Cryptocoryne can be successfully grown several ways:
1) Fully emersed
2) Semi emersed
3) Fully submersed
In this post, I will detail the setup and general requirements of growing Cryptocoryne fully emergent.
Cryptocoryne, like most aroids, thrive in warm humid environments and tolerate low light levels, making them fairly easy to grow in a basic setup.
A simple, effective and low cost setup consists of:
For under $50, you can have a setup that works quite well. A typical 4′ shop light will actually be sufficient for up to 4 nursery flats, so as your collection grows, you can simply keep adding nursery flats with tall domes and expand your collection. A nursery flat can hold about 18 pots. Since you can fit about 4 of these setups under a single shop light, it gives you the ability to grow your collection to a respectable 76 pots of crypts.
Obviously, you can also use standard aquariums with glass lids to keep the humidity in. 30G or 40G breeder style aquariums work really well. For larger plants, like Lagenandra, you have no option but to keep them in larger setups since they grow quite large.
Pot up your crypts, add them to the setup and fill the container with 2-4 cm of water. You can also add about 1/4th the recommended dose of MiracleGrow or other fertilizer into the water. The use of a rooting hormone, like K-L-N Liquid Rooting Concentrate by Dyna-Gro also helps get the plant established quickly. If the plant has a lot of leaves but not enough root mass, remove the older leaves so that only 3-4 of the newer leaves remain on the plant.
In the case that you only have a small portion of the plant, don’t plant it too deep. Infact, just having it lay in a small depression and covering the pot up with Saran-Wrap will help the tiny plantlet get established.
Assuming you’re keeping the setup indoors in an insulated room, the shop light will provide enough heat as well. You want to suspend the light about 4-8″ above the dome. Raising or lowering it will affect the amount of light and heat entering the setup.
The best way to test the temperature is to measure the temperature of the water the pots are sitting in. It should be at about 75-80F. If the ambient temperature of the room is too low, the light itself might not provide sufficient heat. If that’s the case, a heater can be added to the setup. Nowadays, small indestructible heaters made for small aquariums can be bought for about $10. Having a heater in the setup also aids in getting the humidity levels up quickly.
Covering the nursery flat with a humidity dome ensures that any evaporation / transpiration stays within the confines of the setup, raising the humidity levels. Your goal is to have it between 80-90%.
..and that’s it! This is a low maintenance setup. Once a month, change the water and add fertilizer. Plants should start growing within a few weeks of being added to the setup and you should see you first few spathes in about 3 months – for the easy growing crypts anyway.