers Grove park and successfully germinated them and grew some seedlings. We're currently attempting to overwinter those tiny seedlings by digging their containers in the ground. What I've learned from those seedlings was that the seeds required a winter rest. Or...what they call stratification. That means that they require a period of dormancy that comes along with the cold temperatures of Winter. For the Kentucky Coffee tree, that happens with the seed pods hanging on the trees all Winter until Spring when they drop.
Based on that experience, I've decided to try my hand at growing Catalpa trees from seed. But, I'm actually unsure of how to go about it. From what I've read, the Catalpa tree seeds are similar to the Kentucky Coffee Tree seeds in that it is best to keep the seeds in the pods all Winter. But, what (at least for our yard) is different is that the Catalpa trees we have began to drop their seed pods already. Not all of them. But, some of them.
Thus, I'm taking an approach that is four-fold:
1. Leaving the seed pods that are still on the tree to stay all Winter. And, come late Winter/early Spring, collect the pods then.
2. I've picked up the pods that fell and cracked them open to harvest the seeds. Planting them in the ground RIGHT NOW to see if they'll germinate come Spring.
3. Similar to #2, but instead of being in the ground, I'm going to put them in a container. A large container.
4. Collecting the seed pods that feel, but leaving them closed and simply storing the pods outside in a spot that seems like critters won't get to (in this case, under our patio furniture cover). I'll then grab them when the weather turns Spring and plant them in small nursery pots similar to the Kentucky Coffee Tree seeds from last Spring.
The photos below show #2, #3 and #4. First, a look at the pods and how they've turned light brown. In my hand below is one pod that I cracked open. And a few that I stuck on the table for winter storage.
Before I started this, I went on YouTube to try to figure out what the right thing to do is with Catalpas. There doesn't seem to be a grower in my Northern USDA zone, but this guy on YouTube has a really nice video that shows off the steps. That's also where I first was shown what the seeds actually are. They're these little white things with wings. The seed is in the middle, but the 'wings' allow for the seed to scatter. Kinda genius, right? See below for some of the seeds that I pulled out of one half of the pod. There are dozens of seeds in each long, slender seed pod:
I put a couple of seeds in each little trench that I dug. Below you can see the twelve-or-so seeds that I put down. They're about six to eight inches from the fence. And run from the 3rd full fence board from the hydrant to the eighth.