Most gardeners know that when it comes to container gardening, large pots are best: for the plants, for the caregiver and for visual impact. Nice ones are expensive, but even one big pot, grouped with smaller ones, can make an imposing arrangement. And you can offset the cost of that big, beautiful pot by planting it with something that will last through many seasons.
After years of laissez faire container gardening, I can suggest a few candidates.
A large pot doesn’t have to mean huge, but depth is important. My largest are 18 to 20 inches high by 15 to 16 wide. I consider the low end of “large” to be about 15 by 12. Stoneware and concrete pots are best, but terracotta works if you can keep the pot out of the rain in winter. I consider plastic a last resort as it does not age well.
I’ve been astounded at how long some plants — shrubs, mostly — can live in a container without repotting. My longest-lived container plant is a dwarf hinoki cypress. It was not young when it moved house with us 11 years ago, so my best guess is that it is now at least 16 years old. In response to limited resources it has morphed over time through self-pruning, from a dense, irregular cone shape to a more characterful open structure that sheds some green bits every year. Well, they die and turn brown. It’s up to me to rub them away with my fingers. It doesn’t take long.
Two other evergreen plants that can last a long time in a pot are Drimys or pepper bush (Tasmannia lanceolata) and boxwood. Both do well in sun or shade. Drimys produces many pretty little tufts of small cream flowers in spring that contrast nicely with the plant’s dark leaves and burgundy stems. Boxwood comes in many forms, two of them with cream variegation.
These evergreen shrubs are not showy, but they provide a sturdy backbone to a mixed group of pots and also look great in winter.
If you would prefer a flowering plant, roses are an excellent choice. You want roses with many flowers and continuous bloom. Miniature and patio roses can be grown in fairly small pots, but for a very long life in a larger pot, good bets are Floribunda varieties and oddball dwarf roses such as “The Fairy” and “Little White Pet.” All will need regular pruning and fertilizing.
Want something several feet tall? Small varieties of upright Japanese maple are perfect, and they look nice even after they drop their autumn leaves. I dug a seedling out of the garden 10 years ago and put it in a pot. It is still thriving. If you have plenty of room, a potted weeping Japanese maple looks magnificent in isolation.
Hydrangeas don’t look like much in winter, in or out of a pot, but they take well to container culture and make a dramatic summer statement. A hydrangea will slurp up lots of water. And, of course, all container plants need very regular watering and a feed with liquid fertilizer in spring and again around mid-summer. Most benefit from re-potting every few years, but they can also do remarkably well without it.
Rachel Foster lives and gardens in Eugene. She can be reached at firstname.lastname@example.org.