Spotlight on Calathea "White Fusion"

Introduction

Calathea (Family: Marantaceae, Genus: Calathea) are among the most beautiful of the "foliage" houseplants, but they are notorious troublemakers for many owners. The biggest single reason for these problems are improper watering (of which I am definitely guilty, at times) and insufficient humidity (not such a problem during the summer in North Carolina, but definitely going to be a new challenge in the winter). While these problems are true of all Calathea (which will one day get their own posts), they are double trouble for the Calathea "White Fusion" hybrid. Details are scarce on the source plants for this sterile hybrid of Calathea, but it is a unique leafed plant struck throughout with beautiful white, cream, light green, and dark green variegation on long, narrow leaves with fuchsia undersides. Like all Calathea, they have a hydrodynamic petiole that allows them to move in response to light and water - generally this means that they fold upwards and night and fan out during the day.

Joys

The White Fusion is a beautiful plant, as you can see from the pictures. Unlike some plants that have "juvenile" and "mature" leaf forms, the leaves on this plant have their full, beautiful coloration from the very beginning and will grow larger and larger as the plant grows. It starts off very small, easily fitting into a 4" pot and roots deeply and quickly, allowing you to up-pot quickly if you like. The more room you give it, the larger it will become, but you can maintain a perfectly happy smaller plant if that works better for you. It is a very rapid grower, often putting out multiple leaves per week from different growth points. Due to the way that it offsets through an underground rhizome, the clump will continue to grow larger and larger, seemingly stimulated by root contact with the walls of the pot. Most people say to keep these plants in a plastic pot because of how thirsty they are, but mine is doing dramatically better in a terra cotta pot than it was in plastic, but your mileage may vary.

Challenges

The challenge with this species has everything to do with the white variegation on the paper-thin leaves. White areas on plants (all plants) are devoid of chlorophyll and, therefore, produce no energy on their own. This leaves them very susceptible to dying from what would be considered minor inconveniences elsewhere on the plant, including slight changes in humidity, drops of water on the leaves, too much light, or no discernible reason at all. The white parts on most of the leaves will, sooner or later, die away, leaving a crispy-edged leaf with perfectly normal and healthy green areas and browning where the white used to be. 

Those crispy edges are a source of worry on any other plant, but just another day for Calathea "White Fusion."

General Care

Pro-Mix seems to be the best potting mix for this plant, with a great blend of fluffy coir, evenly sized perlite, and a solid nutrient base. It can be difficult to find in some places, so any general purpose potting mix with a good amount of perlite will work. What you do not want is a mix that cakes down on the roots, which will cause them to rot. Calathea may naturally experience unending rainfall, but the soil conditions in the rainforest are fast-draining and nutrient poor, so we should try to replicate that in our homes. They do not necessarily want an "aroid" mix, which would include more orchid bark and even more perlite, nor would they do well in a succulent mix. 

Water when the top of the soil is dry. I am a fan of judging by touching the top of the soil and then lifting the pot. Is it heavy? Wait another couple of days. Is it nice and light? Definitely time to water. Once you get a feel for it, it's the simplest way to figure out when to water. You want more of a mid-weight to this one since they do not like to completely dry out. Other Calathea (musaica, lancifolia, makoyana, etc.) are much more tolerant of drought and can be let to dry completely, but most are going to appreciate more moisture. 

General "houseplant light" will work fine - bright, indirect light is good. The will lose some of the variegation if there is not enough light, but may get sunburn with too much light. No direct afternoon sun for sure though. It will grow very quickly in proper lighting conditions, so if you haven't seen a new leaf in a couple of weeks, check the roots and then maybe move it or give it a grow light.

You need a humidifier. Not a tray of water, not a cluster of plants. A humidifier, on all day long. Most places, you can probably turn it off or down at night. A hygrometer will help you figure that out.

Conclusion

With such a temperamental personality, why would anybody bring this fickle beauty into their home? Of course, when it looks good, it looks fantastic, but the biggest reason is that they grow so quickly under good conditions that the dying leaves can be clipped off or ignored and you still get net growth of the plant. Additionally, as with most Calathea sp., they have an underground rhizome that stores water, nutrients, and sugars that enable them to die back completely to the soil and regrow when conditions are better. This is an excellent adaptation for home growers during the winter, when it proves exceptionally difficult to keep many plants alive. Most people would give the plant up for dead at this point, but wait! Water the pot very infrequently and only when it is quite dry and wait until the spring comes around to step up the watering frequency and see if something sprouts, it may surprise you! You can always dig in a little to find the rhizome and if it is still alive, you have a great chance. Why these plants would have retained this ability, given their natural habitat in South and Central American rainforests, is unclear, but presumably a recent ancestor faced environments that were more irregular in rainfall and humidity. It makes Calathea "White Fusion" an extremely forgiving plant in many regards - even if you damage the existing foliage, the new growth will quickly respond to any improvement in conditions. It really will let you do some trial and error until you figure it out. The easiest way to keep it happy would be to buy a glass cloche for it to live in, or a large terrarium. But these are not necessarily the best for most people, so open-air conditions are important to find. High humidity is very important, so people in the South are likely to have more success with less maintenance with this plant, although anybody can create the proper conditions with a little more work. It's a beautiful plant to have, but maybe only one (or two). Thanks for reading!

Lots of great new growth!