By Paul James
Rains this week have put on damper on gardening, but that doesn’t mean you can’t plant. After all, putting all kinds of things in containers is something you can do regardless of weather – in the garage, on a covered patio, even between downpours. And while obvious choices include flowers and tropicals, there’s a group of plants that’s often overlooked when it comes to container planting.
And that would be trees and shrubs, which can be used in a number of effective and dramatic ways, from formal to funky. For example, to flank the entrance to your home, especially if the surrounding surface is concrete; to use in a spot where nothing will grow due to poor soil or drainage issues; to add a special decorative touch to a garden bed; and to draw attention to a specimen tree or shrub.
Practically any and trees and shrubs are contenders for containers, but here are three things to keep in mind before you make your selections. First, realize that you’ll need to fertilize the tree or shrub more frequently than if it were planted in the ground, because fertilizer leaches more rapidly out of a container. Second, be prepared to top-dress the container with a two- or three-inch layer of fresh potting mix every year. And finally, plan on repotting every three to five years, ideally in mid to late February. The process is straightforward: use a sharp knife to loosen the soil and roots from around the inside of the pot. Gently remove the plant (tipping the container on its side if necessary). Discard (or better yet, compost) the old potting mix. Repot using fresh potting mix.
If you want to return the plant to its original container, prune about a third of its roots. If you want to move the plant into a larger container, simply trim the ends of the roots to encourage new growth before potting up.
One more thing: Try to balance the size of the plant and the pot. A six-foot tree in a 12-inch pot will look weird, and the plant won’t grow well.
I’ve grown dozens upon dozens of trees and shrubs in pots over the years, but among those I like best are Japanese maples, Japanese snowbells, crape myrtles, dogwoods, evergreen conifers of all kinds, and hydrangeas. Of course, there are dozens more trees and shrubs to choose from, and I encourage you to try anything that strikes your fancy. And realize that once you start planting trees and shrubs in containers, you’re likely to discover a whole new world of gardening.