The Top 10 Best Filler Plants for Containers

A container garden is a great way to add drama to your garden and bring the beauty of live plants outside.

Designing container gardens can be intimidating with so many beautiful plants in the Garden Center. Take a tip from gardening experts and use the Thriller-Filler-Spiller formula to design your containers.

In this guide, you’ll learn how to select plants for your containers and get design inspiration.

Introducing the Thriller-Filler-Spiller Formula

When it comes to gardening with containers, you dont need to be a professional to get gorgeous planters. Follow Thriller-Filler-Spiller for the perfect recipe for a balanced, colorful arrangement.

Thriller-Filler-Spiller is a catchy rhyme that will help you choose plants for your container garden masterpieces:

• The height and texture of the thriller plants set the tone for the rest of the plants.
• Fillers do just that by adding lots of color and texture to the empty space in the middle.
• Spillers draw attention to the bottom of the container because they hang over the edge.

In the Garden Center, look for signs that show how to use the Thriller-Filler-Spiller technique.

Thriller plants add drama, height and texture, and set the stage for the fillers and spillers. Place thriller elements in the center of your container arrangement, and if it’s one-sided, place to the back.

Look for these popular Thriller plants:

• It’s tall and has a bold shape, and the pink, burgundy, and green color schemes look great. In the spring, buy caladium bulbs and put them right into potting mix in a container. Then, put impatiens, begonias, petunias, and creeping Jenny in the container. You can also buy caladium plants for your container designs.
• The cordyline or ti plant is twice as exciting because its leaves are burgundy or chartreuse and are sometimes edged in pink. The narrow-leaved cordylines are commonly called spikes. Pair cordylines with red petunias that go well with them or plants with green leaves to make a statement.
• Dipladenia and mandevilla make stunning thrillers. The glossy leaves keep things interesting all year, and the bright tropical blooms on twining stems are always a treat. Both can stand the heat and a little dryness. Mandevilla may not bloom as much in the summer, but if you water it, it will have one last burst of flowers before the first frost.
• Majesty palms make fine thrillers in tropical containers. Majesty palms need to be kept in low light, and if you don’t live in a tropical area, you should bring them inside for the winter. Aside from that, you can use conifers, small shrubs, and trees as thrillers in pots.
• Ornamental grasses are a natural thriller in containers. The moving fronds give the plant texture and interest when the wind blows. Purple fountain grass is a popular warm-weather choice. Just 15 inches tall, Little Bunny dwarf fountain grass is the right size for pots.

Filler plants pack the middle space with texture and color. If people can see your container from all sides, put Filler plants around the Thriller and keep them in the middle of the container. If you can only see one or more sides of your container, put Fillers between the Thriller and those sides.

Annual bedding plants are natural fillers and come in a range of colors that will brighten any display. And don’t forget that herbs like parsley, thyme and small rosemary plants can be tucked in as accents.

Here are some popular filler plants:

• Coleus will give your container a bright splash of color and soft leaves. Newer varieties include peach, chartreuse, burgundy and pink tones. Coleus goes well with garden grasses and bright annuals like zinnias.
• Impatiens bloom from early spring through the first hard frost. Immature impatiens are very neat plants that don’t need much deadheading. If your pot will be in full sun, check the plant tags to see which types of impatiens do best there.
• Sun-loving petunias are vigorous growers with a natural mounding habit. This bright and useful performer can fill a container or spill paint on top of it.
• Pansies and their little sister, violas, show off their bright colors all year long, even when it’s cold or hot outside. These favorites for spring and fall grow well in pots or flower beds. Their blues, purples, yellows, and reds are used to color schemes for containers.

The Spiller gives your finished planter a lush look more than the Thriller and Filler, which are the other two parts of a well-formed mixed container. This element makes even a seasonal container look like it’s been growing for years.

As spillers, most people choose perennial groundcovers that cascade down. They look great with shots of chartreuse and variegated foliage. You can expand your options with stems of petunias or other trailing flowers.

Check out these popular spiller plants:

• When you tuck creeping Jenny into the edge of a container, it leaves a wispy trail of chartreuse drops. It is sometimes called pennywort. It’s a tough perennial, thriving from zones 2 to 10. Creeping Jenny should live through the winter where you live. Cut it back in the spring for more color.
• Sweet potato vines grow from tubers and have heart-shaped, lime green leaves that like the heat. For a dramatic touch in your container, look for newer varieties that come in purple. These sweets, by the way, are not edible. Sweet potato vine can handle shade or sun. Like many annuals, it might need more water on the hottest summer days.
• When it comes to succulent pots, donkey’s tail is the classic cascading succulent. Its leaves are shaped like beans and grow in groups. Another succulent to try is String of Pearls. Add echeveria Fillers and agave or paddle succulent Thrillers to finish off your succulent container.
• Petunias are very flexible; they can fill in a display or hang over the edges. A helpful tip for making the pot: lay the petunias on their sides so the flowers hang over the edge and the soil-covered roots are facing sideways. Cover with potting mix and complete your arrangement. This gives a full, mounded look to the completed display.

Tips for Planting Containers

Whether you have a raised planter bed around your patio or a terracotta pot full of succulents, containers bring the beauty of plants close to you. This makes them easy to enjoy and easy to work with once you know a few tricks.

The first rule for a container is that it must have adequate drainage. Without a hole for water to flow through, the plants will get soggy and the roots will rot. Containers can be made of concrete, lightweight composite materials, terra cotta clay and glazed pottery.

Bigger is usually better when it comes to containers. More plants and soil can fit in a bigger container, and the container will look better. Larger containers won’t dry out as quickly, too. A problem with larger containers, though, is portability. Urns and heavy containers need to be put in place before you plant them. You can also use trolleys to move containers.

Use good-quality, moisture-retentive, well-draining potting mix in your containers. To revive used potting mix, add a slow-release fertilizer and amendments like organic compost and peat.

Maximize the impact of small containers by grouping them together. A corner filled with terra containers of many sizes will look luxurious. Use the same “Thriller-Filler-Spiller” method as before, with the tallest elements in the back or center, groups of fillers in the middle, and elements that fall off the edges.

The Best Filler Plants For Container Gardens ️