The difference between a container planting that looks finished and one that looks like it’s still waiting for something is almost always the spiller. Thrillers and fillers get most of the attention, but neither one creates density on its own. That’s what a spiller does. Spillers drape over the edges of containers making them look intentional, lush and complete.

Choosing a spiller plant well means matching it to the container’s conditions and the surrounding plants. Thriller, filler, spiller ideas are abundant. For the spiller role specifically, what matters is sideways spread and quick density—something that fills negative space fast and languidly spills over container edges without muscling out its neighbors.

Let's dig in and learn about the best spillers to improve the look of your containers.

1. Bacopa

Tiny bacopa flowers bloom in white or pale pink from spring through fall, covering the mid and lower container with fine-textured branching growth. Heat is the limitation; above 90F (32C) it tends to shut down mid-summer, then comes back once temperatures ease. Partial shade extends its season in warm climates.

It drinks a fair amount and wilts fast when dry, though it recovers. A slow-release fertilizer from Amazon worked into the mix at planting keeps it going longer without much ongoing effort. Pretty white bacopa plants can be found at the Home Depot.

2. Sweet Potato Vine

Hot climates need a spiller that isn’t bothered by heat, and sweet potato vine can be the answer for USDA zones 9 and up. Dense, fast-spreading foliage in chartreuse, deep burgundy, or near-black—the color holds through summer heat when a lot of other plants start looking sorry for themselves. It wants full sun to partial shade and drinks quite quickly in containers. Trim it occasionally or it’ll try to take over. Find a 6-pack of black sweet potato vines from the Home Depot.

3. Creeping Jenny

Few low-growing spillers are reliably hardy into very cold zones. Creeping jenny is hardy down to zone 3, which opens it up for climates where the spiller options get thin. The golden-yellow form brings a brightness that stands out even in lower light—it spreads fast and stays low, rooting as it goes.

Partial shade and consistently moist soil are what it wants. In cooler zones it often overwinters in the container rather than needing annual replacement, which many annuals can’t manage. Find creeping Jenny plants at Garden Goods Direct (and they are on sale for Memorial Day!)

4. Calibrachoa

Calibrachoa looks like a miniature petunia but skips the maintenance—no deadheading, and it blooms more consistently. It mounds slightly and trails at the rim, so it handles the mid-level while softening the container edge at the same time.

Heavier feeder than most spillers; it needs full sun and good drainage to perform. Iron deficiency shows up as yellowing between the veins and is fairly common in high-pH containers—a chelated iron supplement from Amazon sorts it out once the symptoms appear. A pretty purple calibrachoa from Proven Winners can be found at the Home Depot.

5. Sweet Alyssum

Zone 5 through 11 covers a lot of ground, and sweet alyssum is one of the few spillers that’s genuinely useful across that range depending on when it’s planted relative to the season. It stays low—roughly four to six inches (10–15cm)—and fills the lower sections of a container with dense clusters of tiny white, pink, or purple flowers with a faint honey scent.

In the hottest weeks it can look tired and paused; shearing it back by about half usually brings it back within a couple of weeks, which is a better return than replacing it. Find a 6-pack of sweet alyssum plants from Lowe's and get ready to attract tons of pollinators!