Air Layering

This morning we spent more time in the nursery trimming gracilis for sale and learning more about air layering. Air layering is a technique best used when the plant you’re trying to propagate doesn’t graft well or produce viable seeds. While you can air layer any plant, it works better for some than others. Lychees are often propagated using air layering, as is our favorite, Amherstia nobilis. Our demo model was a Rainbow Shower tree, also known as Cassia fistula x javanica.

The method for air layering a tree is a bit different from bamboo. First, we girdle the bark, cutting away around a half-inch of the bark surrounding a suitably sized branch.  Then, keeping with the organic status of our farm, we sometimes add kelp powder, which has most of the same nutrients and hormones as a rooting hormone mix, but still fits under organic standards. We then wrap the area with wet sphagnum moss and surround the mass with tin foil (we find it’s the only material that doesn’t degrade quickly under the sun). With a decent amount of rainfall, the branch will start sprouting its own roots in a few months.

All photos © 2010 Dan Bloch

air layering

Today we worked in the nursery learning new propagation techniques with Bambusa chungii, focusing on air layering. Air layering is a method used to sprout new roots from the bamboo culm itself, rather than from the root system. First you top (cut the tops off) the bamboo and cut back all the new shoots. Wait a few weeks and then come back to check if new branching has happened below the cut top. If so, then wrap the new branches with sphagnum moss, thoroughly soak with water, and wrap with tin foil. Leave the bottom tight and the top slightly open to collect rainwater.

With any luck, you should see some new root growth after a few months to two years (it depends on the rain, sun, and nutrients). Then cut down the culm below the moss/tin foil blob, trim the new branches that have their own root growth, and repot, making sure to trim extra leaf and branch growth, since the new roots can’t support too much greenery.

After repotting the air layered chungii, we returned to our B. textillis Gracillis from last week and trimmed extra branch growth, to keep from overtaxing the roots.

We also dug up some Gigantochloa atroviolacea, one of our beautiful black bamboos, that was taking over the nursery, while our culinary specialists climbed up a starfruit tree to harvest lunch.

All photos © 2010 Dan Bloch