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Cultivation and propogation of Cryptocorynes


Cultivation and Propagation

In the previous installment of this series of articles on the genus Cryptocoryne we touched on an introduction to these plants. To recap:

  • Leave them alone. They hate being disturbed - more than any other plant you'll ever find.
  • Provide a stable environment. They hate change. Any rapid environmental change, be it pH, temperature, amount of light or change in general water quality, will almost certainly cause them to "melt" - a phenomenon unique to crypts where they can in a span of time ranging from a few hours to a couple of days, turn into complete and utter mush.
  • They can tolerate low light but do not require it. Many older works published before the first great boom in Cryptocoryne cultivation in the 1960's would have you believe they require low light and acid water. Nothing could be further from the truth.
Crypt. Melt

But, you shouldn't let the apparent lack of good documentation or fear of the "dreaded melt" deter you. These really are among the easiest plants to grow and certainly one of the most spectacular. Their popularity among aquatic gardners is such that if a vote were taken it is my assertion that this group would, by far, be more peoples "favorite" than any other group of plants.

To give you an idea of how easy these are to grow, let me give you an example of something that happened to me before I'd figured out how to grow these plants properly, and that time frame would be about 1974 to about 1997. My young daughter wanted an aquarium in her bedroom and my family knew better than to ask me for help or else she'd end up with something I thought was really cool, like a huge tank filled with peat fibers and a few pairs of killifish that could only be seen on alternating Tuesdays. So, behind my back they got one of those 10 gallon plastic tanks with an integrated light and filter. And platies. And a "sucker fish" and some Anacharis. This tank did not exactly rivet my attention. Frankly I barely looked at it. It seemed to prosper for a while and when it didn't I was summoned; I'd zap it with the diatom filter, remind her again about the importance of water changes, pray for the poor fish, then promptly ignore it again.

Except for this one time I snuck a Cryptocoryne pontederiifolia in there just so I could bear looking at it.

Cryptocoryne pontederiifolia
Cryptocoryne pontederiifolia

It did not do well. Despite my putting laterite in the bottom of the tank under the gravel when it was being set up, this was not a happy plant. It had at best 2 or 3 small leaves. When I realized the plant was never in the same place twice in my infrequent visits to this plastic aquatic horror (to me anyway, she loved it) and ruling out the possibility the plant was going on walk-about around the tank the kid cracked and admitted she liked moving the plants around every now and again for "something different". Oy vey.

Now, I'd love to be able to state my own efforts at growing C. pontederiifolia were going well but they were not. I was being too fussy - something I only realized later on. Mine wern't really doing much matter than hers as frankly.

Sadly, all good things come to an end, and she lost interest in the tank. The water level dropped, the filter burnt out when this happened, the whole sordid mess was unplugged and literally shoved into a corner of her bedroom. Unplugged. As in no light no heat no water movement, no nothing. It had about inch of water - maybe. It did not smell good.

Fast forward 6 months later - usually if I saw this tank in her room at this time I'd sight a black box in the corner and plan one day to annex this otherwise useful aquarium. But this day was different, I'd happened to be there at a certain time of the morning when the sun hit it for maybe half an hour and I saw a flash of green. Green? Hellooooo?

I looked more closely and found she her inadvertently grown the biggest and nicest C. pontiderifolia I'd ever seen, in person or on any website. No carbon dioxide injection, no metal halide lights, no daily chemistry set nutrient micromanagemant, no fertilizer no nothing! Are you starting to get the picture?

While on the one hand it's easy to get put off these plants by stories of the "dreaded melt" and tails of failure, you have to understand they're actually among the hardiest plants you could ever find.

My previous record of a plant surviving abuse was an Anubias. It's not a joke that if they're covered in algae you can put them in a plastic bag and throw them in a file cabinet for a couple of weeks till the algae dies off. Once, upon doing this I took the now algae free plant out and left it on a really out of the way place. It lasted 8 months there before finally dying. I had no room to put it anywhere at the time and was curious how long it would last. 8 months seemed like a long time to me.

