How To Root Hoyas
So you've decided to try your hand at propagating Hoyas, or someone has given you cuttings and you don't know what to do. You may have even heard that Hoyas are really easy to get to root, and if so, you have heard right! Just remember that the best time to root a Hoya cutting is during the warmer months when the plant is actively growing. If you propagate a Hoya during the colder months, or when it is not actively growing, it could take the cuttings even longer to root. Another factor in how long it takes to root is the type of Hoya; some types root quicker than others. On average, you will see new growth within a month or two. There are actually multiple ways that you can root a Hoya cutting, water being one of the most common. I personally don't propagate my cuttings in water, and I will explain why a bit later. Also, I will get into the size of the cutting, and why a single leaf won't do much more than be a zombie.
I should probably warn you, before getting into how big of a cutting you need, that Hoyas bleed. Like a lot. Most of my Hoyas will drip white sap, but some drip clear, which it easier to clean up because it isn't as obvious when it drips all over. This happens when you cut into a Hoya, or even remove a leaf. Also, it is best to take the cutting from a plant that has been watered recently, like that same day. If I receive a cutting in the mail, then I always set it in some water for about an hour to perk it up.
All right, now that I have all of that out of the way, I can get into the cutting size. Always make sure that the cutting is no longer than 6 inches, or 15.24 cm, long or it generally will not root. Plus, if you have a cutting that is longer than that, they you can always cut it and have more than one rooting Hoya. I don't know about you, but I will take more Hoyas. Make sure that the cutting has at least 2 leaves, which means the cutting can even be only an inch long. Never try to root a single leaf, because you will most likely end up with what is called a zombie leaf. Zombie leaves are leaves that put out roots but won't ever grow anything else, so you will be stuck with a rooted leaf and nothing more. This is because you need a bit of the main stem, not just the stem that the leaf is attached to, for a Hoya cutting to grow into something more than just a leaf with roots. After many, many years you may get some growth, but that is very rare. I will go into more depth about this in another post.
After you take your cuttings, remove the bottom leaves, and let the end stop dripping and get dry. You can dip the end in rooting hormone, but apparently I like to live dangerously because I never do, and have yet to have a cutting fail (knock on wood). The potting mix that I use is equal parts soil, perlite, and orchid bark, but you can use any kind of soil that you prefer that drains well. You never want a Hoya to have a soggy bottom. Also, make sure that the pot that you're going to put the cutting into is small. I generally use 2" pots to root my cuttings, but have used bigger if I had a bunch of the same type of cuttings to root. Next I make sure that the potting mix is thoroughly dampened, I used fish tank water to water most of my plants. Then I poke a hole into the mix, I usually just use a bamboo skewer, but really anything will do. After all of that, I just stick the cutting in so the area on the stem where I removed the two bottom leaves is in the potting mix, set it in front of the window, and water about once a week. You don't want the potting mix to stay constantly wet or the cutting will rot, but you need it to stay damp enough that the cutting will root.
Now to get into propagating Hoya cuttings in water and why I am not a fan of it. You can follow the same steps, except when you go to put the cutting in soil, you nix that step and place it in water instead. The upside is that you can actually see the roots forming and growing, which is pretty interesting. The cuttings will actually grow in water as well. Doesn't sound so bad does it? Well, the reason why I don't use this method is because the cutting puts out water roots. This means that when you put it in soil, the cutting has to then put out new roots to deal with the soil. This takes a while. I am not a patient person, so this method seems to take years, which means an additional couple of weeks. That translates to no new growth for a month or more.
Hopefully this information about how I root my Hoya cuttings has helped you, and given you the information that you were looking for. If not, then feel free to check out our Facebook group or page to ask more questions!