All About Containers: Part One

We’ve done a complete turnaround from about 10 years ago when annuals took a back seat in many of our gardens. But now, with new varieties and the explosion in the use of container gardens, annuals and annuals mixed with tropicals and some tender perennials have become the backbone of container gardening. Even vegetables are showing up in containers for both their edible and ornamental contribution.

While most folks think primarily of terra-cotta, plastic pots, glazed pots or half-barrels as likely holders for plants, just about any “container” is a possible prospect. I’ve seen car tires, bathtubs, old wheelbarrows, shoes and boots, coffee pots, bags of potting soil, old cars, sinks, tubs and more.

If whimsy is your style,

don’t be afraid to try something different. The basics, in terms of planting and care, remain the same, though.

Container growing offers many benefits, not the least of which is that you can put a self-contained garden just about anywhere. Cement balconies at your Manhattan high-rise can become an urban garden, or splashes of color can be put on a backyard deck or patio. And, providing the containers are not too heavy, potted plants can be moved and rearranged whenever the need or mood arises.

Without a doubt, container gardens require less weeding than their in-ground counterparts, making them ideal for people who love to garden but have limited time and space. However, watering has to be watched much more closely.

As the plants in the containers mature, the pots dry out faster and faster then faster again as it gets warmer and warmer. Remember also that a container that’s darker in color will naturally retain more heat, adding to the potential water issues.

It’s tempting to add some of the water-retaining crystals and gels to the initial potting mix as these products will allow the soil to store more water, but don’t get soaked into these products. In wet years they can cause the soil to expand and ooze out of the container. And some recent research has brought the use of these products into question as much of the retained water is so tightly bound to the soil that the plants can’t use it.

The remedy to keeping the soil moist is quite natural and organic: it’s called compost. When potting up your containers, add generous amounts of compost to the mix. This organic matter will naturally absorb moisture through the season and slowly release it to the plants.

In any event, be prepared to water at least once and possibly twice a day during long, hot, dry spells. Remember as well that too much water can kill as easily as too little water.

The most common reason for too much water is a container that doesn’t have enough drainage. Excess water needs a place to go. If it can’t get out of the pot, the plants drown.

So, where would you like to put your containers and what would you like to grow?

In an area that receives full sun most of the day, you can choose from a wide selection of sun-loving flowers. In an area that receives limited sun, choose plants that tolerate less light and shady areas.

Geraniums in the shade or the wrong impatiens in the full midday sun may be the recipes for disaster, so know your plants’ needs. Remember, though, that one of the advantages of containers is that they can be moved, or most of them, anyway, and you can play some interesting tricks if you have the time to shuttle your pots around as the sun moves.

Once you know where you want to grow, choosing what to grow is the next big step. No matter what you grow, plan out each container or grouping of containers, making notes of what you would like where. For appealing groupings, include plants of different heights, colors and textures, keeping in mind that plants taller than one and a half times the height of the container may look unbalanced.

For maximum interest and to create depth, plan groupings of three to five different-sized containers. For example, one or two large pots with plants reaching about 2 or 3 feet tall, one with 18-inch plants and two with 12-inch or smaller plants. When grouped, these plants will give a three-dimensional look to your mini-garden.

One common mistake made in container gardens is choosing the wrong combination of plants. Don’t mix shade-loving plants with sun-loving plants in the same container or in the same grouping.

You can also create a garden that you can vary quickly by planting masses of one color and variety in separate containers and then grouping and re-grouping them as you like. For example, create one pot of a trailing flower, or one of a mass flower such as marigolds.

Next week, we’ll focus on choosing the right container, the right plants and some resources to check out.

You may find it helpful to get a book that is lush with pictures to give you ideas for your containers. “The Encyclopedia of Container Plants” by Rogers and Cardillo is one of the newer books with that offers more than 500 choices, including annuals, perennials, shrubs, bulbs and edibles.

And for those heading up north, container gardening is the theme of the Boston Flower & Garden Show this year, which will be held through Sunday, March 20. You can get more information at TheBostonFlowerShow.com.

Until next week, keep growing.