In these last weeks of the growing season, garden centres and nurseries are anxious to sell off plant stock rather than put it into winter storage. And that means bargains for gardeners! Shopping the late-season sales is one way to find good shrubs and perennials at discounted prices. Although there is limited selection, this is an opportunity to add interest to the garden and gain experience with plants we might not have initially considered.
The most important consideration is plant health, because there’s no point in purchasing a plant already succumbing to disease. None of the plants on sale now will look as fresh and pristine as they did in spring. Perennials that bloom in spring may, in fact, have spots on their leaves and look absolutely ragged after a summer in their pots. But that’s what we would expect if they had been planted in the garden, so not an important factor. However, plants with slimy, fungus-infected foliage (particularly near the plant crown) should be avoided. Perennials in pots and shrubs in larger containers should feel heavy, indicating they are still being watered and have adequate root systems. If the pots are lightweight, there may be air pockets hidden in the root balls, and possibly stunted root growth.
While perusing the perennials on sale, look carefully for double crowns in one pot. These are good candidates for immediate division, and you’ll be getting a two-for-one price bargain. Daylilies, hostas and Siberian irises frequently have enough growing points that they can be divided, and ornamental grasses crowded in their pots can also be separated into multiple plants.
Shrubs have probably been in their pots for two or three seasons by the time they turn up on sale this fall. Imagine their relief to finally get out of confining plastic and into open soil! If the roots have grown aggressively, the pot may be difficult to remove. Begin by watering the shrub to make the root ball more pliable. If the container is difficult to remove, put the pot on its side and gently compress it, giving it a quarter turn between compressions. That may be enough to dislodge the shrub, or hold the pot upside-down, and give a gentle tug on the shrub. If the shrub is still completely stuck and won’t come out, set the pot in a bucket of water to soak the root ball for several hours, and then try again.
Once perennials and shrubs are out of their pots, you may find a thick mat of fibrous roots that have run up against the container walls because they had no place to go. It’s best to tease these out a bit, using a thin stick or your fingers to gently dislodge them so they can better grasp the soil in their new holes. Shrubs with compressed roots on the perimeter of the root ball may require cutting with hand pruners to open spaces for new root growth.
Planting these late bargains is easy. Just provide a hole twice as wide as the root ball with soil that’s been amended with composted manure or leaf mould,and give the plants a good watering. Hold off using any fertilizers until next spring, when you can provide a transplant fertilizer solution to encourage quick root growth. Mulch your new plants with a four-inch (10-cm) blanket of leaves over the roots and around (but not covering) the crowns, and be glad that you made a last, late visit to the garden centre.