Container Gardening Basics

An old idea made new again, container gardening is one of the fastest growing sectors of the contemporary garden scene. Once limited to a pot or two by the door or baskets hanging from the eaves, today more than half the plants sold go into containers rather than the open soil, according to author of “The Container Expert,” D. G. Hessayon. That’s a lot of plants in a very “green” industry, a $4 billion a year industry in Ohio that grew 48 percent between 2001 and 2005.

There are many reasons for the interest in container gardening. More apartments and condos mean there are more balconies and patios to fill. People have also discovered the pleasure of creating outdoor living space and buy more plants to fill that space. Do-it-yourself, or DIY, stores have made it easy to buy supplies, and the aging baby-boomers appreciate that there is no heavy digging, little or no weeding, and no aching knees or back.

The advantages of container gardening are many. You don’t need ground, you get a continuous display, have fewer pest problems that are easier to handle, and can grow plants not suited to your soil or zone. You can grow tender plants outdoors, improve bare and uninteresting areas, and hide utility areas. Another plus is that gardeners in wheelchairs or with limited movement find container gardening easier.

Plant-filled containers can be beautiful, adding color, texture and interest to a patio, doorway, front porch, balcony, rooftop, wall, window sill, pond, path, steps or as a focal point. And if you move, you can take them with you.

Containers

Common containers are made of stone, clay, plastic, fiber, metal, fiberglass, earthenware, wood and concrete. And there’s just as much variation in the style of container. It can be a tub, trough, urn, basket, bowl or pot. Use your imagination; if it holds soil, it’s a container. Just make sure it has drainage.

When choosing a container, keep the following in mind. Some containers can be left outside over the winter while others like clay will crack and flake. If you don’t want to move them in and out with the seasons, use something like wood or concrete that you can leave outside.

Weight is a consideration if you plan to move them around, but even the heaviest of pots can be moved on a wheeled platform that also keeps the pot off the ground. It’s a good idea to raise the pots off the ground for air circulation, and that will also protect your outdoor floor surface from discoloration. Plant stands or “pot feet,” usually made of clay, work well.

Size the container to fit the location and keep plants in proportion to the container. Smaller containers dry out faster than larger ones, need more frequent fertilizing, and generally need more maintenance. To support vines or tall growing plants like tomatoes or cucumbers, you can put a trellis or topiary in the pot and plant seeds or pot plants around it.

Planting mix

Containers have limited space for roots to grow, and a plant is only as healthy as its roots, so you want to create the best conditions possible. There are many different potting mixes on the market with varying proportions of things like peat moss, perlite, vermiculite, clay and sand. It’s difficult to tell the structure, or “tilth,” of the soil unless you see and feel it. It should be a little “spongy” and slightly stick together when you squeeze it between your fingers when it’s damp.

Adding perlite and sphagnum peat moss or other water-holding substances to packaged potting soil helps keep the moisture level constant and allows more time between watering. But before you put the plants in, mix the ingredients together well, then wet with water until it is completely moistened because water runs through the dry peat moss. A hand trowel works well for mixing. Once it’s moistened, get it damp but not soggy.

Native soil is usually too heavy for pots, drains poorly, and compacts over time eliminating the air pockets necessary for healthy root growth.

Caring for container gardens

Consistent watering is a must. You may need to water daily during the hottest part of summer. Be sure to water completely so that water just begins to drip out of the drainage holes. If you water too much, you’ll wash away nutrients, not enough and your plants will wilt. If the soil is dry to the touch down an inch or two, then you need to water.

Fertilize more frequently than you would plants in the ground using a weaker solution of fertilizer. Or, use slow-release granules. Either way, follow instructions for your favorite fertilizer so you don’t burn the plants with too much or shortchange the plants with too little.

To keep planters looking their best, deadhead or remove spent flower blooms. Deadheading also encourages continued flowering during the season. Remove weeds and unsightly foliage and trim to encourage compact growth.

When a plant is done flowering or dies out, you can slip in something else consistent with the season. For instance, mix lettuce and spring bulbs. As the bulbs die back, cut the flowers (but leave the leaves if you want to use the bulbs next year) and fill with something else, leaving room for the lettuce to grow.

At the end of the growing season, clean the pots with bleach water and store where winter temperatures stay above freezing to extend the life of pots. If you planted perennials, grasses, roses, or bulbs, you can move the planter to the garage or a shed for the winter.

Deb Meager is a horticulturist widely published in local, regional and national publications and previous owner of a landscape design firm in California. Today, after changing careers and earning an EMBA from Case Western Reserve University, she uses gardening as therapy from the business world where she is principal business adviser of M3 Consulting, LLC.