© Janet Davis
Whether your garden is a field of dreams measured in acres, or a windowsill of dreams counted in square inches, it probably includes at least one grouping of plants in a container.
Containers
can conjure up a garden where difficult soil conditions might make the
in-ground variety impossible. A shady
corner with tree roots and poor soil?
Add a few big clay pots with hostas, ferns and luscious white
begonias. A boring expanse of
sun-drenched patio? Pot up the
heat-lovers: petunias, French
marigolds, bracteantha, osteospermum, Swan River daisies, verbena, geraniums.
Or try herbs and cherry tomatoes or other types of miniature vegetables --
perfect for containers.
In my containers, I use a lightweight non-soil mix especially formulated for planters, adding to that an equal amount of triple-mix (equal parts peat, manure, loam) to provide more mineral content. Even then, container plants will still need regular fertilizing throughout the season. One easy-care solution is to use a slow-release granular fertilizer such as Osmocote.
Although a terra-cotta urn from Tuscany looks exquisite, your petunias will be just as happy in an inexpensive plastic pot. The secret is to make sure your pots are big enough so moisture can be retained and roots don’t overheat. A minimum diameter of 30 centimeters (12 inches) is best. Window boxes should be at least 25 centimeters (10 inches) deep and high, preferably more. (Clay dries out faster than plastic, wood or ceramic, so care should be taken to water frequently in hot weather.)
Besides conventional planters, consider old wheelbarrows, claw-foot bathtubs, colorful Italian olive oil tins, watering cans, antique crocks, and wicker bicycle baskets lined with moss or landscape cloth. I’ve even designed an annual garden in the back of an old broken-down farm truck!.
If you’re adventurous, you
can try planting up your own wire hanging baskets Buy a large wire planter (available at most nurseries) 
and
a bag of unmilled sphagnum moss (not peat moss). Use dampened moss to line the bottom and a few inches up the
side, filling with potting mix to that level.
Then carefully lie plants on their side with their roots in the soil and
their heads poking out the holes, at even intervals around the circumference of
the pot. Repeat the moss/soil/plants twice more, tamping down well and
staggering the plants with the previous layer, finishing with a few plants
placed conventionally in the soil at the top and a moisture-conserving mulch of
moss.
Good plant choices for wire baskets are lobelia, fibrous begonia, browallia, fuschia, impatiens for shade; geranium, petunia, small marigolds, sunshine impatiens for sun. Trailing effects are achieved with German ivy, trailing vinca, asparagus fern, or baby’s tears. By mid-summer, the wire frames disappear under lush growth. Be warned though, moss-lined wire baskets are extremely heavy and require strong hardware and secure fastening to prevent disaster. Nicely done, they’re a big aesthetic improvement on white plastic hanging pots.
A square plywood box can be decorated with lattice, trimmed with moulding, topped with four finials, and stained forest green and voila -- a homemade Versailles planter, perfect for a rose standard with lots of cascading coral-red balcon geraniums at its base. Or consider a nicely-stained window-box filled with annuals to match.
Half whiskey barrels are often overlooked as an inexpensive alternative to costlier planters. For under $25, you have a roomy container that holds lots of plants, even small shrubs. Try a solid-colour stain to correspond to your house colour (or not – be adventurous!) and to get rid of the nasty dark look of the preservative treatment, and make sure there’s at least one large drainage hole in the bottom. Stained half barrels should last between 5-10 years.
Speaking of drainage, I fill
plastic mesh bags (the kind used for onions) or sections of nylon stocking with
a big handful of rocks, placing them on top of the drainage holes in my pots so
excess water can run out without losing good soil. These rock bags make 
a
non-messy alternative to the “broken clay shards” that English garden books
recommend. They can be easily removed,
shaken, and stored with the tools in autumn when the pots are emptied. Another alternative is small pieces of
porous landscape cloth placed over drainage holes.
Containers don’t always have to be “planted”, in the literal sense. My front porch once had a deep wooden box where an old railing had been removed. In fall, I filled it with ornamental cabbages, pots of mums, hydrangea blossoms that had turned deep-rose, and hosta leaves just starting to turn gold. In winter, there were boughs of balsam fir and pine, red-berried bittersweet, and gold-sprayed stems of snakeroot. In spring, out came the dried evergreen boughs and in went pots of daffodils, primroses and pansies, with pussy willows pushed in as companions. Only in late May was the “arrangement” removed, the top few inches of soil refreshed, and colourful annuals planted for the summer.
And don’t overlook the subtle appeal of an empty container placed artfully in the garden. Consider a handsome Chinese ginger jar in a sea of periwinkle and ferns, or an oversized glazed urn in the middle of a parterre herb garden. Simplicity, elegance – and no watering!
Adapted
from a column that appeared originally in the Toronto Sun