My Favorite Trio For Flower Planters

By Laura Miller | August 12, 2022
by Laura Miller
August 12, 2022

I love bright, vivid flowers. One of my favorite combinations for flower planters is the trio of purple petunias, pink cockscomb and yellow marigolds. The vibrant hues of these three flowers are attractive, but when planted in combination they create eye-catching interest in the garden.

Designing Flower Containers

I hate to admit my age, but my early gardening days predate the information highway that is the internet. Thus, it took me several summers of trial and error before I was able to create an attractive potted floral design. I eventually did stumble upon the design idea often referred to as thriller, filler and spiller.

The thriller is a spiky or upright species that gives planters vertical definition. The filler is a flower which dominates the mid-area of the planter. It’s not as tall as the thriller and usually has a rounded or bushy type of growth. Finally, the spiller is a vining or crawling type flower that flows over the sides of the planter.  

Purple Petunias

With dozens of petunia colors, patterns and textures from which to choose, deep purple petunias that have velvety flowers are my favorite. When planted in a container, petunias spill over and soften the rim of the pot. Regular deadheading makes petunias one of the container flowers that bloom all summer long.

Petunias are fairly easy to keep looking nice. They prefer full sun exposure of at least six hours a day. Anything less and they will not bloom as profusely. I also find twice-per-day watering during hot weather is necessary to keep petunias and other container flowers in bloom.

When growing petunias in containers, I like to keep them in a sheltered area. Petunias have very delicate flowers that are easily damaged by heavy rain. They quickly produce new flowers, but it can take several days before they open.

Pink Plumed Celosia

Cockscomb comes in a variety of flower colors from yellow and orange to burgundy pink. I prefer the darker shades of pink for my favorite container trio. Like petunias, celosia prefers full sun.

When planted in a container flower garden, celosia tends to produce narrower blooms than when planted in the ground. Since cockscomb provides the spiky aspect of a flower pot, I prefer varieties that reach 12 to 15 inches (30 to 38 cm.) tall.

For container plantings, I usually purchase my flowers rather than starting them from seed. I look for healthy, pest-free plants and I prefer to buy them when they have at least one open bloom. This is especially important with celosia as most years my local greenhouses only offer it in mixed color packets. 

Yellow French Marigolds

For my flower planter trio, I prefer solid-colored, bright yellow French marigolds. Dwarf bush varieties, like Lemon Drop, produce an abundance of flowers on plants that average about 8 inches (20 cm.) tall. This height works well with celosia and petunias to provide the filler feature in a flower planter.

Like petunias and celosia, Marigolds prefer full sun and moderate water. Removing spent flowers encourages marigold plants to retain a bushier shape. As with the other two flowers, deadheading also keeps the planter looking nice and encourages more blooms.

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