Whether it's a question of space or interest, container gardens are everywhere. Maybe it's because they are so much fun to create and offer immediate gratification.
There are no "rules" for designing a container garden, except to give the plants what they need to thrive. However, there are certain design principles that can be scaled to container size and make creating effective container gardens an art.
Think of them as Rules of Thumb, not "rules" per se.
Balance and Contrast
The first things to consider are balance and contrast.
- Plants should be sized to the pot and pots should be sized to the site. Small plants will be lost in a large pot, just as small pots will be lost on a large deck.
- Plants shouldn’t be more than twice the height of the pot or 1 ½ times as wide.
- Simple plants show off an ornate pot, flamboyant plants are showcased by simple pots.
- Have at least 1 tall plant, 1 filler and one trailing plant in a pot, or simply one plant per pot.
Sometimes it's nice to have just one type of plant per container. Bold plants, like zonal geraniums (Pelargonium), look very nice on their own. You can always group several pots together.
Color is of primary importance.
- Suit your choice of colors to your site.
- For drama and impact, go for contrast (colors opposite one another on the color wheel).
- For harmony and tranquility stay with one color in different shades, like lavender, lilac, and purple.
- To show off the color of the container, don’t hide it with trailing plants.
- Use foliage for color
Bones & Focal Points
Container gardens are the perfect place to experiment and have fun. Use whatever plants you like.
Mix in perennials, trees, shrubs, houseplants, vegetables, and herbs. Use whatever strikes your fancy as a container. If it doesn’t have drainage holes, plant in plastic pots and place the pots inside the container. Include garden art in your containers or groupings. And place pots anywhere there’s an open space: on the deck; the front steps; in holes in the flower border; or create borders and screens with potted evergreens or bamboo. If you don’t like what you’ve created, take it apart and start again.
- Use foliage as the bones of your container garden. Find interest in the color, texture, and size of the leaves. For instance, coleus for color, grasses for spiky airiness and Hostas for bold, textured leaves.
- You can create a focal point within a mixed container with height, bold leaves or striking color. For instance, phormium for height, hibiscus for striking color, elephant ear (Alocasia esculenta) or cannas for drama.
- Create a focal point with a grouping of containers, each with one large plant, like a pot of black bamboo, a bugmansia and some Gartenmeister Fuchsias.
Tall Focal Points or Solo Performers
Container gardens can look one-dimensional without a tall plant or two to provide some height. Don’t feel restricted to only the spiky Dracena on sale with the annuals at the plant nursery. Here’s a list of tall plants that would be perfectly at home growing in a pot. Your choice of plants is only limited by the size of your pot. Here are some tall plants to consider:
- Amaranth (Amaranthus)
- American arborvitae (Thuja occidentalis)
- Big bluestem (Andropogon gerardii)
- Cabbage tree (Cordyline indivisa)
- Common boxwood (Buxus sempervirens)
- Dwarf Alberta spruce (Picea glauca)
- Elephant Ear (Alocasia esculenta)
- False cypress (Chamaecyparis obtusa)
- Feather reed grass (Calamagrostis x acutiflora)
- Fountain grass (Pennisetum setaceum 'Rubrum')
- Monterey cypress (Cupressus macrocarpa)
- New Zealand flax (Phormium tenax)
- Palm Lily (Cordyline)
- Princess Flower (Tibouchina urvilleana)
- Sweet Bay (Laurus nobilis)
- Tufted fescue (Festuca amethystina)
- Other Tall Focal Points
Good garden design relies heavily on the choice of filler plants. Filler isn’t a very respectful term, but filler plants can make or break your garden. They need to perform well over a long period of time and complement each other while highlighting the focal points in your container garden. Great foliage is often the key to a great filler plant. Colorful or textured foliage provides interest all season. Here are some to consider:
- Abutilon (Flowering maple)
- Agastache foeniculum (Anise Hyssop)
- Celosia (plume flower)
- Coleus (Solenostemon scutellarioides)
- Cuphea (Firecracker Plant)
- Eucalyptus (Eucalyptus cinerea)
- Euphorbia marginata (Snow-on-the-mountain)
- Iresine (Blood-leaf)
- Lantana (Lantana camara)
- Ornamental Cabbage and Kale
- Perilla frutescens (Shiso)
- Salpiglossis sinuata (Painted Tongue)
- Senecio cineraria (Dusty Miller)
- Strobilanthes dyeranus (Persian shield)
- Swiss Chard
- Other Filler Plants
Even the nicest container garden is softened and somehow made more cohesive if there are plants trailing down its sides. Luckily plant breeders have been developing better and better choices of trailing plants. A great trailer for a pot is one with a long season of bloom, that doesn’t need immediate deadheading. Many annuals do better in either cool or warm weather and can be swapped out when the weather changes. Here are some trailing plants to consider:
- Alternanthera dentata
- Asarina (Chickabiddy)
- Brachycome (Swan River Daisy)
- Calibrachoa (Million bells)
- Cobea (Cup and Saucer Vine)
- Creeping Zinnia (Sanvitalia)
- Eccremocarpus (Glory Flower)
- Helichrysum petiolare (Licorice plant)
- Iberis (Annual Candytuft)
- Ipomea batatas (Sweet Potato Vine)
- Ivy geranium (Perlargonium peltatum)
- Lotus berthelotii (Parrot's beak)
- Plectranthus argentatus (Silver plectranthus)
- Scaevola (Fan Flower)
- Thunbergia alata (Black-eyed Susan vine)
- Wave Petunias
- Zinnia angustifolia (Narrowleaf Zinnia)