This year I developed a ‘thing’ about air plants. It started with buying just one, meaning to attach it to an object to make a present for someone. Almost in the same way that you would stick on a sequin I guess. But of course, as soon as I actually touched it, I remembered that it was a life-form, not a bit of plastic.
So I got a couple more, and started trying to understand how they work. The easiest to observe in a short period of time (air plants live in slow time) is Tillandsia caput-medusae.
Tillandsia, named for Mr Tillandz (1640-1693) a Finnish botanist, by Linnaeus (many thanks Wikipedia) is a big genus, part of the Bromeliaceae family. They tend to originate in South and Central America, though not exclusively. Tillandsia caput-medusae invites comparison between the structure of the plant and the snake-hair of the Medusa’s head (lit. caput medusae). There are 4 specimens above, and you can see how they do (or don’t) fit the picture below. They tend to coil slightly more tightly when they are in need of watering.
Tillandsias are popularly known as air plants, which probably leads to the death of thousands in the home. The ‘air’ in air plant refers to their epiphytic nature: they live in air (on other plants, rocks, trees, phone wires, etc) rather than in soil. They don’t live on air, particularly not in centrally-heated domestic homes.
In the absence of roots, tillandsias absorb both water and nutrients through silvery trichomes on the surface of their leaves – seen in the above photo. These trichomes have three functions for the plant: their silvery colour reflects bright sunlight, they allow water to be absorbed from rain and atmospheric humidity, and they protect that water from evaporating once it has been captured. If you have an airplant, it is important that you bear this in mind when you are caring for it. It needs access to water regularly or it will die of dehydration, but it is in danger of rotting if the water is allowed to gather and rest in the spaces between the leaves.
Watering should therefore be done once or twice a week, depending on the conditions the plant is living it (sunny window in warm conditions – twice; no sun, chillier conditions – once). All it needs is to be run under the tap, or popped in a bowl of water for a bit. If your plant gets dehydrated leave it in a bowl of water overnight. As with all houseplants, it really helps to understand how your plant feels when it is healthy. You won’t damage it if you handle it regularly, as long as you are careful. A healthy plant will feel slightly cooler than ambient, and it will feel gently springy rather than crispy in your hand. This will vary between species of tillandsia, but for caput-medusae firm and gently springy is good.
Then drain it (on a teatowel or whatever comes to hand) for an hour or two, upside down so that the water can drain out from between the leaves. If your plant is growing upside down anyway, so much the better.
One of my caput-medusae caught me out by flowering long before I had expected it to. I am told that one way to encourage them to flower is to feed (weekly-weakly) with very dilute plant food, I use about 1/10th the recommended rate for my plants. As you can see on the photo above the flower-stem comes from the centre of the plant in this case, and starts off green with pink tinges.
The inflorescence takes quite a while to develop, but once the purple flowers appear they last a very short time, slightly less than a day per flower with this plant. That said, the flowers are produced one at a time, so the display is quite long-lasting, and immensely attractive.
And once the flowers fade, the plant should move on to producing an offset (a clone plant that remains attached to the parent until it is of sufficient size to live independently). You can just see the offset nestling in an older leaf at the bottom of the plant here.
Over time, the plants will produce a mass of many plants. Pictures of plants in the wild here, and here.
Update photos of offset: 8-10-16. (The wire is not for the purpose of restraint but suspension).