The problem with the 'sweetheart plant', Hoya kerrii

Millions of single-leaf Hoya kerrii - often marketed as ‘sweetheart’ plant’ - fly out of florists, shops and garden centres, especially in the run-up to Valentine’s Day. But will these individual heart-shaped leaves ever amount to a plant?

The answer, frustratingly, is maybe. Unlike certain succulents such as Echeverias, Hoyas will not grow a new plant from a single leaf. To make a Hoya kerrii cutting grow more leaves, some portion of stem must be attached to the leaf stalk, aka the petiole.

I have heard from several people who have successfully grown a whole plant this way, although it can take several years for a shoot to grow from the base of the cutting and get established. It all depends on whether a sliver of stem was cut away with the leaf when it was taken. If this happens, the tissue in that stem will eventually sprout. In order for a piece of a plant to produce roots and shoots, it needs to contain what is called meristematic material, aka undifferentiated cells. These cells have the capacity to turn into roots or shoots, depending on what the plant needs - this is known as totipotency. Some plants can be produced from leaf cuttings, because they have this material in the leaves - other plants can only be produced vegetatively from stem cuttings, because that’s where the meristematic material lies.

In summary: it is a lot quicker to buy a Hoya kerrii stem cutting or a whole plant, if that’s your aim. Read more about taking care of Hoyas in this article I wrote for Gardens Illustrated. If you want to get geeky, check out On The Ledge episode 98 where I talk to horticulturist Leslie Halleck about the science of plant propagation.

This blogpost was adapted from The Plant Ledger, my twice monthly email newsletter about the houseplant scene. Subscribe here and get my free in-depth guide to fungus gnats.