Dyed, sprayed, manipulated: do you know what's happening to your houseplants?

The pink leaves of Philodendron ‘Pink Congo’ are a chemical confection. This is not news: it's been circulating the houseplant world for nearly three years now. But a recent, rather dramatic offering from rare plant shop owner and YouTuber Kaylee Ellen pointed out that other weirdly-hued aroids are being widely sold with no warning that their appearance is temporary: "pink Micans" for instance. This has got houseplant growers pondering anew what might been done to their plants. 

This may be hard to believe in a world where everything seems in reach of Google, but we just don't know what combination of chemicals and processes have been used to induce temporary colour changes in Philodendron leaves. Avery Rowe's blogpost on Tradescantia Hub offers the most incisive summary of the story so far. Do go and read it. 

It's about time the houseplant world became more aware of the ways plants can be manipulated for our gratification, whether that's permanent or not. A few examples: nurseries treat peace lilies with the hormone gibberellic acid to induce early flowering, both as a way of bringing plants to market earlier, and to allow breeding at any time of year to produce new cultivars. Many aroids are sprayed with a slick of leaf shine that makes foliage look unnaturally glossy: once that degrades, owners cannot understand why their plant's leaves look "dull" (ie their natural texture). (The solution does NOT involve more leaf shine. This podcast episode explains why.)

Then there's mutagenesis, a technique that's been around since the 1930s: treating plants with chemicals, gamma rays, x-rays and enzymes to produce mutations that could be the next unusually variegated must-have houseplant - or a red grapefruit for that matter. And tissue culture has made possible the mass production of many houseplant species and brought tropical species such as orchids and Nepenthes - once solely the domain of the super-rich plant collector - into our homes. 

There is nothing wrong with any of these techniques as such, but it's important to know they exist. Because the more you understand about how houseplants are produced, the better able you are to buy plants with open eyes. For now, the origins of ‘Pink Congo’ and friends remain a mystery, but remember the old adage when buying plants: if it looks too good to be true, it probably is. Ask questions of sellers, and if they can't or won't answer, don't buy.

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