Many folks root plumerias by starting them off in a plastic bag. One of the main advantages of bag rooting is that space is saved. A bag takes up much less space than a one-gallon pot. Also, as most folks use a heating mat, concentrated heat can get to the root ball to improve the rooting results. I got the idea of using a burlap bag instead of a plastic bag from Thomas Cox. Advantages of the burlap bag are: 1) Once there are roots showing, the burlap bag can be planted in a pot and the burlap disintegrates; and 2) Using burlap means I don’t have to fuss with getting the plastic bag off the rootball without breaking fragile roots. Below are the steps to burlap bag rooting a plumeria.
Step 1
Begin the process of rooting a plumeria in a burlap bag by cutting a piece of burlap approximately 5″ x 5″. I buy my burlap at a big box store. It comes on a roll and has a very lose weave. A lose weave is desirable so the roots can grow through the burlap; also, a loosely-woven burlap breaks down very quickly after the rooted cutting is planted.
Step 2
Place a handful of coir on the piece of burlap. I use good-quality coir purchased at my local hydroponic store. It is premoistened and has just the right amount of moisture. If using dry coir, reconstitute with water, and squeeze out as much moisture as possible. Good-quality coir has the salts washed out and is treated with nutrients. Peat moss works well too.
Step 3
The next step is wrapping the piece of burlap around the plumeria stem. This can be tricky to do if you tend to be all thumbs, but possible.
Step 4
This is how your burlap bag should look.
Step 5
Have a 12″ – 16″ piece of electrical tape on the ready and wrap it around the stem–some of the electrical tape should be on the burlap and some on the plumeria stem so the wrap is secure and there is no slippage.
Step 6
Next, place a plastic bag over the burlap bag and secure with a short piece of electrical tape. I prefer using a plastic bag with some thickness to it as it holds in moisture better, but a thin sandwich bag will work fine.
Step 7
Place your bagged cutting in your favorite rooting spot. Most of mine go into a plastic tub which sits on a heat mat set at 80 degrees. The tub and heat mat are inside a small greenhouse. If it’s a large cutting, say 4′ – 5′, I often rest the cutting next to the house. In all cases, the cutting is not exposed to full sun. In time, roots will appear poking through the burlap.
Step 8
At this point, I pot up the cutting. This photo shows the burlap bag with the plastic bag removed. If I we’re to wait for more root growth, the roots would be damaged in potting up.
Step 9
Next is the removal of the electrical tape. Hold the burlap bag when doing this so that the burlap bag doesn’t fall apart or pull off the tender, new roots. Have your pot ready with your mix in place about 5″ below the rim of the pot. Lower the burlap bag to the mix.
Step 10
Fill in around the burlap with your mix. I use a mix of 50% coir and 50% perlite. The roots grow very quickly in this light mix.
And this is the new plumeria with roots intact and already growing, ready to thrive. I use foam to brace the cutting so there is no movement (and no broken roots). Stakes could also be used.
Plumeria Propagation – Cutting, Rooted or Grafted 
Michele’s Bag Rooting Method 
What I use a greenhouse for 
How to Grow Plumeria from Cuttings 
Understanding Plumeria’s Seasonal Cycles 
Why are Plumeria Seedlings so Different? 
Mealy Bugs Plumeria Pests 
Known Plumeria Names