Container gardens yield many benefits — not the least of which are lovely, low-maintenance landscapes and fresh veggies bursting from small spaces.
“The biggest benefit is that container gardening is great for people without soil to grow in, whether they live in small spaces or have balconies, or HOAs that don’t allow changes to landscaping,” said Brien Darby, manager of urban food programs at Denver Botanic Gardens.
“It’s a luxury to have fresh greens growing, but it’s an attainable luxury,” Darby said.
Laurie Jekel, who founded The Last Detail in 1980, has designed the container gardens at Cherry Hills Country Club for the past 25 years.
“Start small. You don’t have to tackle the whole landscape. Just tackle some pots,” Jekel said. “It’s not that hard, and you can get a big bang for not so many bucks. If you grow veggies and herbs as an urban person, you get truly organic fresh produce.”
Containers add pizzazz to outdoor spaces, delivering almost-instant impact with color, texture and dimension of the pots.
“Containers add height to early-season vegetable gardens with spring kale, mustard, and chard, so it doesn’t look like a flat green landscape,” Darby said. “Lots of us use groupings of containers for the color of the pots. I like bright, primary colors with vegetables.”
Another benefit to pots: gardeners can more easily keep an eye on sensitive plants. Pots help protect delicate species that might get damaged in a landscape or by slugs. Container gardens bring interesting plants closer to eye-level. And smaller pots or those on casters can be moved indoors for protection from hail, snow, or other adverse weather.
“In pots, we do more adventurous annual displays than we could do in the ground,” Darby said.
She designs containers primarily with edibles. In pots, she grows a spectrum of greens. Darby recommends dwarf varieties of tomatoes, peppers, squashes, eggplants and other fruiting plants.
Jekel prefers growing certain plants such as lettuces and basil in containers to avoid slugs.
She said, “Slugs tend not to get in pots.”
Jekel also pots up herbs, annuals, perennials, bulbs, shrubs and even trees. She noted that many plants come back in a pot if they’ve been watered over winter. And Jekel’s container gardens do double duty because towards the end of a growing season, she transplants potted herbs and perennials into the landscape.
In terms of design, containers work well when matched to the architecture of the home and the gardener’s style. The marketplace offers pots in many materials: ceramic, terra cotta clay, frostproof fiberglass, ornamental concrete and zinc. Both Darby and Jekel steer clear of metal pots that can get too hot in Denver’s intense summer heat.
Jekel favors Campania International pots. “They’re expensive, but it’s a one-time investment. They stand up to the erratic temperatures of Denver. Ninety percent of my clients have them. They’re super heavy, so you can even plant trees in them,” she said.
When selecting a plant palette for containers, make sure plants have similar growing habits — especially true for pots in full sun or shade.
Jekel delights in fragrant plants in pots. “It’s so nice when the wind blows or you bump up against scented plants. We all need a lot of soothing in our times.”
When designing container gardens, think of a teepee with the tallest plants at the center and trailing plants at the edges. A common container garden formula calls for combining a thriller (something dramatic), a filler (greenery to fill in the blank spots) and a spiller (a trailing plant) in each pot.
Keys to thriving container gardens:
• Go deep. “If doing veggies, you can get away with 10 to 12 inches deep for leafy greens and herbs, edible flowers, but anything that fruits — tomatoes, squash, eggplants pepper — needs 16 to 24 inches of depth,” Darby said.
• Drainage is essential. Darby is not a fan of creating false bottoms with gravel or other materials. “You run the risk of water build-up,” she said.
• Roots down. “Some plants get very root-bound and they’re strangling themselves,” she said. “We always rip off the bottom of plants from the greenhouse so its dirt and the roots are going down, not in a circle.”
• Mix it up. When growing in pots, use a container mix or potting mix: “It’s filled with a lot of organic matter. It’s light and fluffy, so there’s no soil compaction issue; and it holds water better,” Darby said.
Jekel has used Fertilome potting mix for 37 years.
Darby said, “Definitely refresh the soil before planting. Even if not putting new soil in, dump out the old soil on a tarp and solarize it for a couple of days. It will be less compacted. Ideally, mix in some compost.”
• Water regularly. “Pick a time where you water pots, everyday or every other day after work or whatever, but be consistent,” Jekel said. “Plants need regularity. It’s super, super important. You train the plants; the plants don’t train you. Once a week, use something like Miracle-Gro.”
• Maintain. Container gardens don’t require much weeding, but maintain pots to keep them looking their best. Switch out cool-season annuals when they get leggy. Deadhead summer annuals to keep them flowering. Remove any yellow or brown leaves. Stay on top of harvesting vegetables.