I recently taught a container planting class through the continuing education program in my community. It was so much fun sharing the tips and techniques I’ve acquired over the years and even more exciting to see what my “students” created. Everyone walked out with a unique planter – or basket, or milk crate – filled with a variety of annuals, herbs and perennials that they might not have previously thought to put together.
Without a doubt, container planting is one of my favorite aspects of gardening. You can overcome less-than-ideal site conditions, experiment with new plants and create “theme” gardens of plants that might otherwise clash in your existing beds.
Let’s say you have your heart set on a plant that needs more sunlight than your garden receives. Chances are there is a sunny spot on your property that would be the perfect place for a container. Same for difficult soil conditions. In a container you can custom-blend a soil mix, creating the perfect environment for a coveted plant that wouldn’t thrive in your garden’s soil.
Typically, container gardens are home to annuals only. But a window box or pot makes a perfect “trial home” for a perennial, so you can try out a new plant before adding it to your garden. Many shrubs – hydrangeas, spruces and roses, for example – are available in sizes that are perfect for a planter. Ornamental grasses provide an unexpected element when taken out of the garden background and placed prominently in a large pot. And invasive plants (like mint and bamboo) that would overtake a perennial bed remain well-behaved in a large container.
Planters are ideal for creating “specialty gardens” that might not work in your existing beds. A rock garden of succulents and small conifers that would be incompatible in a cottage-style bed would make a striking accent in a concrete urn on your patio. A kitchen garden of herbs becomes impractical if you have to walk some distance from your house to your garden. But a window box or pot right outside your kitchen is an ideal spot for seasonal plantings of basil, oregano, rosemary and chives.
How to begin? Here are some basic design principles and installation/maintenance tips to get you started:
What to plant: my containers typically include a combination of plants that are vertical (to provide a focal point), surrounded by “filler” plants with a more mounded shape and finally trailing plants to spill over the edges. This creates an effect that is interesting yet cohesive.
When choosing a color scheme, the most fail-safe option is to go monochromatic. If you would like to mix colors but are still tentative, white/yellow/blue is a classic garden color scheme that always looks great.
How many plants to buy: As containers are seasonal, you want instant results – plant generously for maximum impact. I always bring a list of container measurements and a measuring tape to make a mock arrangement of the plants at the nursery before purchasing.
Installing plants: Make sure that there are drainage holes in the bottoms of your containers. Add your potting mix, selecting one designed for container use (for optimal drainage). Next, add a slow-release fertilizer and water-storing polymers. Polymers absorb up to 200 times their weight in water, releasing moisture back into the soil as it dries out. Because pots and containers can dry out very quickly, polymers provide extra insurance during very hot/dry spells. Add your plants, some more potting mix and a final layer of mulch to retain moisture, regulate soil temperature and give a neat and finished appearance.
Maintenance Regular watering is your most important task – plan on daily watering, depending on the size of the pot and the weather. Try to water early in the morning to ensure that your plants have adequate moisture as the day heats up.
As the season progresses, check on the vitality of your plants. While some plants can last from late spring till fall, others will need to be replaced mid-season. Don’t hesitate to replace plants that are looking tired and spent of blooms. By making periodic changes you can have the pleasure of beautiful pots and window boxes all year long.
Most importantly – have fun! Container gardening is an ideal opportunity to take chances and experiment with new color schemes and plant combinations. Pots are relatively quick and easy to install and provide almost instant gratification (not something commonly associated with gardening!).