RE: Louisianas

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Mark,

You asked has anyone tried growing Louisiana Irises in containers and did it work without them destroying the container?  I grow Louisiana irises (Iris brevicaulis, I. fulva, I. giganticaerulea, I. hexagona, I. nelsonii & hybrids and clones), I. virginica, I. tridentata, I. versicolor, I. laevigata, & I. pseudacorus in containers. I use mainly 20” x 13” x 12 ½” deep (18 gallon) rectangular plastic tubs or containers but on occasion use smaller 14” x 12½” x 7” deep plastic tubs (10 gallon) and larger 30 gallon plastic tubs. The tubs have no drainage and I attempt to keep several inches of water over the soil surface throughout the year (spring, summer, fall, and winter).

I usually fertilize the pots once a year with a commercial 10-10-10 fertilizer; (except those containing I. tridentata, which receive no fertilizer) but on occasions I have skipped fertilizing some of the pots.  I have been asked do I encounter any salt buildup in the pots from the fertilizer.  I reside in a high-rainfall area and, I assume, that some flushing out of the tubs occurs during high -rainfall periods.  And even during long dry spells, I have not observed any problems with salt buildups in the pots.

I have also been asked do I encounter any problems with mosquitos. My answer to that is yes and no. I find that if I maintain water over the soil surface continuously and not let the soil surface dry out mosquito larvae seem to be almost nonexistent. Let the soil surface dry out and then add water to the containers and they will be full of mosquito larvae. In containers, where I maintain surface water, mosquito predators (dragonfly nymphs, water beetles, etc., etc.) evidently for the most part eliminate the mosquito larvae. And, these predators will rapidly cumulate in the tubs.  It is not unusual to observe on a single plant leaf the empty shells of two to four dragonfly nymphs that had metamorphosed into adults. The tubs will at times contain clouds of tadpoles and the serenading of frogs at night is an added bonus. Most mosquito species like temporary water pools and not permanent water bodies to breed.

In far as I can tell I do not have any problem with the irises destroying the containers. After, a number of years I sometimes have a problem with overcrowding. Also, after being out in the garden and the sun for a good number of years (4 or 5 + years), the pots start to become brittle and one does has to careful not bang or hit them too hard with some hard object. But I consider this a minor problem if one is reasonably careful.

Vic