container-garden tips, with bob hyland

Phormium and succulent pots by Hyland Garden DesignUSUALLY ON MEMORIAL DAY or thereabouts, I teach a series of container-garden workshops in my garden with my longtime friend Bob Hyland, a garden designer and former public-garden administrator and nursery owner who always dubbed our duet “Contained Exuberance.” Want to take your pot designs up a notch this year, without getting overwhelmed? Read (and listen) on:

Bob was VP of Horticulture at Brooklyn Botanic Garden before opening Loomis Creek Nursery a few minutes’ drive from me about 10 years ago.  He has since relocated to Portland, Oregon, and debuted a new container-garden business in 2013 in South Portland. It’s a 4,500-square-foot indoor-outdoor pop-up shop specializing in great containers, ready-to-go pot designs, and plants for containers, too, in collaboration with the until-now-wholesale-only growers at Xera Plants. (Bob still designs gardens, too–in a pot or not!)

prefer the podcast?

CONTAINER GARDENING was the topic of the April 29, 2013 edition of my weekly public-radio program with guest Bob Hyland. Listen anywhere, anytime: Locally, in my Hudson Valley (NY)-Berkshires (MA)-Litchfield Hills (CT) region, “A Way to Garden” airs on Robin Hood Radio’s three stations on Monday at 8:30 AM Eastern, with a rerun at 8:30 Saturdays. It is available free on iTunes, the Stitcher app, or streaming from RobinHoodRadio.com or via its RSS feed. The April 29, 2013 show can be streamed here now. Robin Hood is the smallest NPR station in the nation; our garden show marked the start of its sixth year in March 2015.

‘keep it simple’ doesn’t mean boring

LET GO OF THE “IDEAL” that is so often seen in books, magazines, catalogs—the notion that you can have 7 or 9 or 10 kinds of plants in one container “all perfectly blooming in unison and perfectly coiffed,” as Bob describes this semi-fantasy.

Let go of the notion, too, that annuals are exclusively what belong in pots. Anything can be planted in a pot: perennials, for instance. “A big juicy hosta in a pot can be quite dramatic,” says Bob. “It lifts that hosta above the ground and really accentuates it (and may help keep it away from slugs and snails, too).” So can euphorbia and heucheras or heucherellas and hellebores (below, a shade pot of Heucherella ‘Sweet Tea’ and Euphorbia ‘Blackbird’ and  Euphorbia characias subsp. wulfenii and Helleborus ‘Ivory Prince’).

Container of euphorbia and heuhera by Hyland Garden Design

Shrubs work, too. “I like to think of the four seasons, even in my container designs,” says Bob, “so for instance all those shrubby dogwoods with showy leaves in summer and bright twigs in winter are great for year-round containers.”

Think of a stunner such as the white-variegated red-twig Cornus alba ‘Ivory Halo,’ he suggests, in a wine- or whiskey-barrel sized pot of any weather-proof material, such as faux concrete or faux terra cotta.  (That’s ‘Ivory Halo’ in the left-hand pot in the photo below on this page.) Or plant not-quite-hardy shrubs and small trees in pots that get tucked into the garage in winter (as I do my Japanese maples, and a friend nearby does a collection of unusual hydrangeas). Even evergreens: that’s the Japanese holly called ‘Sky Pencil’ in one of Bob’s client’s pots, below.

‘choose plants carefully’

Shrub, silver sage, dichondra in pot by Hyland Garden Design

TAKE THE CONVENTIONAL three-plant container-design advice of “spike, filler, spiller” (a.k.a. “thriller, filler, spiller”), and improve on it by selecting better-than-conventional plants.

Oh, sorry–what does thriller, filler, spiller mean? The “thriller” or spike is the architectural element, “the vertical oomph;” the filler is the medium-sized plant in the mix. “The classic filler is a geranium,” says Bob, “and it gives us some volume and uniform color for the design.” And then you have something that spills and trails–things that break the edge and soften the pot, such as sweet potato vine, or alyssum, “or real spillers that really drop vertically, such as Dichondra ‘Silver Falls,’” above, trailing over and onto the pavement by late-season. Tradescantias and plectranthus are two of his other favorites.

“I like to think in simplistic terms,” says Bob, whose designs nevertheless look anything but simplistic or commonplace.  “I think it’s better if you just think of those three plants and choose wisely.”

Don’t shoot for the unrealistic “happy 9-some” of all those magazine photos staged for the occasion of a photo shoot, he says, or the giant containers at public gardens with expert staffs to groom them, and greenhouses that can produce backup plants for later fine-tuning and swapping out. Start with the basic three, and then maybe add one or two more at most.

“I think when you start getting above five it gets too complex,” Bob says. “Are they all compatible; will watering or the same other care make everyone equally happy? And there’s usually a thug in the group that will try to take over.”

Again, though: Choose wisely. Expand your definition of the “thriller” to include yuccas, perhaps, or cordylines and phormiums (the spike in the top-of-the-page pots is the phormium called ‘Flamingo,’ growing with Sedum nussbaumeranumSenecio ‘Kilimanjaro’ and Kalanchoe pumila ‘Dwarf Blue’). “These really giant architectural forms are hardy out in Portland, in the ground or big pots,” he explains of the modified Mediterranean climate he’s gradually learning to garden in, where no measureable rainfall happens from June 15 to September 15 in a “typical” year. Elsewhere, such tender beauties can be stashed indoors with some success.

