(Editor's Note: This article was originally published on March 24, 2008)
Stopping the Show
In years past, when I attended the annual shows of the International Aroid Society, they had many of the display plants set up on tables for all to enjoy. That is, of course, unless the plants being shown were of the giant types. People would wander around and see the big ones, then walk to the tables, where some of the plants they would see would cause their jaws to drop. Their reaction wasn't due to large size, or incredible inflorescences; it was due to the sheer exquisite beauty of some of these smaller plants. Many of them were members of the genus Alocasia, and having once seen them, any aroid lover worth their salt will want to try growing them. I, too, tried, and I , too, lost many of them. This story is an account of my introduction to the beautiful and heartbreaking world of what I have come to call the Jewel Alocasias.
Trot to Rot
These plants are a stunning sight at professional nurseries when they are grown in bed lot quantities. Nearly each one looks perfect and the feeling you get when you see them is that you want them, all 500 or 1000 of them! The sad fact is that most of those beautiful gems are destined for oblivion, as those who purchase them at retail, not knowing how to care for them properly, will overwater them and cause them to rot away promptly. A number of these plants, such as Alocasia reginula and Alocasia rugosa, have thickened leaves, a clue that they are adapted for conditions where water scarcity is a possibility. The unfortunate truth is that often the word "tropical" is interpreted to mean "rainforest", when the two are not mutually equivalent! Even those jewels which do thrive in the rainforest, such as Alocasia reversa, shown in the picture above, right, grow in situations where the water drains very quickly through an extremely porous substrate. Loose leaf litter with small twigs, branches and shed pieces of tree bark make up the layer in which the seeds of these plants germinate and grow.
By contrast, these plants are grown commercially in peat-based mixes that remain moist all the time, and once in the possession of the plant lover, often remain wet all the time. As a result, the roots are insufficiently aerated, stressed and vulnerable to rot. It is no wonder that the destiny of so many of these plants is the compost heap. What a crying shame, too, because these plants are so desirable that those of us who have a soft spot for them will continue buying these jewels. We hope against hope to find the right combination of conditions to keep them looking as wonderful as they did the day we first saw them.
How Dry I Am!
Such a combination does exist, and it starts with keeping them much drier between waterings than we keep the other, larger, Alocasia species we grow in our gardens each summer. My first thought is that each plant I get should come with an owner's manual containing all the information about where the plant comes from and the conditions under which it grows in the wild. Alas, no such manual comes with plants, so we are left to fend for ourselves. We are smitten with the bug for these beauties, yet we lack the knowledge to keep them alive. My own work requires that I not only keep my plants alive, but that I keep them growing to blooming maturity. This fact has driven me to ferret out the knowledge and experience necessary to do that.
Drier conditions can mean watering much less, but it can also mean giving these jewels a little companionship in the pot. I've found that some ferns make great partners for these plants. The root activity of the fern plant keeps the soil mass drying out faster than it would without the fern. This gives the plant lover a little room for error in the watering department. The trick is to choose a fern that grows nicely while refraining from crowding out your jewel. For these small growers, an appropriately smaller growing Nephrolepis fern can do the trick, even in normally wet peat-based mixes.
The third way to keep your jewel from being too wet is the soil mix itself. The best mix for these plants is one which drains very fast. By "very fast", I mean that, when watered, the water should sink in within a second or two at most. If the water takes 5 seconds to drain down in a 6 inch pot, you are very likely to end up with a rotted plant! Getting your soil mix to drain this fast means you need to practically eliminate the peat in the mix. Components of a good mix are composted pine bark, washed coarse Perlite, coarse silica sand, and 10 percent or less of peat. If you are fortunate enough to have access to fallen leaves of Live Oak, rake some up and mix them in with your soil media. The leaves will fluff up the media and make it drain even faster. Just be sure you don't rake up weed seeds and soil debris along with the leaves, as that might not be such a good idea for your jewels.
A strict mineral diet
Just as important is how much water these plants receive is how much they should, or should not, be fertilized. Remember that these plants don't grow very large or very fast, so their nutrient needs are proportionally decreased. Once a month fertilization with 1/2 strength Miracle Gro solution is generally adequate for them, and in winter when growth has slowed, even less fertilizer is called for. Too much fertilizer can cause your jewel to rot away as quickly as too much water.
Nature to the rescue!
Your next trick is to use beneficial fungi, bacteria and other natural products to assist in the quest to keep your jewels happy. Some products, such as RootShield, Messenger and mycorrhizae, have been discussed in previous articles. Others will be introduced in upcoming articles. The idea is to reconstruct a beneficial soil microflora so that your jewel can be as healthy as it can be. While none of these techniques promises a guarantee of success, they can all tip the odds in your favor and enable you to enjoy your jewel for months, or even years, to come!
Picture credits: LariAnn Garner, Aroidia Research