One of my favorite tender bulbs to grow is Eucomis bicolor. The bulb is commonly called a Pineapple Lily because the cluster of flowers grow in a pattern that resemble a pineapple. If you are interested in information on how I grow these bulbs here in Chicago you can read my previous post at this link: Eucomis bicolor-Pineapple Lily.
Like with a lot of bulbs you plant in your garden Pineapple Lily can be propagated by removing offsets or collectings seeds but you can also propagate Eucomis bulbs by taking leaf cuttings. The most important part of the process is making sure you take your cuttings during the spring or summer to allow for the formation of the bulbs. Cuttings taken too late in the season will probably not produce any bulbs and you'll end up with rotted leaves. Propagating this plant is very easy and I'll try to explain how to do it here.
Remove a healthy green leaf from the bulb at the base of the stalk. I find it works better if you take your leaf after you've watered or after it has rained in your garden because wilted or blemished leaves don't work as well.
While wearing gloves take a sharp pair of scissors or a knife and make horizontal cuts across the leaf like in the image above. I used a hobby knife that I bought at a 99 cents store that I use for propagating plants but you can use whatever you have handy that is clean and sharp. Once you've made your cuts across the leaf of the Pineapple Lily leaf make sure to keep them facing the direction that it was growing on the plant. If you want you can set the cuttings to the side for an hour to allow them to dry. When you make your cuts you'll notice a clear gel-like substance leaking from the cut edges similar to the gel inside an Aloe Vera leaf. I don't know if it is toxic or harmful in some way but if you're wearing gloves you shouldn't be in any danger.
After you've made your cuttings you can dust the cut ends with a rooting hormone before you insert the leaf sections into your favorite rooting medium. I just used regular potting soil but use what you are already familiar with and have handy as long as you don't try to root them in water. Once you've inserted your cuttings into your rooting medium and have moistened the soil you can set them in a bright area that is protected from direct sun. After a few weeks you should find that your leaf cuttings are producing bulbs along the edge of where you've made your cuts.
Many hobby plant propagators will usually cover their cuttings with a plastic bag to keep them from drying out or they'll mist frequently and remove the bag to check the moisture of the soil. I personally don't like the plastic bag trick because if the bag comes into contact with the plant, leaf or stem inside- you'll end up with rotted plant material. What I like to do (and did in this) case is take a 2 liter soda bottle and cut in half just like if I was making a Bio Dome Seed-Starter. Because the sides of the soda bottle are stiff I don't have to worry about them accidentally coming into contact with the cuttings inside and I find that it traps enough humidity so I don't have to check regularly on the soil after the initial watering.