Cold Stratification

It's been several weeks since any of my remaining sequoia seeds have germinated in their damp coffee filter baggies. Of the sixteen germinated seeds, I'm down to only six that are still alive. Most recently, my first sprout, seed #1 just shriveled up and died. As silly as it sounds, that really brought me down.

So, I'm down to six sprouts and about eighty seeds. I can either throw out the seeds, buy more and start over, or I can try to turn around the seeds I have and see if I can get them to sprout.

It's likely that a third of those seeds are still viable, but dormant. In nature, conifers have a clever trick to avoid entire crops of seedlings to dying off in a catastrophe such as fire or drought...they don't all sprout at the same time. One way to break this dormancy is to mimic natural conditions that the seeds would go through, such as winter coldness. This is called cold stratification, and can be achieved by placing the seeds in moist peat moss (or other mixtures) in a refrigerator at a few degrees above freezing for one to three months.

Note: this isn't normally necessary for vegetable and flower seeds, since they've been cultivated to grow without the dormancy. For more information and other seed-starting tips, I highly recommend the following links: Seed Germination and Growing Conifers From Seed.

I split out my seeds into two groups, then dropped them into sealed baggies, each with a few tablespoons of seed starting soil mix. I sprayed spring water into the baggies until the soil mixture was moist, and stored them away in the back of my refrigerator.

Waiting two months isn't going to be easy, but it'll be interesting to see the difference that cold stratification makes. After that time, I'll probably keep the seeds in the baggies until they've sprouted, then move the individual sprouts into cel-packs. The coffee filter baggies worked really well, but only for the initially-sprouting seeds. After a couple of months, it's hard to stave off mold and frustrating keeping the baggies moist.

More Mold! (No Problem)

For the past month, I've had between fifteen and one-hundred fifteen giant sequoia seeds sitting in damp coffee filters in the dark. I realize now that there's no guaranteed way to prevent mold growth, so rather than freak out, I spent tonight cleaning all of my seeds, and transplanting them in new coffee filter baggies.

I found the best way to do this was to place the seeds in a metal vegetable strainer with very fine holes (less than 1mm square), and run room-temperature water through them. For the few seeds that had a decent build-up of mold, I carefully gave them a little rub, and more water. I used toothpicks to help maneuver the seeds, discarding them after touching dirty ones. I didn't want to waste my time cleaning the seeds, only to give them back their mold afterwards.

Once the seeds are in the soil and sprout, the air circulation should help prevent mold problems at that point. My goal is to keep them as clean as I can until then, then make sure to remove the seedlings from the greenhouse as soon as they sprout. With germination taking anywhere from seven to ninety days, the baggie method really helps fight mold. If I had planted the seeds in soil from day one, there would have been a serious mold problem in the greenhouse pretty early on.

Mold!

Everything I've about growing giant sequoias from seeds says to watch out for grey mold. Well, when looking through the baggie seeds, I noticed something that concerned me. This is what was I found when I opened the coffee filter...

I'm not sure exactly what type of mold this is, but it concerned me enough to discard this seed and transplant the clean seeds to a new filter and baggie. Hopefully this didn't spread to any of the others. It's a good thing that I had split all my seeds into several bags in the first place. And, since I found this while still in the baggie, this mold won't make it to my greenhouse.

Getting Started...

Most of the reading out there tells you about the trees in the wild, out in California. I had a hard time finding a good how-to out there for growing these trees from seeds on your own. Then I found Shoot's Blog, Growing giant sequoias in pots. In his post, he describes in pretty good detail how to germinate the seeds, grow them in cel-packs, and move them into pots as they get bigger.

It seemed doable, so I ordered seeds from two places, the first 15 from the Catalpa Tree Seed Company through LocalHarvest for $13. After doing some more shopping, I found these to be really expensive. I tried canceling the order, but was too late. Their customer service offered to refund the cost and said not to worry about shipping the seeds back. So, for customer service, they're great. In a few months I'll be able to see if they're worth the high cost, but in the meantime, I bought 100 seeds from the Whatcom Seed Company for about $7.

Following Shoot's Blog post, I first soaked the seeds in a glass of water overnight, then put them in a damp, unbleached coffee filter in a ziplock bag, and kept them in the dark. For my first batch, I left the seeds to sit on top of the water. In my next batch, I folded them up in a coffee filter, and made sure they were underwater all night, not just sitting on top like in the above photo.