No garden is complete without at least a few containers for seasonal color. I always specify locations for planters when I create a new landscape design, with the intention of keeping them filled in every season. Although many gardeners keep their containers filled with annuals in summer and cut greenery in winter, there is another option. Planting a dwarf evergreen that can remain in its pot for several seasons will provide structure and texture every month of the year.
When choosing an evergreen shrub or tree for an outdoor planter, look for cultivars that are hardy one zone colder than your area. In other words, if you live in Zone 5, your selection should be hardy to Zone 4 or below. Growing conditions for plants in a container are harsher than they are for plants in the ground, so additional resilience is necessary.
Your next decisions are aesthetic: Are you looking for something tall and formal, low and spreading, or something entirely different? Here are a few options to get your search started.
If you need a plant that is easy to manage and has a classic look, a boxwood (Buxus spp. and cvs., Zones 4–9) is a perfect choice. My two favorites are ‘Green Velvet’, which has a globe form, and ‘Green Mountain’ (pictured), which has a loosely pyramidal form. Having used these almost exclusively for over 20 years, I can attest to their hardiness and resilience in containers. Among the most commonly used evergreens for containers, boxwoods lend themselves to being pruned to almost any shape or size, or they can be left in their natural form. A coat of anti-desiccant spray applied in early winter will help reduce foliar damage and dehydration.
If you’d like to to add some cool silvery-blue color to your containers, dwarf
Read more on finegardening.com