One of the most frequently asked questions we get is whether or not iris
can be successfully grown in containers. Any iris can be grown in a
container temporarily. Since most perennial gardens are not renovated
until late fall or early spring, planting newly purchased rhizomes in
simple plastic pots is an excellent way to allow your acquisitions to
start rooting in preparation for transplanting. MDB, SDB or MTB irises
can be temporarily planted in 4"-5" pots although 1 gallon pots are
recommended. IB, BB and TB irises can temporarily be planted in 1 gallon
pots, although 2 or 3 gallon pots would be better. If you are holding
Beardless Iris in pots for later transplanting, Siberian and Pacific
Coast Native irises should be planted at least 1 gallon; 2 gallon pots
would be better for Japanese, Louisiana or Spuria Irises. The general
rule of thumb is to keep in mind that the longer the plant will need to
live in a pot, the larger the pot needs to be.
When considering long term container culture, of the Bearded Irises we
like to limit our recommendations to the median types (SDB, MTB, BB,
IB). Miniature Dwarf Bearded (MDB) irises tend to not offer much in the
way of foliage, and can be too easily crowded out when planted in a
mixed planter. While the flowers are an essential part of the
presentation, the sword-like foliage of iris adds a striking contrast to
mixed container gardens. The lighter-weight foliage of SDB's and MTBs
make these types excellent for small mixed planters. The heavier foliage
of BBs and IBs will lend substance to larger mixed containers.
When considering long term container culture for Beardless Irises,
Japanese and Louisiana are the best suited. Siberian iris do well also,
but since their root structure can be quite dense, the maintenance
required will be higher. If you choose to grow Louisiana iris in
containers, be advised that they must stay moist at all times. The
easiest way to do this is to set the pot in a tray that will hold water,
and then keep the tray filled with water. Japanese iris are probably the
easiest Beardless iris to grow in a container.
Note: Iris are heavy feeders, so don't forget to add a good 5-10-10 or
10-20-20 fertilizer to the pot two or three times a year!