By Brandi McNeely, Master Gardener in Training
While shopping for plants at my local big box store recently, I came across a beautiful Monstera Thai Constellation at a reasonable price. If you’re a plant collector like me, you might think, that’s awesome! If you’re not, you might ask, what’s a Thai Constellation, and what’s the big deal?
Serious plant collectors can tell you what’s trending in the market and the crazy prices these plants sell for. Thai constellations are a natural sport of standard Monsteras, with showy variegated leaves (whereas the standard plant is solid green).
In the last few years, specimens have been selling for hundreds of dollars in specialty shops – but now they are readily available in large quantities at relatively low prices in big box stores. Why the change? To understand this, you need to understand propagation techniques.
Seed Starting
When you purchase your annual flowering plants in the spring, chances are they were started from seed at the nursery. Many plants (marigolds, zinnias, and celosia) are easy to start from seed and grow quickly, making seed starting a cost effective method of propagation for nurseries. So easy in fact, that many people start their own at home using this same method.
Division
Some plants are propagated using division. Think of your garden in the Spring when hostas begin popping up. You can use a spade to cut the plant in two, instantly doubling your plants. Some tropical plants are propagated using this method, including snake plants and calathea.
Grafting
Grafting is the horticultural technique of joining two different plants to grow together as one. When you purchase a Honeycrisp apple tree from a garden center, the tree is a Honeycrisp stem (scion) grafted onto the rootstock of another apple variety. Honeycrisp won’t grow true to seed and must be grafted in order to produce true fruit.
Cuttings
Have you ever cut a stem from a house plant and rooted it in water on a windowsill? Nurseries use this technique on a much larger scale. Using stem cuttings and growing medium, nurseries can produce large quantities of plants for sale (although this does require time to allow the cuttings to grow into small plants). Pothos are a great example of plants that are easily propagated through stem cuttings.
Tissue Culture
This brings us back to the Thai Constellation. Monsteras are easily
propagated through stem cuttings, but growing one variegated offshoot
for stem cuttings takes time. Tissue culture is a relatively new practice in the houseplant industry, where plant tissue is grown in a nutrient rich medium to produce a large volume of plants in a laboratory setting. These plants are a clone of the mother plant, ensuring consistent characteristics within large scale production. Tissue culture can produce plants on a large scale fairly quickly, driving down the cost of new, rare variations.
One plant can take years to grow into a small, steady supply of plants. Low supply and high demand results in high prices for buyers.
With advancements in propagation methods like tissue culture, the once-exclusive world of rare plants is becoming more accessible to everyday plant lovers. What was once only available to collectors willing to pay top dollar can now be found in the garden section of your local store.
Understanding how propagation influences both supply and cost helps explain market trends and reminds us that behind every “rare” plant, there’s often a bit of science making it possible for more people to enjoy its beauty.
The Peterborough & Area Master Gardeners 