My first gardening job as a kid was to cut back Mom’s sword ferns each year. She had roughly 100+ of them. It was a lot of work but it ended up looking quite lovely once they’d all reemerged again. I never thought about how they were propagated though. They were just there with all of the other native plants. I took them for granted.
When Richie Steffen came to my house to give a talk to the underground Daisy Chain group, he really made me think about the wonders of hybridization. Many fern hybrids created during the Victorian era are long gone now. There are so many possibilities it seemed endless after this event so I decided to collect some spores at Cistus Nursery to see what I could come up with on my own.
Several crops came up, and as they did so I observed them carefully. Sporing requires keen patience and some requisite knowledge as well as an understanding of how to coax fern babies along. After my first successful crops though, I’ve kept at it, and have tried a variety of different things. Each year I experiment with new plants to keep my skills sharp. This process takes a lot of time. At certain points it can feel frustrating, and you might want to just throw your arms up in the air and chuck the container. It’s easy to get the sporelings going, but growing them on has been the greatest challenge for me. You can ignore them initially, but you must keep an eye on them to make sure they don’t die out on you.
Clean containers are a requirement. I personally have fallen in love with the takeout containers of the pandemic. Many restaurants use ones now that are microwave and dishwasher safe. Whenever I can save time by sanitizing in the dishwasher, I’m a happy propagatrix.
As for a soilless medium, I tend to use whatever I have on hand. To be honest, you should sterilize it as well, but I often forget. You can do so in a microwave or oven.
Using a container with a tight lid is also important. You want the spores to be in a very humid environment and you do not want to open the lid frequently since it’s more like a Petri dish and can be contaminated far more easily than other seed trays. This can lead to sudden death so be cautious about sanitizing the area where you’re working.
Since I work with a nurseryman who also collects in the wild, I can collect at the nursery, and after Sean has collected elsewhere, I can prepare the spores after the fronds have been placed between sheets of paper.
(*I do NOT recommend that amateur growers collect in the wild. This honestly requires a license typically and we do this to keep plants in the trade to HELP prevent the poaching of entire plants. If you’re interested in purchasing spores, keep reading. I will get to that below.)
At the nursery, I collect spores as they ripen. Most ferns we grow though are primarily divided since it’s quick and easy, but not all ferns grow quickly.
When you collect in the wild—or even from the garden of a friend—you have to do what you can with what you have at the moment you encounter it. This might mean sowing them immediately, or you may have to press fronds by keeping them warm and dry for a few weeks more in a warm and dry basement.
I can’t say at this point that this part is an easy process. It takes observation and experience to understand when a fern is ready. I’ve collected many myself that ended up being duds. I have also collected from one fern only to have spores from another more weedy one appear. (Spores do float around on the breeze so it makes sense that there would be contamination.) It is not easy to isolate most ferns so you really have to simply wing it and try not to be disappointed if it’s not quite as exciting as you’d wanted it to be when you began.
Once I sow the spores on the surface of the medium I use a water bottle to spray them into the soil. (By the way, the medium is also moistened before I sow the spores.) After that, I slap the lid back on tightly and I wait. I usually leave them in a cool spot for a few weeks with a bit of light. You can stack them in a window and forget them too. It’s oddly that easy but it requires that leap of faith!
In the photos above, the two in the middle show what can happen when your soilless mixture has sphagnum in it. This is not a bad thing to have happen, but to a beginner, it might be frustrating and a bit confusing. Luckily ferns and sphagnum can coexist well together.
Additionally, notice how the gametophytes in the second photo look like liverwort. Folks might be confused by this I’m sure and at this stage the containers might be tossed hastily. But guess what? Before the sporophytes appear, you will have gametophytes. Be patient. Be observant. If you know liverwort, you’ll know it when it hits its next growth stage. Soon you will see antheridial and/or archegonium heads. At that point, you can prick that stuff out, but you need to wait.
If your ferns are to grow successfully, soon you’ll see those little tiny sporophytes. (They’re visible in the 3 photos above and to the right, but they may be difficult to see. The photo with the sphagnum has another kind of Pyrossia, and the photo on the far right is a tree fern.)
These are plugs I spored with spores from the American Fern Society. While many were very successful, I had a lot of spores that spread around, so pricking them out was a bit messier then expected. This Bio Dome system from Park Seed typically works well for me too when I have fewer spores to sow. Since it floats on water it is evenly bottom watered which allows me to spore them and forget.
Lastly, I want to help you to purchase spores by encouraging you to join fern organizations. I usually purchase from the Hardy Fern Foundation and the American Fern Society but remember that you MUST become a member in order to purchase from these groups. Individual collectors, independent growers, public gardens, and others donate their own time to collect and send in these spores and volunteers help to run these spore exchanges. Both are an incredible resource to us all, and we should support them as much as is possible.
I hope that this has helped a little bit. I skimmed over a lot of information but I know it’s available elsewhere and has been provided free online by expert growers if you search around. I’m just a propagator with knowledge acquired over years of practice at my craft at home and in the professional arena.
For a much more thorough description of all of this I recommend this article provided online from the Brooklyn Botanic Garden by Judith Jones of Fancy Fronds Nursery.
Thanks everyone for reading this and if you have any questions, please ask away in the comments section.