Water Lettuce (Pistia stratiodes)is a tender zone 9 tropical that grows in a similar manner to a hyacinth. The trailing roots function in much the same way as a fish food and fish haven.
The major difference is that the lettuce doesn’t flower and will grow more successfully in part shade. The velvety blue-green leaves are quite attractive. You’ll sometimes see huge specimens for sale at garden shops. Don’t pay more for these as they are simply either mother plants or those formed under high light intensity.
Your mature plants will easily reach this size in mid-summer.
Overwintering Water Lettuce
These can be overwintered easier than water hyacinths but will still stretch out in too-low light levels.
Propagation in the spring (or anytime) is by division. Simple rip the baby (that has roots) away from the mother plant and float it freely by itself.
Note that mature fish love to eat the roots of this plant and consider it a bit of a delicacy. And as the picture shows, yellowing outer or more mature leaves are not uncommon, particularly in colder water or cool nights. See below.
Sometimes in low light or cold water, the plant will start to rot. Remove the rotting sections and refloat (but do correct the water temperature or light levels if you want to see improvements.
This is more a problem indoors, while growing this plant in the shade or at the shoulder fall and spring seasons.
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