How to sow fern spores?

Harvest the spores

Although this varies depending on the species, most spores are harvested in late summer or autumn. When the sores are mature, they turn a brown colour. You can then cut a part of the frond and place it in a paper bag. The spores will detach on their own. You can then collect them and sow them. The chances of successful sowing are higher with fresh spores. However, if you prefer to store them for later sowing, place them in the refrigerator in plastic bags to protect them from moisture. They do lose some of their seed viability over time.

Fern spores are located on the underside of the leaves

Sowing fern spores

To sow ferns:

1. Mix potting soil and sand, then sieve to obtain a fine substrate. You can also add turf, which retains moisture.
2. Moisten the substrate.
3. Sterilise it by microwaving for 10 minutes to prevent the appearance of mosses or fungi.
4. Choose a transparent plastic or glass container with a lid (to retain moisture). We recommend cleaning and sterilising it. Fill it with substrate, then lightly compact it.
5. You can now sow the spores by spreading them on the surface. Do not cover them with soil!
6. Place the transparent lid on the tray. This helps maintain a moist and sterile environment.
7. Position your sowing in a bright location, out of direct sunlight.

Although the germination speed varies depending on the species, generally after about a month you will see a green film appear on the surface of the substrate. These are the prothalli, tiny organisms that bear the sexual organs and thus allow fertilisation. At this stage, the substrate must remain moist; you can mist it if it tends to dry out. Then, ferns as we know them will develop from these prothalli.

The first fronds of ferns emerge from the prothalli

When you see the first fronds appear, you can transplant your ferns into individual pots. You will need to wait a year before planting them in your garden.