Gardening in containers is fantastic for many reasons. It makes gardening more accessible and it can make gardening more convenient since you can keep containers close to the house. It also gives you almost endless styling opportunities for your outdoor space. Container gardens are great as well if you live somewhere with a lot of rain, like the “wet” coast of Canada, since you have more control over drainage.

How To Design Plant Combinations for Container Gardens

The classic thriller, filler, spiller container garden recipe is a reliable plan when it comes to plant combinations. But if it feels a little limited, like you have to have spillers or a tall thriller, you can break down the concepts of each element and interpret it in totally different ways that suit your personal style

Thriller plants are often interpreted as something tall and showy in a planter. This usually means plant combinations of things like ornamental grasses, canna lilies, or dracaenas with trailing plants around the base. But thriller can be translated in many different ways. It could mean plants with vibrantly coloured flowers, huge leaves, or a unique texture. Your thriller doesn’t even have to be a plant; it could be an architectural or structural design element like an obelisk.

Filler plants are often mounding plants like sweet alyssum, coleus, or marigolds—plants that fill in a container garden’s mid-height. But filler plants aren’t just mid-height flowering plants. They could be ornamental grasses as a background to a vibrantly coloured thriller plant. And many filler plants look great as specimen plants, filling an entire container on their own. You can also use non-plant items as fillers, like mirror globes or fairy garden elements, to create a vignette in a container.

Spiller plants are generally things like silver falls, creeping jenny, or sweet potato vine. They usually trail down over the edges of your containers. But sometimes, a hanging basket full of a single kind of trailing plant can be stunning all on its own. Or, if you want to feature the beauty of a stylish planter, maybe you want to skip spillers entirely so you don’t obscure the planter. 


The thriller, filler, and spiller concepts can also apply to colours or textures instead of plant sizes. Your plant combinations in your container garden could be a large-leaved thriller with finer texture fillers and spillers. Or you could have colour combinations with plants that help to emphasize the colour of your thriller plant. 

We often default to planting in concentric circles in round planters and squares or rows in square containers, but you don’t have to follow that typical pattern in your container garden. You could plant your tallest plants at the back of a planter, mid-height ones in the middle, and short ones or trailing plants in the front. Or, you could plant your spillers over the sides of your planter.


Another thing to consider is how you will position your planters. The thriller, filler, spiller plant combinations could be applied across multiple containers as well, featuring thrillers in one planter, fillers in the next, and spillers in another. Or, if you had a row of containers, you could feature thrillers or tall plants on opposite ends of the row, then fillers next, and spillers in the middle. Or the opposite. 

Window boxes are planters that often benefit from planting styles that don’t follow the thriller, filler, spiller concepts. Many plants look fantastic in window boxes, like:

  • Pansies
  • Violas
  • Sweet potato vine
  • Petunias
  • Calibrachoa
  • Creeping Jenny
  • Fuchsia
  • Impatiens
  • Licorice plant
  • Dichondra ‘silver falls’


You often see window boxes where every box is planted identical to the one beside it. You can do that, and it is a default and simple way to provide balance or symmetry to your curb appeal. But that’s not the only way to give visual balance to your home. You could plant with varying heights from left to right or paint a rainbow by planting different colours of the same plant across a row of window boxes. 


How you style them and what plant combinations you use in your containers also depend on where you’re going to put them and the planter’s style. If you have window boxes, you may want to skip tall plants entirely, or you may want to stick with a single kind of plant for the entire box. 

Break the Rules of Container Garden Plant Combinations

Go ahead and break the “rules.” You don’t have to follow the typical symmetrical or hierarchical container garden plant combinations. Plants do have particular cultural needs, so it is good to consider each plant’s needs for water, fertilizer, and sunlight when deciding on plant combinations. But, you can break all the usual design rules however you want. 

Get creative with your container garden this summer. Search for some creative ideas online, or take inspiration from art or design that you love. Whether you’re looking for inspiration or you know exactly what you need, stop by Mother Nature. We’ve got a fabulous collection of plants coming in this spring, and we can’t wait to see what creative things you do with them this summer. Tag us on Instagram or Facebook so we can see your creative container gardens!