But, that's nothing compared to what these allegedly sensitive crypts are capable of. Keep in mind "the root is everything" with these plants and of course they don't really have roots like, say, a sword plant does, they have a creeping rhizome like an Iris. On with the story: one summer I'd fed a lot of mosquito larva from a local pond and with it came an utterly awful thread algae infestation. I tore the tank down to bleach it and dumped all the crypts into a 4 gallon white plastic bucket, covered with some newspapers to stop them from drying out. There was MAYBE a half inch of water in there. You guessed it, I forgot about it. Worse, this became a makeshift trash can complete with a plastic trash can line bag. Days went by, weeks, months until finally a year and a half later in one my rare "gee, I really should clean his place up" episodes I get around to disposing of this ersatz trash can. I pull out the bag liner, and see wet newspaper at the bottom. Uh-oh.

It all comes back to me, in a flash. Prepared for what I had assumed would be just a horrific smell I hold my nose and pull up the newspaper. It doesn't smell bad. Hmmmm. In fact, what I'm looking at doesn't even look terrible. There were no leaves, to be sure, but there were a while bunch of rhizomes there. I didn't really expect anything to happen with these, thinking maybe if I floated them they may grow tiny plants like crypts do, but I decided to go for broke and just plant them all as if they were healthy crypts.

Now, get this, within a few weeks these plants had just shot up and were as big and green as they had ever been. If I had any less plants now than when I carelessly tossed them in there it was not apparent to me.

The Revived Cryptocoryne plants

Crypts not hardy? How may other aquarium plants can service 18 months in the bottom of a bucket ? Try that with a Sword plant or some Anacharis and see where that gets you.

So, we can see from this the importance of the Crypt rhizome. The leaves can come and go - get dropped at the drop of a hat, but the roots, are indeed everything. And they are, many times, the key to propogation of these plants.

It's been well understood for a very long time that if take a good length of a Crypts creeping rhizome and cut it into, say, 1" pieces and let them float in a tank they will sprout roots and leaves. You can plant them; they will grow, albeit very slowly. There seems to be a symmetry between the roots and the leaves... plants with small your roots and small leaves. Plants with a mature and large root mass will have large leaves. So, while this is not the fastest way of propagating Crypts it will work in a pinch. Just be prepared for it to take a few years till they reach the size of the parent plant.

Now, while it is possible to grow crypts from root cuttings, like so many terrestrial plants are, and we've seen the importance of the rhizome the leaves themselves are quite capable of growing new roots, and they'll do so more quickly that the roots can develop new leaves.

Now, this does not mean you can clip off a leaf and stick it in the gravel and get a new plant, that leaf will almost certainly melt. But, if you have a large well established plant - and I've done this with C. aponogetifolia, C. pontederiifolia and C. usteriana - you can cut the plant just a tad below the crown and replant it. You have to make sure you take some of the rhizome when you do this so it somewhere to grow roots from, if you don't and you cut too high you'll probably have the leaves come apart one by one in your hands and they'll just die on you. But if you do this correctly the plant will grow roots almost immediately. It may take a few weeks or months to put out new leaves but I have yet to see one go into melt when I've done this. Presumably because there is so much leaf material to photosynthesize food the plant does really well from here on out.

But what becomes of the stump you left behind when you cut all it's leaves off? Ah, it grows new leaves. Now, it doesn't just start growing a new plant, as big as the old one from the base, no, it grows a lot of small plants, usually 4-6 in the (relatively) few times I've tired this. They don't seem to be particularly fast growing and in this case the leaves seem to be more important than the root - a paradox it would seem.

Cryptocoryne pontederiifolia
Cryptocoryne pontederiifolia. The plant was severed from the root
and potted on it's own; this is the plant in the background.
The daughter plants growing from the old rootstock are
in the forground
An annoying C. lucens is in the way, out of focus. This is a 20 gallon tall tank.

The method is propogation is not some whim I cooked up and I make absolutely no claims to originating it, I heard about it from an importer in the Philippines although I suspect it goes back further than that - I've just never seen it mentioned before. But, if you were to buy a few boxes of crypts that's how they'd come, no roots at all; typically they're floated for a couple of weeks until they develop roots, and then sold.

Cryptocoryne usteriana
Cryptocoryne usteriana.Wild import from Morco in the Philippines. He cuts the plant off from the rootstock and then just ships them; they arrive "bare root". Up to a dozen new plants then grow back from the rootstock still buried in the ground. You float the plant for a week and new roots develop; and then you can plant it.

Copyright 2022 Richard J. Sexton
Aquatic Aroids