Floating pond plants

No matter how enchanting they may look, even the most captivating floating plants are prone to invasive proportions. Luckily, I don't have that problem as my two ponds actually hardly fit into pond proportions, and the second one is more of a puddle. I have envisioned a proper pond in the back yard as a thing to do sometime in the future but so far it has merely remained a vision.

Apart from the miniature water lilies, a few types of horsetail, marsh marigolds, marsh spurge and sweet flag, I also keep a few floating plants. And having in mind that floating plants are often not winter hardy and are in need of great amounts of light and warm temperature, not many survive (some say that they are not even worth all the bother of trying to overwinter them; I never thought of it like that, but keeping them in the basement tanks with low light, only a few lucky ones survive).


While rummaging through the nursery yesterday, I've noticed a new arrival of water plants from Holland. It was time to revive my floating colonies. I've got these three beauties, along with some Watermeal (Wolffia; smallest floating plants), all of them tagged as invasive in many countries:

WATER HYACINTH (Eichhornia crassipes)
known for its inflated stems (airbags) that keep it afloat; the roots are feathery (that's why Kristy and Krusty often mistake it for a birdie-toy) and a purple/white color; bears clusters of lilac flowers during warm weather; form is more compact in full sun and elongated in shady conditions; reported as a weed in 56 countries, explosive growth rate in favorable conditions: doubles its population in as little as 8-16 days ( I bought one last spring and by late fall I had over 50 new plants;
I gave many away to friends, and left about 15 to overwinter, but never bothered to inform myself on the conditions they should actually overwinter in; in low light most of them ballooned off to water hyacinth heaven, and only one survived (barely and is still in the process of getting rid of its shabby looks). From its original home in South America, it was introduced to many places where it grows profusely and out-competes native species, thus reducing natural biodiversity.;frost sensitive; hardy in Zone 9 or higher; eaten by some turtle species

FLOATING MOSS FERN (Salvinia natans)
often grown as an ornamental pond plant, but has escaped cultivation and is noxious in many regions around the globe;
grows best in open sunlight; leaves covered in small hairs; consists of three leaves, two floating ones and a third that serves as a root system; browning leaves are a sign of nutrients insufficiency; air cavities on the leaves make the plant a floating one; prevents algae by shading some areas of the pond and using nutrients in the water; tolerates occasional frost, but not prolonged periods of freezing temperatures

WATER LETTUCE (Pistia stratiotes)
not an owner of a spectacular flower; but a very interesting, ornamental pond plant; bears a floating rosette of light green, spongy leaves; also an invasive plant - several state consider it a curse and have tagged it as 'illegal'; reproduces both vegetatively and by seeds; looks better when grown in partial shade but can be grown in full sun as well; not frost resistant