How should I prepare iris for shipping?
The procedure for preparing iris plants for shipment from one garden to another varies according to the iris variety being shipped. There are essentially four basic categories of irises: bearded (bearded species and cultivars, arils, and arilbreds), crested (cristata, tectorum, japonica, etc.), beardless (Siberian, Japanese, Louisiana, etc.), and bulbous (Dutch, juno, reticulata, etc.).
Bearded irises are shipped dry. These irises can be moved at any time during the growing season, though they are traditionally divided about 6 weeks after bloom. It's important to get them replanted into their new garden at least 6-8 weeks before freezing weather to give them time to root in adequately before winter.
Use a spade or fork to dig up your iris clumps and wash them off well with a hose until you have removed all dirt and can easily see where the rhizomes (rzs) are attached to one another. With a sharp knife, cut through the attachments (or you can break them apart with your hands, but a sharp knife will make a smaller, cleaner wound). Inspect the rzs thoroughly. Discard any rhizomes that are soft or mushy or show any other signs of disease, any that do not have viable roots, and any that are just too tiny to bother with. Many folks also discard any rzs that have already bloomed (they will not bloom again, though they may grow additional increases). Remove any dead, spotted, or unhealthy (brown or yellow) leaves, and wipe off any insects on the remaining leaves. Cut the leaf fan back just enough to accommodate the size of your shipping box without having to bend or fold the leaves. Snip off any dead roots but leave the plump roots intact. As a preventative measure to avoid transmitting any plant pests or diseases to your trader's garden, soak the rzs in a solution of 1 part household bleach to 9 parts water for 20 minutes, then rinse in clear water. Dry the leaves and, using a permanent marker, write the name or description of the plant on a single, central leaf. Avoid writing across several leaves or on the outer leaves of a fan. As leaves dry, they tend to separate from each other, and the outer ones shrivel and die.
After you have separated, inspected, cleaned, and labeled your rzs, lay them out in a shady, dry area for a couple days to allow the cut wounds to scab over and the plants to dry thoroughly. It is extremely important to ship only completely dry plants, as any dampness (even moisture retained between the leaves) can result in mold and rot developing in transit. Once your plants are completely dry, pack them loosely into a box using a minimal amount of a breathable and absorbable packing material (excelsior, dry wood shavings, crumpled or shredded newspaper - avoid styrofoam packing materials). Punch holes in the box to allow good air circulation, and your irises are ready to travel to their new home.
Crested irises may be shipped either dry for larger species such as Iris tectorum, or with the rhizomes...