I Used to Plant and Hope. But There's a Better Way!
- Diana Pierce
- May 27
- 4 min read
By Diana Pierce | May 27, 2026
I’ll confess: I’ve been known to spot a pre-planted pot at the garden center, pick it up, and consider my container to-do list... “done.”
Not this year.
This year I wanted to push myself. I wanted new plants for sun and shade, combinations I hadn’t tried, containers built from scratch. I’m not a beginner, but I had plenty to learn. So after planting my entryway with shade plants and loading up my patio with spring choices, I started to get nervous. Too many plants in the brown container on the patio? Not enough at the entry? When I wanted a critique, I went straight to the expert — Michelle Mero Riedel.
Michelle Mero Riedel is a University of Minnesota Extension Master Gardener, a writer and photographer for Northern Gardener magazine, and one of the most sought-after garden speakers in the region. She photographs her own work, so she sees containers the way a designer and a photographer do at once. I sent her my photos and asked her to be honest. She was.
On That Awkward May Look
Diana: When people first plant containers in spring, why do they often look awkward or unfinished?
Michelle: Buy plants in three or four-inch containers rather than plant packs. Those larger plants are vegetatively propagated, grown from cuttings, and bred to perform all season long. Plant packs are grown from seed and start out much smaller. When everything in a pot is the same size, it looks full and cohesive right away. Mixing seed-grown plants with larger ones just reads as awkward.
On the Thriller - Filler - Spiller Formula
Diana: What’s the biggest misconception about Thriller-Filler-Spiller containers?
Michelle: That it’s a rule because it’s not. It’s a classic design concept, and a useful one for beginners. But anything goes. Some pots look great with all plants the same height, or just fillers and spillers, or even a single species. I do 20 to 25 containers a season and only some follow the formula. Start with the concept, then make it your own. Mid-to-late season, you can always add or subtract plants.
The Honest Critique
Diana: Looking at my two containers honestly, what’s your critique?
Michelle: The front entry container is all foliage right now. Ivy, asparagus fern, the face pot with grass. It needs color. A small coleus, begonia, caladium, or New Guinea impatiens would be a beautiful addition for a shade spot. They can handle low light and will give you something to look at all summer.
The patio container in the brown pot gets an “A.” The mix of pansies, alyssum, coral bells, and dianthus shows a good eye for varying flower shapes and a cohesive cool color palette — pinks, purples, whites. When the pansies fade in summer heat, pull them out, step back, and let the remaining plants fill in. You might like what you see.
On Balance and Color
Diana: What makes a container feel balanced instead of messy?
Michelle: The Thriller-Filler-Spiller structure gives you built-in balance through varying heights. Beyond that, a good pair of shears is your best tool. These bred plants respond beautifully to haircuts and fill out horizontally when trimmed. Color scheme matters too. I group warm tones together like yellows, oranges, reds, and keep cooler tones in their own pot. Green works with everything, and not every plant needs to flower. I love pairing blooms for color with bold foliage for texture.
On Late-Season Surprises
Diana: What plants tend to surprise gardeners with late-season growth?
Michelle: Elephant ears start at six inches and can reach leaves of 30 inches by fall. Coleus can grow four times its purchase size. Sweet potato vine goes from six inches to six feet. That growth factor is exactly why you don’t need to overplant in May. Let the plants do the work.
On Difficult Conditions
Diana: What are the hardest conditions to design for?
Michelle: Deep shade is the hardest and the nursery selection is simply limited. I borrow from my garden: hostas and astilbes divide beautifully, and coleus is my workhorse for shade. Spider plants and dracaenas from inside the house work too. Full sun is actually the easiest and most nursery plants are bred for it. Just plan to water generously and use a large pot. For windy spots, anchor tall architectural plants like elephant ears or ornamental grasses with a heavy stone at the bottom of the container.
On Plant Choice and Patience
Diana: How much of container success is plant choice versus patience?
Michelle: Both matter equally. Choose plants with compatible light requirements, and think about placement — trailers at the edge, tall plants in the center or back.
But at planting time, you’re always making educated guesses. The picture reveals itself over the season. Keep a garden diary. Photograph your pots. Note what worked and what didn’t. That record is what makes you better every year.
On the May Panic
Diana: What should Minnesota gardeners not panic about in May?
Michelle: I’m always in panic mode in May. I have plants ready to go but I’m not willing to leave them out when overnight temps dip into the 30s. I’m moving them in and out of the garage as needed. In Minnesota, the safest approach is to wait until the third or fourth week of May to plant containers. I know it’s hard when the nurseries are full and everything looks so good. But that patience at the start pays off all summer long.
So, I took Michelle’s advice. The brown container on the patio? I’ll change that out when the pansies are done. The entry? I see a trip to the nursery in my future. But, for now, I consider my to-do list... done.
What about you? Have you had the same questions?
Where do you turn for advice?
See you in the garden.
Diana
© 2026 Diana Pierce
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