Or try two of Bob’s other favorites as your architectural moment, ones you can use as one-season “annuals:” cardoons or artichokes, often sold in the vegetable department of the garden center. He loves silvery foliage, including not just the cardoon (Cynara cardunculus), for instance, but also silver sage, Salvia argentea, with its basal rosette of furry leaves (again, in the pot with ‘Sky Pencil’ holly and the Dichondra. “A one or two or threesome becomes like a ‘bow’ in your pot design,” he says.

choosing potting soil

AND THEN THERE ARE the basics, the how-to steps. Such as: What is a good potting soil?

“Generally when you open a bag of potting soil, they’re too fine—too much peat moss–and then they become heavy and sodden,” says Bob (and Margaret). “I like to find one with more shredded bark, which also reduces my use of non-renewable peat resources.”

Look at the little recipe on the label, he says—and watch out for ingredients you may not want, such as added chemical fertilizer that may be lurking.

If you can’t find good-textured commercial mixes locally, beef them up a bit by working in some composted leaf mold in the bottom of containers, or mixing in other compost. (I use some of my relatively fine-textured composted mulch made from stable bedding.) We are talking about adding texture, not making them heavy so they get mucky and stay wet too long.

  • Bob’s and my complete set of tips on “Contained Exuberance” can be found at this link.
  1. Nadia@Loveliveandgarden says:

    I think that first tip to ‘let go of the ideal’ is the essential one. Should doesn’t exist. When we start thinking about how things should be it stops us from moving forward on the plan. Great post.

  2. Teri Weaver says:

    My challenge with container gardening is the container: they can be so expensive and so heavy. I keep scouting garage sales for abandoned pots, but nobody seems to give these up. Any thoughts?

  3. Linda Kampel says:

    Thank you for the great post Margaret. The planters are beautiful! I’ve been a container gardener for a long time. I’ve used many things as containers. The latest being a well aged galvanized trash can. I wish I lived closer so that I could attend one of your workshops.

    1. margaret says:

      You’re welcome, Linda. Galvanized is great — love such vessels!

      Hi, Brian. Good suggestion. I should explore a source for it myself.

  4. Brian O'Toole says:

    A terrific soil amendment that can be added to pots is vermi-compost. I always include a 20% mix in my potting soil and it provides an organic, natural fertilizer for the plants. With stronger root growth and vigor, my pots need less watering throughout the summer, and are generally more resilient to weather…..and I typically have 100% survivability of my transplants. Loved your posting for potting plants….great ideas!

  5. Lorie says:

    You made my day. This is the first year filling my 3 hyper tufa troughs with succulants with a corkscrew in the middle to see if I could pull it off. With days and days of rain, they are draining beautifully. Great choice for big containers is “Big Red Judy” coleus (does get big, but excellent in sun or shade) combined with chartruse anything(s) else. Absolutely weather proof.

  6. Dahlink says:

    Hmm–I just went out and counted the categories of plants in my biggest containers–7 (more if you count each color of petunia separately)! They seem to do fine with a perennial ornamental grass as the “thriller” and a spreading ground cover that allows me to tuck in the annuals for summer color.

  7. Laura says:

    I’m always on the look-out for container combinations. Your post has given me some new ideas to try. Thank you.

  8. Sherri says:

    I’ve been searching for potting soil recently and can only find bags with fertilizer added. Texture is not the issue. Any suggestions for making my own?

  9. Weston Perry says:

    I’m on year three of container gardening, and was looking forward to stepping up a level, but with a relocation imminent, I’ve done only herbs and a couple of plants that came back without any invitation or encouragement.

    I love the garbage can idea! I’m using 5 gallon pickle buckets. They are not pretty, but I’ve staggered their height and put a row of lower terra cotta pots in front to conceal the plastic. The plants are loving the extra soil and individual plants are producing more than my little household can consume.

    1. margaret says:

      Hi, Weston. Anything can be a “flower pot”! And K agree: you can fake it/conceal less-pretty ones as you suggest. Thanks for saying hello.

  10. Lindsay says:

    I want to plant in containers in zone 7, TN and be able to leave the plants (camellia, shasta daisy, and yucca)outside year round. Would these be ok in pots, if so, what kind of material should the pot be made of?

    1. margaret says:

      Hi, Lindsay. The pots have to be large, and frost-proof so they offer the plants enough insulation (large volume of soil) and also don’t crack. Many choices from wood barrels to fiberglass and other faux materials, concrete and metal…

  11. Jacquie says:

    This is a great article and so timely since I’m now starting to think about my pots in northeast Ohio and what I want to plant. Will have to wait a little longer as our danger of frost has not passed. :-(

    Every year I try to do something different as I’m usually in a bit of a rut doing the same things year after year. I end up with the same things because of certain flowers that are my favorites. I guess we all have favorites, not only because we love how they look but also how they perform in our zone. Many that I choose have performed well over the years and Are reliable.

    After reading your article I am now inspired to include some perennials in my larger pots which I
    have never done. Now I am REALLY excited about trying something new. Thank you for inspiring me! For sure a coral bell; one of my favorite perenniels will be in one of my pots. I never thought of doing that. It will be fun to think about what to put with it.

  12. Leslie says:

    Hi Margaret, A question, really. I dumped a large ceramic pot yesterday to refresh the soil and found a million or more ants at the bottom – a real nest! Thoughts? I dumped the contents in nearby brush, but is there a way to prevent this? It has happened before.

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