There was a time when you would need a bunch of really strong friends to help move a huge container, but technology has made things a lot easier. Newer lightweight foam and durable polymers are used to create extra-large containers designed to look like terra cotta. This has opened the door for many gardeners to create bigger, bolder displays. We chose a molded-foam container that is 4' wide to make a bold statement on our patio. This extra size will allow us to use some plant material such as flowering shrubs and larger conifers that wouldn't fit in a smaller container.
To get started, first make sure there is good drainage. If the pot doesn't already have them, you'll need to drill drainage holes spaced equally from the center of the container. Use metal mesh to cover the drainage holes to hold back the soil from leaking out.
For the soil mix, I suggest using a commercial nursery or container soil mix. Fill the pot 6" from the top.
Start by planting the tallest plants in the center and moving out from side to side from the tallest to the shortest plants.
For our center plant we chose a tall skyrocket juniper. The blue-green foliage will provide year-round beauty. Its strong structure also provides a wonderful formal statement on which to build the container arrangement. Here's an important reminder: make sure not to plant the juniper below the original soil level of the nursery pot.
Next add some color. We used fairy roses with pink flowers to provide a strong punch of color from early spring to fall. Plant these all around the juniper.
With larger containers it's important to add texture. The New Zealand flaxes we added will do the job, and their spikes are a nice addition. You want the container to look balanced, so make sure you plant them on each side.
For additional texture and color we planted yellow globe junipers. They look kind of hairy, and since we have so much space in the container, it's important to pick plants that will stand out. The yellowish-green foliage of the globe juniper complements the other colors and contrasts well with the pink in the roses.
And for a final touch we added blue rug junipers to the right of the yellow junipers. They will cascade over the sides of the container and provide year-round color contrast with the yellow juniper.
Finally we added a time-release fertilizer around each plant and mulched between the plants with a hardwood mulch.
So here are the things to remember when planting a large container:
- Provide drainage for the container and cover drainage holes with screen to hold soil in.
- Use a soil mix designed for containers, to provide good drainage and moisture retention.
- Choose plants that complement in texture and color, going up down and all around.
- Fertilize with a complete fertilizer.
