Flower gardening in containers is perfect for the person who wants to have a flower garden but has limited time or space. Container gardens are convenient because they can be moved from one location to another. Container flower gardens are great for adding interest and color to patios, porches, decks, steps, walkways, pool areas, and other outdoor spaces.
Selecting A Container
The first thing you'll want to do is select a container that fits the setting it will be placed in, and one that will compliment the beauty of the plants it will contain without stealing the show.
Size matters. You don't want to put a tiny little pot on a huge back deck and, likewise, you don't want to put a gigantic pot on a small porch or balcony. Match the size of the container to the size of the space. When planting annuals in a very large pot you can reduce the amount of soil needed to fill it by fill the bottom one-fourth to one-third with plastic packaging “peanuts” or some type of false bottom. Fill in the remaining volume with potting soil.
Color and style matters. Pick a color of pot that goes well with the colors of the structure or the ornamental plants in the area. Pick a style of pot that matches the style of your home or space. If you live in a 1930's brick bungalow ultra modern pots with flashy bright colors might not be the best choice. Many nursery & garden centers offer a wide variety of containers to choose from. But just about anything you can find that holds soil and drains well is a potential container for a flower garden.
Drainage is all important. Make sure the pots you select have drain holes or are constructed of a material in which you can drill drain holes if necessary. Most clay and concrete pots provide excellent drainage and also allow air movement through the pot. That being said, clay pots are porous so they tend to dry out more rapidly than plastic and glazed ceramic pots. Needless to say, plants in clay or concrete pots usually require more frequent watering than those in nonporous containers.
Season of use. Keep in mind that because clay and concrete pots are porous, during the winter they will absorb water. Then, when there is a deep freeze, the water expands and can crack the pots. So, these types of pots should be emptied and stored in a protected place over winter to avoid cracking and chipping.
Choosing The Growing Medium
When planting annual flowers and foliage plants in containers that will be placed outdoors, use a premium grade potting "mix," not a cheap grade potting soil. If you were planting a shrub in a pot, the cheap stuff might be okay, but annual plants prefer a light mix that will hold moisture more evenly while also allowing for good drainage. If the containers will be placed in a spot that receives full, all day sun, you can use a 50/50 mixture of potting mix and potting soil. This will make the mixture a little heavier and less watering will be required. Do not use any native soil from your garden as this will result in poor drainage and aeration. Do not use straight compost, such as composted cow manure or mushroom compost, which are typically sold in bags. A double handful or two of organic compost can be added to the potting mix if desired.
Basically speaking, choose plants that will grow best where the container will be placed.
How much sun? It's important to know how many hours of direct or filtered sunlight the site receives. Is the site exposed to full, all-day sun or does it receive shade in either the morning or the afternoon. Often, pots situated on the east side of a home will receive shade in the afternoon. This allows for planting many shade-loving annuals as well as sun-loving varieties. If the site receives morning shade with afternoon sun, you'll need to select annual plants that will tolerate a lot of sun and avoid planting the shade-loving varieties. When combining a variety of plants in one container or grouping several pots in the same location, select plants that have similar growing requirements. Obviously, sun-loving and shade-loving plants are not very compatible unless the sun-lovers serve as an umbrella for the shade-lovers.
How much wind? If the site receives a lot of wind, consider using lower growing plants or, if taller plants will be used, make sure they are sturdy varieties.
Flower and foliage color. Annual plants come in an endless array of foliage and flower colors. You'll want to combine colors and textures that compliment each other or stick with a more monochromatic theme using shades of the same color. Color can be used to visually change distance perspective and to set a certain mood. Warm colors and light tints, such as red, orange, yellow and white, advance an object or area toward the observer. These colors and tints placed near the foundation of a house would make the house appear closer to the street. Cool colors and deep shades like blue, green and black recede and can be used to make the house appear farther from the street. Cool colors are restful while warm colors express action and are best used in filtered light or against a green or dark background.
A color wheel is a diagramatic way of showing relationships between colors. Colors on the right side of the wheel are warm. Colors on the left side are cool. Colors adjacent to one another are analogous (similar). Opposite colors are complementary.
Habit of growth. Trailing or cascading plants are good for hanging baskets or to cascade over the edges of containers or pots. Upright and taller plants, such as ornamental grasses, make good center pieces.
When planting annuals in containers they will often be spaced closer together than when planting in garden beds. As a rule, twice as many plants can be used in a container as in a garden bed of equal space.
If you container will be viewed from all sides, plant taller varieties towards the center and trailing varieties around the edges. If it will be placed against a wall, plant the taller varieties towards the back.
Fill the container with your soil mix to the top edge of the container. Then tamp lightly so that the soil level is an inch or so below the rim of the container. When planting annuals that were grown in plastic pots or cell pots, set plants at the
depth they were growing in the cell or pot. Then fertilize with a slow-release flower food or a water-soluble fertilizer. I prefer slow-release granular fertilizers. Then water deeply.