Preparing for the actual Perennial Planting

How to plant your perennials has a lot to do with how you acquired them, whether by mail-order, from the local nursery, or as a division from a fellow gardener.
If you purchased your plants mail-order as pots or bare roots, here’s what to do when they’re delivered to your home:

1. Unpack immediately, and inspect the plants. As with potted ones, you want to be on the lookout for obvious problems of pests or rot. And you want to see crisp roots. You shouldn’t see any green stem or leaf growth yet, or at least not much.
2. Hold the plants in a cool, dark place until you’re ready to plant them — perhaps for a few days or a week at the most. The refrigerator is also fine. Mist them lightly if they seem dry. If you can’t plant right away, pot them, water well, and care for them in a sheltered location.
3. On planting day, rehydrate the roots by soaking them in a bucket of tepid water for a few hours.

Here’s how to handle plant divisions (see “Dividing perennials” for info on doing the separation):

• Keep plant divisions moist. Don’t let them dry out! This idea is especially important if you’re not prepared to plant the divisions in your garden right away. Place them in a plastic bag or box and sprinkle on some water or temporarily pot them; water well.
  
• Clean them up. Clip off or tug out weeds and limp, yellowing, or damaged foliage. Cut off flowering stalks (don’t worry, they’ll generate new ones soon enough). Right now, you just want to the divisions to devote their energy to establishing their roots in your yard.
• Plant in a prepared area and keep an eye on them. Don’t just toss divisions on the ground and hope for the best, even if your friend characterized them as tough guys. They need time, water, and weeding to get their legs under them.