When making cuttings of young pine seedlings – seedling cuttings – it’s important to use a potting medium that retains moisture. An easy way to achieve this is by using a potting medium like sand. Its small particles retain moisture and enough air for new roots to develop.
Although fine sand particles are good for developing new roots, they don’t provide the drainage the cuttings will need once new roots are established. For this reason it’s common to use several grades of soil when planting seedling cuttings.
In the past, I’ve used a solid cylinder to make a crater into which I pour sand that will keep cuttings moist. At a recent Bay Island Bonsai meeting, I learned a crafty technique that makes the process easier. I begin by filling a small plastic pot about half way full of bonsai soil. I then set an open cylinder, a section of 3/4″ irrigation pipe in this case, on top of the soil.
Plastic pot, bonsai soil, PVC cylinder
I then add more bonsai soil around the cylinder.
Pot filled with bonsai soil
Next, I fill the cylinder with sand and then remove it.
Cylinder filled with sand
After removing the cylinder
I’d prefer to use a larger grade of sand, but fine is all I have right now. As an experiment, I replaced the sand with very fine akadama particles, the result of sifting through akadama “dust” with a very fine sieve.
Fine akadama particles
3″ pot with fine akadama
After filling the pots with soil, I watered them and poked a very small hole for the cuttings. I made the cuttings, applied root hormone, dropped them into place, and then watered them again (see “How to create seedling cuttings” for details).
Cutting in fine akadama
To preserve additional moisture, I added a little sand on top of the akadama.
Sand sprinkled on fine akadama
I used individual pots for my red pine seedling cuttings because only a few were mature enough to make the cuttings. Far more of my black pine seedlings were ready. Instead of planting these into individual containers as I usually do, I planted them in rows in a larger pot. Two of the rows are planted in sand and two in fine akadama covered with a little sand.
Seedling cuttings in terra cotta pot
Once the cuttings root, I’ll repot them into individual containers and start fertilizing. Until then, I’ll keep them under shade cloth with my other cuttings.
Cuttings in the shade
The first time I made seedling cuttings I created a mini-hot house to maintain humidity while the cuttings rooted. It was essentially a plastic box I set over the pots with the cuttings. Now that I have a watering system, I leave the cuttings in the open so the system can keep them moist. In the future, I may create a box with a mister inside to keep the humidity even higher.