Anatomy of an Outdoor Planter

We have yet to start landscaping our backyard, so this spring I planted over a dozen containers for our outdoor space. The fresh flowers and greenery instantly transformed our patio while also satisfying my newest obsession in gardening.

Whether you’re just getting started or looking to supplement what’s already done, read on to learn how to make a planter that will bring beauty, life and interest to your porch or patio all summer long.

I’m defining the anatomy of an outdoor planter using the age-old gardening formula: Thriller + Filler + Spiller.

You can also remember the combination as the 3T’s: Tall, Thick, Trailing. Either way, mixing and matching these plant types is sure to deliver gorgeous results.

(A)  CONTAINER

There are so many choices for outdoor planters. Whether you buy a new one, build one or repurpose a thrift store find, make sure the container has adequate space for your arrangement to mature and drainage to avoid root rot.

Lots of plastic planters — like the one below — come with plugs that need only be popped out for drainage. Use a flathead screwdriver, or similar tool, and firmly tap the top with a hammer or your hand to create drain holes. You can drill holes in the bottom of repurposed containers or planters without any.

Here’s a tip: Fill the bottom of large planters with non-biodegradable materials such as packing peanuts, pool noodles cut into pieces or plastic milk jugs that have been cleaned and dried. This way you can conserve potting mix and decrease the overall weight of the planter. Cover the filler material with weed barrier before filling with quality potting mix.

A quality potting mix will give the best foundation for your plants to thrive. I love getting the kids involved in gardening by letting them fill up containers and insert plants!

(B)  THRILLER // tall

Start with the centerpiece of the container, the thriller. These plants have upright growth, standing tall so they don’t get lost as the arrangement matures. Plants like celosia, dracaena, coral bells and angelonia add color or texture as well as a vertical element.

One of my favorite thrillers is purple fountain grass, which I’ve planted in the back of this container because I plan to place it in the corner of our patio. Thrillers can be planted in the center — if the pot will be viewed on all sides — or along the back if placed against a wall or in a corner.

(C)  FILLER // thick

Next, augment the container with fillers. These are plants with vigorous growth that “fill” the empty spaces. Look for mounding plants and flowers, such as coleus, begonias and petunias, that will provide steady color throughout the season. Arrange the filler around and/or in front of the thriller.

Persian shield and hot pink calibrachoa serve as fillers in this container. (Yes, my Persian shield has seen better days, but I pinched back the leaves and they are coming along.)

(D)  SPILLER // trailing

Lastly, add a few spillers to the edges of the container. These plants add pizzazz with their wild and carefree sprawl while softening the overall look. Trailing flowers and plants such as verbena, vinca and creeping jenny are great choices for completing an outdoor planter.

I’m using a lime green sweet potato vine as the spiller in this arrangement.

So here’s the anatomy of this planter in its final put-together glory:

Just a few more things to consider when organizing your planter:

• Group plants based on similar light and water requirements. It’s a DIY fail in the making if you mix a shade lover with a sun soaker and set them out on a hot summer day.

• Manage proportions. You can pack your container full to obtain an instant wow factor, but it may become too crowded later in the season and require replanting. (Not such a bad thing as you get to make another planter!)

• Plants may well fall into more than one thriller, filler, spiller category. Don’t overthink it. Choose plants with coordinating colors, complementary textures or even contrasting elements for a cohesively pleasing look.

One thing above all else is to have fun! Pick plants and flowers that speak to you, are pretty, and bring you joy. Then get your hands dirty and make them a part of your home. Happy gardening!  — v.

For more gardening inspiration,
please follow my Garden board on Pinterest.