|Most of us have gone through at least a spell or two of feeling undefined, maybe in the time between childhood and the teenage years or the void between the end of one baseball season and the next. I cannot be described as either driven or laid back and there does not seem to be a word for the undefined condition in between. In the garden, there are green stems and woody stems, and then there are plants with a bit of both, like tropical hibiscus.
Once a hibiscus plant is mature, its green stems are new growth that appears continuously and its brown structural stems get woodier with age. They are not technically shrubs but are also a far cry from green stemmed plants like coleus or philodendron. The former are closer to trees in their interior plumbing and so require specific rooting techniques while the latter will often root in water. Hibiscus is neither, yet both! The easiest, most effective way I know to root my favorite double apricot bloomer is a little different, too. First, I do not use true tip cuttings. Instead, cut a sturdy stem no bigger around than a pencil with 8-12 inches of brown stem. Trim off green stems and all but 3 leaves. Slice a fresh diagonal cut through the lower end of the stem at a joint (or node) and roll that end in Hormex Rooting Powder #3. Stick the cutting 3 or 4 inches deep into a small pot of damp perlite or cluster a group of 5 stems into a tall quart sized pot. I have also used rooting cubes as is often advised, but found them shallow for the tall cuttings. I have seen hibiscus rooted in sand and in bark, but I like the roots that form in a pot of perlite. They are plentiful, sturdy, and suffer little transplant shock when moved to a container or garden bed.
Some hibiscus will root in just weeks, others take much longer. If you decide to root several different varieties, give each its own container to avoid confusion later. If you have a mist system or propagation hood, use it to raise the humidity around hibiscus cuttings without overwatering them. You can leave the pots outside in humid shade, float them on a saucer of water that lets the perlite draw up what it needs, or make a cloche from a 2 liter plastic drink bottle. Cut the bottom off the bottle but leave the cap on. Set it in the pot and over the cuttings or cover a small pot with one cutting completely. As the humidity builds inside the cloche, water droplets will form on the inside. That’s your cue to take the top off to let in fresh air and prevent heat buildup.
Similar in-betweeners are butterfly bush, and chaste tree and they will also root in perlite in the same fashion as hibiscus. However, I have been able to root them from shorter cuttings taken nearer to the tip of a branch than hibiscus. The shorter, greener cuttings are much more dependent on high humidity, of course, since they are tender and wilt easily. That’s another reason to use the woodier part of the plant.
You have to remember that perlite has no nutrition in it, but is simply a support material that assists in water management around the cuttings. When rooting cuttings like hibiscus in perlite, it is important to provide a minimal amount of fertilizer and a maximum amount of rooting hormone. Rolling the stem in Hormex starts the process but you can do more. Water when the perlite looks dry on top with a solution of 2 or 3 drops of Hormex Liquid Concentrate mixed in 1 quart of water. It probably won’t take the full quart to water your hibiscus cuttings, so give a half cup or so to each of those new tomato plants. They’ll appreciate it!