Using Evergreens in Containers
Container gardening has been wildly popular for the past several years. Gardening in different colored and shaped pots can be an easy way to incorporate colors and textures to the landscape. A tall central piece is usually needed to balance out the design of container gardens. Tall annuals, perennials, and shrubs can all fill this niche. The advantage of using shrubs is that you can plant them in the landscape when the container garden is redesigned. In this article, we will identify some good shrubs for containers and point out their uses in the landscape.
Shade Loving Evergreens for Containers
Rhododendron – Rhododendrons are generally wide plants in nursery pots so a fairly large container will be needed. In pots as well as the landscape, rhododendron adds bold texture and beautiful clusters of large vividly colored flowers in May.
Azalea – Azaleas, particularly encore azaleas, can add a ton of color to containers throughout the season. Encore azaleas bloom in spring, summer, and fall unlike the traditional azaleas which only bloom in the spring season.
Daphne – Daphne is without a doubt my favorite shrub because of its wonderful fragrance during its blooming season (January, February, and March). The good thing about growing daphne in a container is that drainage is typically good in pots, so it is hard to over water. Daphne does not tolerate wet soils so it can be easier to care for daphne in a pot. Try to combine daphne with other plants that do not require much water and use less potting soil combined with more planting mix in containers.
Camellia – The odd blooming seasons of camellias have made them popular plants in southern gardens for many years. It can be hard to find a plant that flowers in the late fall and winter months but camellias fill this gap. In containers they add nice vertical interest as well as their abundant flowers.
Sky Pencil Holly – ‘Sky Pencil’ holly does not have a lot of the bells and whistles associated with it as some of the other plants we have discussed, but it does a wonderful job as an upright evergreen in a pot. ‘Sky Pencil’ is also extremely narrow, leaving ample room for other additions to container gardens.
Aucuba – Foliage color and texture are what make aucuba an impact plant in containers and gardens. The large leaves are often variegated with splotches of yellow and quite eye catching in dark areas of the landscape.
Sun Loving Evergreens for Containers
Dwarf Alberta Spruce – Dwarf Alberta spruce is prized in containers for its formal, dense, conical shape. They usually do not take up much space due to their narrow form.
Sky Pencil Holly – Same as above
Nandina – Nandina provides a colorful punch to container gardens. The foliage transitions from bright green in the spring and summer to vivid crimson red in the fall and winter months.
Yucca – Yuccas can add a topical or southwest feel to containers depending on what they are combined with. Their spiky colorful leaves add an interesting texture to pots.
Windmill Palm – Speaking of topical plants, windmill palm can be a really neat addition to containers or landscapes. These winter hardy palms go great by patios or pools. In the landscape, they can attain heights of over ten feet.
Carolina Sapphire Cypress – ‘Carolina Sapphire’ is another upright columnar shaped evergreen that does not take up too much space in pots. The attraction here is the nice blue color of the foliage.
Curly Leaf Privet – This privet has a nice dense tight form that lends itself well to containers. Much like the ‘Sky Pencil’ holly, there is not much to this plant aside from its curled foliage.
Planting and Care of Your Evergreen Container
Evergreens will last anywhere from one to three years in a container and will then need to be planted in the ground, as they become root bound. As with planting any other shrub, the first thing that should be done is making sure that your plant is being placed in a spot where it will succeed. Make sure sun plants are going to get some sun, and shade plants are going to be sheltered from the sun. Carefully remove the shrub from the container and remove any excess potting soil. The potting soil from the pot is usually not the ideal amendment to use in our clay soils here inWakeCounty. Dig a hole that is three times the width of the rootball but not quite as deep as the rootball is tall. Amend the native soil with planting mix. I like to use about ½ to 2/3 planting mix to native soil. This allows for good drainage and aeration for the root system. Place your shrub in the ground and backfill around the rootball. I see many people make the mistake of planting too deep. Make sure that an inch or two of the rootball is above grade. Use some of the remaining soil and planting mix to cover up the remainder of the rootball, leaving the top of the rootball exposed. Water your plant in thoroughly and follow a regular watering schedule and you should be set.
– One gallon evergreen plants should be in at least a 14” container.
– Three gallon evergreen plants should be in at least a 18” container.
– Fill bottom half of container with planting mix.
– Fill top half of container with potting soil.
– Fertilize with Osmocote (a slow release fertilizer) every four months.
Watering Your Evergreen Container
One of the biggest problems with evergreen container plantings is that either the evergreen gets over watered or the plants surrounding the evergreen get under watered. To avoid this problem, you simply need to follow a couple of guidelines. For the evergreen part of your container, water generously until water begins to flow out of the bottom of the container; you should do this once a week as these are generally larger plants with a more vigorous root system, therefore they need more water. For the flowering or foliage plants around your evergreen plant, lightly water every two to three days during warm weather. Once it gets cold, you will only need to water once a week. For a complete list of plants that are great options for fall containers, see our FALL ALTERNATIVES ARTICLE.
– It is also important to make sure you use a container with really good drainage.
– Make sure the container is made of a material that won’t crack if it is wet during winter weather (freezing).
– Do not use saucers in winter as you do not want your plants setting in water.
– Make sure containers are light enough to transport or are on plant caddies with wheels. You will appreciate this during inclement weather (so will your back!).