You can dote on a fussy specimen with container planting. Practically speaking, you can move plants indoors in cold weather. But there is a lot to know to keep your thumb green with this type of gardening!
The Ground Rules Explained
Container planting lets you decorate your open patio, front porch, poolside concrete expanses and window boxes. You can move these containers around as weather dictates; or you can bury them in the ground, put them in a greenhouse or even gift them. You can get creative with sources of containers--everything from small buckets to old rowboats. You can go formal with manicured topiary or casual with a dense mix of annuals and grasses in a whiskey barrel half. Lifting a container off the ground with a stand allows for eye level viewing for more shallow pots. Water flows more freely out if over watering could be an issue. Smaller pots can be hung from the ceiling or attached to a wall as a half-basket. This way you keep them out from underfoot.
Handy and eye-catching!
There are porous and non-porous containers. Porous containers like terra cotta and wood will dry faster and cool by evaporation and allow roots to breath. Mulch is useful on top of the soil to slow evaporation on hot days. Non-porous pots like glazed pottery and metal boxes retain water. They can smother roots; so make sure there is a drain hole in a pot like this. Low containers that are lightweight are for shallow rooted plants such as azaleas, bulbs and bonsai. Awww, cute little bonsai! Use a large pot for permanent plants like a Japanese maple or conifer, as they need room for 2 years of growth.
Year-round container planting is common for mild climates. Only plants that can tolerate the warmest temperatures your climate dishes out should you grow. In cold climates you will have more success (and a greener thumb) if you pot up annuals for the summer and over winter perennials. On freezing days you can always move them in if there is enough sun or artificial light. You need to do this because the small amount of soil in a pot does not insulate the plant very well. You get to have 100% control with the soil mix, unlike with traditional ground planting.
So, get happy control freaks! This allows you to provide precise conditions for specific plants and better pest managment since different bugs attack different species. The science of soil mixes get pretty involved. In short, you can buy good packaged soil or sterile soil-less mixes. You cannot dig up the same from the ground, as there may be harmful organisms in it. When caring for plants you ought to play it safe submit to their demands for shade, sun, temperature, water, and soil type.
From the Pots to the Plants
Annuals are suited well to containers as they can be crowded in and seedlings can be started inside to extend the growing season. They tolerate a small pot chock-full of plants for a season. Here's a general rule: Plant in container 6 to 8" apart if ground planting specifies 10 to 12" apart. For an annual that will grow 3 feet tall get a pot 24" in diameter. For an annual that will grow up to 1 foot tall get a pot 8" in diameter. Perennials can be grown in containers despite the fact they tend to grow slower and larger. If they outgrow the pot then remove them when they are most dormant.
Some bulbs can be dug up in the fall and stored till planted for an early spring bloom. These plants can be relegated to an insulated garage before cold weather hits. Generally, you prune a plant when it goes dormant and cover its roots since they are still alive. Wrap chicken wire loosely around the pot and pack in straw for insulation and water some in the winter. Plants in this category that bloom for a long time include Lily of the Nile, Peruvian Lily, Asparagus Fern, Coral Bell, Coreopsis, Primrose species and Delphiniums.
Trees, shrubs and vines make you think big, in terms of deep containers, and take on a commitment. These are not a short-term love affair like an annual. They don't need the heavy watering that an annual does. Consider the climate you live in as these plants will have to weather it. The payoff--a small terrace is fashioned with a comfy chair in the shade of a blossoming potted tree. How about those winter berries too? They don't require a lot of feeding, but require the right kind of pruning and watering. Here are a few hardy candidates.
Boxwood: Evergreens that you trim into geometric shapes or use as a backdrop to other plantings.
Its roots are shallow and it grows to up to 10 feet.
Camellia: These ornamental trees sprout big flowers. Thrive in western and southern states and grow slowly up to 7 feet.
Harry Lauder's Walking Stick: Its height is 4 to 6 feet and needs soil that drains. Its trademark contorted branches can be pruned if you are going after a specific shape. But who would want to interfere with its own creative branching?
Redwood: Yes, I said redwood to prove to you that growing trees in pots is more than you would think! It will grow in a large box of 24" wide for a few years "leaving the nest". Prune it to control its height and make it bushier.
English Laurel: This make a dense screen of big leaves. It grows very tall and wide and fast. Often seen as hedges.
Clematis: These vines really like containers but must be moved to a well-protected spot in a frigid winter. It needs a deep pot, but those spectacular blue and purple blooms make its demands worthwhile.
You can harvest many varieties of vegetables and herbs from a large wooden trough as they grow well together. They tend to be sun worshippers. Some herbs put off potent scents; so locating them by doorways and in window boxes would maximize their value to your home.