When a few patio containers are all you have, you want the flower arrangements in them to deliver maximum effect. Even if you have flower borders and a cutting garden "out back," containers filled with colorful flowers and a few foliage plants can soften the look of a concrete patio. Design your container gardens to harmonize with the ways you use your patio and to bring unique plants to your overall landscape, be it a great estate lawn or a tiny city yard.
Match your arrangement to its container---and the container to the type of style you want to establish. Use tall, columnar arrangements in formal and classic-shaped planters on formal patios. Create wide, casual arrangements or collections of native plants for more informal wooden or rustic container gardens in "outdoor family rooms." No matter what the planter style, your arrangement should be no higher than two times the height of the planter to allow for healthy roots and the right visual proportion.
Establish a color palette. Even if you plant a "succession of bloom"---flowers that bloom one after the other---your container garden needs a color theme. If spring starts with daffodils and summer brings bright marigolds, end autumn with bronze and gold chrysanthemums to make a monochromatic color scheme. Choose primary colors for a dynamic party scheme or pastels for a more subdued scheme on a patio that is used for more formal evenings.
Choose flowers that balance each other in form. Each container should have plants for height, body and filler. Miniature rose bushes and flowering kale each have specific, compact forms; balance and fill these structural plants with flowers of more indeterminate form such as sweet peas, nasturtiums or lobelia as filler. To finish the arrangement, use tall plants like a lily or ornamental grass to add height and linear emphasis to the composition.
Use focus plants in the composition to draw the eye to the center of the arrangement, just below the top extensions. A brilliant red begonia against a blue-green assortment puts a primary adjoining color against blues and a complementary color against green; both establish contrast. A dramatic or unexpected plant also draws attention; choose the surprising shapes of exotic cannas or bright face of a hybrid sunflower.
Establish rhythm in your flower arrangement by using different forms and textures of flower and foliage. Plant the same arrangement of plants in each of a set of patio containers, using odd numbers of the same plant in each container to avoid static compositions.