I’ve been thinking a lot about containers for small trees lately. I am re-designing a garden for a client, adding more permanent color since there is a heavy reliance on annuals for color right now. While clearing out the heavily overgrown mixed shrub borders, we found a forgotten peegee hydrangea tree.
Planted improperly years ago and then slowly obscured by its faster-growing neighbors, this small tree should be a specimen tree, planted in a place of honor where it’s beautiful lines and massive summer flowers can be appreciated. But, there’s simply no place to put it. There are already two other peegees on the property so ‘finding’ a place for this forgotten one is a little more difficult than it should be.
Rather than give up on it, we decided to plant the peegee hydrangea tree in a large container and place it on one of the patios. Using small trees in containers on a terrace, patio or deck is a great way to bring your garden up close and personal. Many people use containers for annuals but don’t consider planting larger, more permanent plants, like trees and shrubs, in them.
Choosing Containers for Small Trees
Think BIG ~ We’re using a 25” square container. If in doubt, buy the next larger size. Woody plants have larger roots systems than annuals and perennials so they’ll appreciate the extra space. And the extra soil will act as an insulator once the temps really drop.
Consider the Weather ~ In cold climates, like here in Connecticut, you need to choose a container made from a weather-resistant material. Fiberglass, stone, wood and metal are popular winter-proof choices. Our container is made from a lightweight polyethylene that looks like lead. Terra cotta pots, even glazed ones, are too porous for outside use in winter. Water gets into the material, freezes and eventually the terra cotta cracks.
Improvise ~ A great way to put your stamp on your garden is to re-purpose items and make them into non-traditional containers. The possibilities are endless; just make sure you add drainage holes in the bottom.
Choosing Small Trees for Containers
Consider Your Zone ~ A good rule of thumb for choosing woody plants for use in containers in cold climates it to use a plant that is hardy to at least one zone (I prefer two) lower than your in-ground hardiness zone. My client’s garden is a zone 6B or even zone 7, so using a peegee hydrangea that is hardy to zone 3 is a good choice.
Long-term Strategy ~ Think about your long-term strategy for the plant you will using in your container. If you’re planning on growing your small tree for years in the container then choose a tree that will not outgrow the space. A small tree that matures around 15′ tall is probably a safe choice.
Another strategy is to grow young, small trees in containers for a few years until they are large enough to make an impact in the garden. This can be an especially useful strategy for expensive or slow-growing trees like conifers. Many conifers are costly and grow just inches per year. You can save some money by purchasing a smaller size, growing it in a container for several years and then planting it in your garden once it’s a bigger.
Are you growing small trees in containers? If so, I’d love to hear which ones you’re using.