Whether it's in a window box or an antique pickle pot by the front door, a container garden can add bolder personality and color outdoors.

Whether it’s in a window box or an antique pickle pot by the front door, a container garden can add bolder personality and color outdoors.

“Container gardening is so personal,” said Nancy Baker, co-owner of Baker’s Acres in Alexandria, Ohio. “Everything goes, and that is why it is so much fun. But there are some rules that help everyone.”

Ask yourself some key questions before diving in, she advised.

“Do you like bold colors, pastels or only foliage? Will it be in the sun or the shade? Will it be seen from all sides or one side? And do you want to eat it, smell it or maybe take it inside for the winter?”

Your answers will determine your choice of plants.

First, though, you need to choose a container. Here, you can be surprising: Think old canning pots, wine crates, wheelbarrows — just about anything that can hold a fair amount of soil can become a container for a garden.

Make sure that the container has adequate drainage. “If the container you choose does not have drainage holes, the excess water will start accumulating at the bottom of the container, having nowhere to go, and eventually will rot the roots of your plants,” said Jami Baker, owner of Baker’s Village Garden Center in Powell.

Second, use a high-quality potting soil. Look for a loose, soilless mix. A soilless mix is "lightweight and allows your plant roots to grow freely,” Jami Baker said. “Other planting mixtures that are heavy or not formulated for container gardening will not provide the best growing environment for the plants.”

As for choosing plants, make sure they have similar sun requirements. A mix of shade- and sun-loving plants in one pot just won’t work. Then, use this design trick: Pick a “thriller, a filler and a spiller,” Jami Baker said. “Thrillers can be flowering or foliage plants; they provide the height and drama of the container. Fillers are plants that grow round or mounded and fill in the middle ground to make the container look full. Spillers are there to hang over the edge of the container and provide symmetry.”

Jami Baker recommends “thrillers” such as ornamental grasses, daisies, geraniums and Angelface angelonia for full-sun containers; and thrillers such as ferns, caladiums and coleuses in shade containers. Good fillers for sun containers include bidens, dianthus, lantanas, nemesias, scaevola and Supertunias. Rex begonias, Rieger begonias and nephthytis make good shade fillers. As for spillers, sun options include summer snowflakes, sweet potato vines and vincas. For shade, try Diamond Frost euphorbias, ivy and torenias.

Containers needn’t be all for show, of course. “I love planting herbs and vegetables together,” Nancy Baker said. “Salad bowl (containers) are so beautiful and can be harvested often.”

Herb combinations that take well to containers include parsley, rosemary, thyme and sage, as well as basil, chives, cilantro and tarragon. Herbs need full sun, but containers of salad greens can tolerate some shade.

Once the plants are in the container, they can be kept lush with regular food and water, Nancy Baker said.

Use a 20-20-20 fertilizer, Jami Baker said, or try compost tea or worm castings. “If you want gorgeous, healthy, blooming plants all summer long, you must fertilize,” she said.

Container plants, unlike their ground-planted kin, are completely dependent on you for all needs, especially water. “Because your plants are now self-contained and their roots cannot search for water in the ground, you must check them daily,” Jami Baker said. “Once the temperature stays in the 80s, most containers will need to be watered every day.”

Denise Trowbridge is a Columbus freelance writer who covers garden topics.