After a long winter, spring’s arrival makes gardeners giddy. We’re ready to race outside, get our hands in the dirt, and create gorgeous gardens! However, for many areas, snow and freezing temperatures continue well past March 20, and the soil remains frozen. What’s an eager gardener to do?
Plant a container garden!
While tender annuals require warm, frost-free weather, planting a perennial container garden in early spring serves two great purposes: first, you get much-needed garden therapy to combat winter weariness; and second, you’re jump-starting the garden season, allowing the perennials to settle into their new home so they’re ready to burst into bloom as the weather warms. Here are a few tips, plus three perfect perennials, for creating a great spring container garden.
Step One: Container Considerations
Before you start planting in an old pot you found in the garage, consider investing in a container that withstands freezing temperatures. Terra cotta, ceramic, concrete, and other moisture-absorbing materials may crack when temperatures drastically drop, as the water expands with freezing conditions. However, fiberglass, metal, plastic, wood, and “terra cotta-like” containers labeled to withstand extreme cold offer good choices for your spring container garden.
Also, remember: bigger is better when selecting a container. Because you’re planting a perennial container garden that can last for years, choose a container with ample space for growth. The perennials may eventually outgrow the container after a few years, and you can then plant them out in the garden or in a second container. However, to ensure healthy plants, use a large container filled with high-quality potting soil so the plants’ roots have plenty of room to grow. Along with ample space, a large container tends to retain more moisture than a small pot, which means you’ll spend less time watering in summer’s high heat. (Small containers often require twice-daily watering during summer!)
In addition to proper material and adequate size, make sure your container contains drainage holes to keep the plants healthy. Roots that sit in water can rot. If you’ve fallen in love with a pretty container without drainage holes, no worries—carefully drill holes in the bottom!
Step 2: Select High-Performance Perennials
When you’re creating a container garden, designers recommend a “thriller, filler, spiller” approach to choosing plants. The “thriller” is a taller, showy plant that adds height and vertical interest to the container garden. The “filler” is just as the name implies—a mid-sized plant that “fills” the container with pretty foliage and blooms, adding a lovely layer under the “thriller.” The “spiller” cascades over the sides of the container, adding a perfect pop of color or texture to the arrangement.
When selecting plants, think about both color and texture. Choose either complementary colors—those colors found opposite one another on the color wheel—or analogous colors, which are colors found next to each other. Complementary colors, like purple and yellow, add drama and high contrast to container gardens, while analogous colors, like pink and lavender, provide a more serene, tranquil feel. Remember to consider interesting foliage colors when selecting plants, too.
Decide where your container will grow. Is your garden space sunny or shady? Select plants appropriate for the amount of light your container garden will receive. To create a spring container garden that blooms into summer, try the following combination for a sunny-space container garden:
Thriller: Penstemon ‘Prairie Twilight’ (pictured, right)
Also known as beardtongue, the dense clusters of delicate, tubular pink flowers with white tips and throats bloom from spring until August. The tall flower stalks attract butterflies, bees, and hummingbirds, too!
Filler: Achillea ‘Ritzy Rose’
Deep-rose blooms mature to pink with light eyes, which pair nicely with the colors of ‘Prairie Twilight.’ Plus, the fern-like foliage and compact habit make it a terrific choice for filling the container with color and texture.
Spiller: Campanula ‘Blue Waterfall’
The cascading habit makes ‘Blue Waterfall’ an outstanding choice for containers. The plant lives up to its name, with a wave of dense blue flowers spilling over the edges of the container. Pollinators love this bellflower, too.
The number of plants and their placement depends on your container size and site. For a 20-inch diameter container, for instance, you’ll want one thriller, three fillers, and 4-5 spillers. You may be tempted to add more plants, but remember—these perennials need room to grow and will soon fill the container beautifully.
If you’re placing the container against a fence or wall, plant the thriller in the back of the container, add the three filler plants in a semi-circle around it, then place the spillers along the three visible edges of the container. If the container is positioned where all sides are visible, place the thriller in the center, stagger the filler plants around it in a circle, and plant the spillers along all edges of the container.
When planting the container, choose a high-quality potting mix with a slow release fertilizer. Fill the container approximately three-fourths full with potting soil. Gently remove the plants from the nursery pots, loosen the roots, and place the plants in the arrangement you’ve chosen. Add more potting soil to cover the plants’ root balls and firm the soil around the roots. Make sure that the soil level remains an inch or two beneath the rim of the container so that the soil doesn’t spill when watering. Water well to settle the plants.
Step 3: Container Garden Care
Check your container garden often to see if it’s time to water. Stick your index finger an inch into the soil. If it’s moist, terrific—no water needed! But if it’s dry, it’s time to give your plants a drink.
Feed plants with a slow-release fertilizer to keep them healthy and blooming. Because of frequent watering, nutrients leach out of the container’s soil. Follow the directions on the fertilizer’s label to keep your perennials healthy and well-fed.
Also, for season-long blooms, deadhead faded flowers. Not only does deadheading encourage the plant to produce more flowers, it also keeps your container looking attractive and tidy, too.
There—now don’t you feel better, knowing that you can get your hands in the soil even while the weather is chilly? Enjoy a respite from the cold while you plant your spring container garden!
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