Planting containers for the garden or patio can be intimidating, but needlessly so. When it comes to pots, all that hard-won education about "planting with proper spacing" should be tossed out the window. Unlike a newly planted garden, the goal for a container is that it look "finished" when you step away from it. Avoid having it look like it needs several months to "grow into itself." Don't worry. Even if you pack that pot full, with proper watering, grooming and, most importantly, fertilizing, your creation can look just as good in September as it does the day you potted it.
Selecting plants for your pots can be just as fun as planting them. Having grown trough gardens for several decades, I started to think outside the pot. These large stone or concrete containers hold alpine plants, conifers and miniature shrubs and stay outside year-round. I wondered if smaller containers could sit just as happily (and permanently) as my troughs.
I began to experiment using "cheap" shrubs mixed with houseplants and/or annuals and perennials, and a variety of pots, some of them made of foam, fiberglass and even heavy glazed pottery. (I never use plastic. I dislike the look of it.) What I found is that most of these plants and the pots will survive quite well without any winter care. (Yes, you'll lose a few pots, but the loss in my garden has been minimal.) Of course, if you use tropical plants or annuals, they will not make it through our winters, but you can always leave space in a pot for a pop of annual color and change it up from year to year.
There are pots that will not winter here. Cheaper glazed pots will sometimes split, and terra cotta will spall or crack. I avoid those, only trotting them out after chance of frost is over.
The only definite consideration you need when pulling together plants for your creation is that your chosen grouping require the same light exposure. Also think about the light the pot will receive where you place it in your garden and plant accordingly. After that, the sky is the limit.
Size matters when you expect a plant to weather the winter in a pot. The pots I leave outdoors are large. Many of them are used as backdrops for smaller pots. I've also become quite interested in texture and have veered away from flowering specimens, using things such as barberry, cotoneaster, arborvitae, spirea, juniper and boxwood. Most of these common shrubs can be found very cheaply in many different sizes. Approach your creation like a flower arrangement. Don't be afraid to accessorize it or rework it. If something doesn't thrive, remove it and replace it with something else. I tweak containers endlessly, right up until frost. That's part of the fun.
When looking for possible container plants, don't overlook indoor/house plants. They can add great accents to the outdoor mix and most will thrive outside during the summer. A large pot full of snake plant will make a great vertical accent. Mix and match them with annuals and conifers. The benefit here is that you can take them indoors in the fall and then repurpose them next season.
When planting, use a good quality container mix, which is usually soil-less, and a granular slow-release fertilizer. I use a product called Dynamite, a balanced fertilizer (13-13-13), which I am forced to order over the Web. This fertilizer, for me, is the key to container gardening, and I can't live without it. It will ensure that plants will keep growing and thriving within the confines of a pot after nutrients are leeched out of the potting mix during watering.
Watering is another key to good containers. In the heat of the summer, pots are watered every day, in high heat, sometimes twice. I also groom containers. Those with annuals in them such as petunias are given severe shearings when they start to become leggy. Think crew cut here. While this may seem draconian, you will be surprised at how rapidly plants will flush-up with new growth, rewarding you with more blossoms and a lush, newly planted appearance. Flowering plants, such as geraniums are deadheaded regularly, encouraging new blooms.
I get several years out of my conifer/shrub pots without the need to renovate. By the time they need refreshed, I'm bored with them anyway. But inevitably, things will start to appear leggy and unkempt. No worries. Just tear the pot apart. In many instances, you will be able to rework most of the plants into another arrangement. This year one of my more "scraggly" specimens "spoke to me" as I yanked it out of the pot. A little selective pruning and it is now a faux bonsai in a smaller glazed pot, top-dressed with pea gravel.
Finding pots: Keep your eyes open. Once the season progresses, you can usually find great deals. Box stores, nurseries and even drugstores will be selling off seasonal merchandise. Craft stores will often discount their pottery to move it. In fact, this past week a local store was offering 70 percent off its entire pot selection. Keep a selection of pots of various sizes. Remember: Just because you have it doesn't mean you need to use it.
Groupings make a bigger impact than one or two pots. The rule of three is in play here, odd numbers being more pleasing to the eye. Try to group pots that are different heights and sizes. Three of the same type of plant, such as acid-green spireas, in different size cobalt blue or black glazed pots are a stunning accent. Spireas are cheap, easily found and are extremely tough to kill; I have yet to murder one. A quick shaping with the shears in the spring and the plants are ready for another season.
Using the same type plant throughout your pots, such as spirea, can help tie multiple container groupings together with a common theme.
Scale is another essential consideration and possibly the most important element when placing containers. Look at the pot in connection with its surroundings. Small pots by an entryway will be dwarfed by the door and are not pleasing to the eye. Larger is usually better, and larger pots also have the benefit of being easier to keep watered once the very warm weather sets in.
Let your creativity rule the day. This isn't rocket science, but it is fun!
Post-Gazette garden editor Susan Banks: email@example.com or 412-263-1516.