Where to start The word "garden" is being redefined. If it's your sanctuary and the place where, hands in dirt, you commune with nature, it's a garden. This might mean five acres in the country or a tiny urban oasis, the deck off the family room, a balcony in the sky or merely a stunning urn by the front door. Perhaps the fastest-growing area in the gardening world is that of container gardening. At a recent workshop hosted by Plant World, a garden centre in Toronto's west end, and led by senior manager Paul Zammit, a group of garden writers experienced this evolving and increasingly sophisticated art form. As a result, a spiky dracaena surrounded by a couple of geraniums will never again suffice, at least not in my containers. Here's how you can create your own traffic-stopping designs.Prep workBefore creating your masterpiece, Paul Zammit recommends the following:1. Change the potting mix every year. By the time the season is over, all nutrients in the mixture will have been used up. Recycle used potting soil in your compost or work it into existing flower beds.2. First water all plants in their cell packs or store-bought pots.3. Leave five to eight centimetres between the top of the soil and the rim of the container to allow water to slowly penetrate the root system rather than run off the surface.Like meets iike Think about where the container will be placed and select plants that require similar growing conditions (such as full sun or shade, moist or dry soil, sheltered or not), yet have different growth habits and bloom times. For high-traffic areas, consider adding fragrant foliage plants such as lavender, thyme and rosemary.Thrillers, fillers and spillers These three words, coined by garden designer Steve Silk, capture the essence of good container design. In the artful container, anything goes. Foliage only, or a mix of annuals, perennials, shrubs, herbs, summer bulbs, ornamental grasses, small evergreens, vines and tropical plants are all appropriate. It's entirely your choice.Thrillers: the tall, upright, eye-catcher placed either in the centre or off-centre in the container; plant it first. For a tropical look, try taro (Colocasia spp.), elephant's ear (Alocasia esculenta), cannas, papyrus (Cyperus papyrus), banana plants (Musa x paradisiaca ssp. sapientum) or a tall ornamental grass. Fillers: take up mid-ground space without distracting from the thriller. Begonias, lantanas, coleus, salvias, parsley, low-growing grasses and numerous other foliage and flowering plants fall into this category.Spillers: plants that flow over the edges of containers: sweet potato vines (Ipomoea batatas), ivies, trailing geraniums and petunias, Bidens ferulifolia and no doubt many more discoveries you'll make at your local garden centre.Try using roses, a small Japanese maple, an azalea standard or your favourite shrub or evergreen as the star of your container. In the fall, remove perennials, trees and shrubs from containers and plant them in the garden three to six weeks before the ground freezes. Maintenance tips Surprise factorOne of the tricks of great container design is to plant a few specimens that will strut their stuff in August and September just as everything else is starting to look a tad weary. This is where summer bulbs come into their element.Plant bulbs (at the depth recommended on packaging) before adding any other goodies. Then wait for the oohs and aahs as the flowers emerge in mid- to late summer.Five favouritesORIENTAL LILIES midsummer bloomsGLADIOLUS CALLIANTHUS tall, fragrant, white flowers with chocolate brown centres; late summer bloomsPINEAPPLE LILIES (Eucomis spp.) midsummer bloomsTHREE-LEAFED CLOVER (Oxalis regnellii has green foliage, while O. triangularis has dark purple) won't stop blooming until first frostSPIDER LILIES (Hymenocallis cvs.) with their insect-like white flowers; midsummer bloomsPaul's maintenance1. Never use topsoil or garden soil in containers. In general, all planting mixes should be porous and free-draining. Potting soil is your best bet.2. Place a piece of screening over the drainage hole(s) on the inside of pots to keep out insects such as earwigs and slugs.3. If you're a forgetful waterer, add a coir-based product such as SoilSponge to hold in moisture and extend the time between waterings. This particularly applies to containers exposed to hot, direct sunlight and those placed in windy locations.4. Because containers need frequent watering, which leaches nutrients from the root zone, regular fertilizing-preferably with an all-purpose, water-soluble product-is necessary. Follow manufacturer's directions, as more is not necessarily better. If you plant herbs and vegetables along with flowers and foliage plants, use an organic fertilizer, such as fish emulsion.5. Deadhead all flowering plants on a regular basis to promote additional blooms; pinch back foliage plants to encourage bushier, more compact growth. 6. Check containers daily-twice daily during extreme periods of heat. Water thoroughly, but only when soil feels dry to the touch two to three centimetres below the surface. It's best to water in the morning.