It’s not for nothing that more and more varieties of sedums can be seen at garden centers each year.
The ones I planted last spring in pots and ignored all winter – not protected in the garage but out in the elements – rewarded my neglect by springing back green and robust once the weather warmed. Needless to say, I will be adding more pots of sedums to my landscape this summer, mixing and matching their waxy leaves in various sizes, heights, spread and color.
They aren’t the only container plants that will ease the demand on watering this year. And after the last two summers, we all are looking for drought-resistant annuals and perennials for our container gardens. While most containers need to be watered once every day or two – or more often if the pot is small – there are ways to reduce watering needs even in these little patches of garden real estate.
Start with the pot
Most of us have a slew of little terracotta pots lying around, and they help to catch the overflow of the overbuying we do at the garden centers each spring. But then we have to water them.
Instead, invest in the largest container that you can afford that matches your decor, advises Norman Warminski, a retired extension agent who now works seasonally at Tree Top Nursery. Because large pots have more soil mass, they hold water longer. They also make more of a statement.
Next, choose a pot that’s made of plastic, ceramic or concrete, Warminski says. “It’s a little more pricey, but they also have more insulation. It’s more of a durable pot.” Terracotta is pretty, but moisture is lost through its pores.
Warminski doesn’t consider hanging baskets to be very drought-tolerant. “You have a smaller container usually. And they’re in the air where there’s more air circulation.”
Move on to the soil
A good-quality, fluffy potting soil is recommended for growing plants in pots. But because its drainage is so good, it requires more water than the soil in the ground. You can increase the moisture it holds, though, with a product such as SoilMoist, polymers that form a jelly-like substance in the soil.
Incorporate the SoilMoist into the soil before planting, and be careful to use the amount recommended on the label for your size pot. Put in too much, and the polymers froth out.
But if you use drought-resistant plants in your pots, you won’t want to use SoilMoist, Warminski says, because it could hold too much moisture.
Master gardener Peggy Griffith, who owns Ladybug Landscaping, recommends top-dressing the soil with mulch once a pot is planted, and never fertilizing when the soil is dry.
Select drought-tolerant plants
Native plants that can be grown in the ground should be considered fair game for containers, too, Warminski said. “I think a lot of people miss out by not using some of the native shrubs, even like a sumac,” he said.
Here’s a list of container plants that Warminski and Griffith have found more drought-resistant than others. It’s good to combine plants with like needs in the same container, so consider mixing and matching these. Plants that need to be grown in the shade generally need more water than those that need the sun, Warminski said, so all of these plants should be grown in the sun.
• Purple fountain grass or other tall ornamental grass
• Upright varieties of lantana
• Sun coleus (believe it or not, Griffith says)
• Dusty miller
• Dahlberg daisy
• Zinnias such as the Profusion series
• Blue fescue such as Elijah Blue
• Globe amaranth
• Succulents including sedums
• Gold trailing lantana
• Rose moss (portulaca)
• Sweet potato vine
• Ice plant
• Variegated Swedish ivy
• Vinca vine
• Black-eyed Susan vine.
Many herbs also work well in pots; they and sedums should not be fertilized.
Despite the fact that these plants hold up fairly well in the dry heat, “you’re still going to have to water, at least every day or every other day” when plants are in containers, Warminski said. But if you’re adding SoilMoist or switching to non-terra-cotta pots or growing sedums for the first time, also be careful not to overwater, which can produce results similar to watering too little.