Heliconias spread through underground stems called rhizomes, and they do it fast. One study at the University of Hawaii found that a single heliconia plant expanded to cover nearly 13 square feet in just 18 months. Each new rhizome produces at least two lateral rhizomes in a branching pattern, meaning the number of shoots roughly doubles with each growth cycle. Left unchecked, a tidy clump quickly becomes an unruly thicket that invades neighboring beds and walkways.
The good news: you can control this spread with a combination of physical barriers, regular division, and targeted removal. Here’s how to do each one effectively.
Why Heliconias Spread So Aggressively
Understanding the growth pattern helps you choose the right strategy. Heliconias don’t spread by seed in most garden settings. Instead, they push out thick, fleshy rhizomes just below the soil surface. These rhizomes grow outward in a hexagonal pattern, sending up a new shoot at each node and then branching again. The result is exponential: a small clump planted in spring can double its footprint by the following year. Because the rhizomes travel underground, you often won’t notice the spread until new shoots pop up a foot or two beyond the original planting.
Install a Root Barrier at Planting Time
The most reliable way to stop rhizome creep is to physically block it before it starts. Root barriers made of high-density polyethylene (HDPE) are the best material for the job. HDPE is recognized across the plastics industry as the most resilient and durable option for underground use. Polypropylene is slightly harder but tends to chip or crack over time. Polystyrene is the worst choice: it crystallizes when exposed to sunlight and can begin crumbling within one to two years.
Root barrier panels come in depths of 12, 18, or 24 inches. For heliconias, go with at least 18 inches deep, since their rhizomes travel in the top 12 inches of soil and you want a margin of safety. Bury the barrier vertically in a circle or line around the planting area, leaving about one inch of the rim above ground level. That exposed lip prevents rhizomes from sneaking over the top at the soil surface. Overlap panel joints by at least 6 inches and secure them tightly so rhizomes can’t push through gaps.
If you’re planting heliconias near a walkway or property line, concrete curbing is another effective option. Unlike flimsy plastic landscape edging, which aggressive roots easily breach, a solid concrete curb blocks rhizomes and holds soil in place. It’s more expensive to install, but it doubles as a permanent hardscape feature and won’t degrade over time.
Divide Clumps Every 3 to 4 Years
Even with barriers, heliconias will eventually fill their allotted space and start pushing outward with more force. Dividing clumps on a regular cycle keeps them manageable and actually improves the health of the parent plant. Plan to divide every three to four years, doing the work in spring just as new shoots emerge. That timing gives divisions the entire growing season to establish roots.
To divide a heliconia clump, dig around the outer edge and lift a section that includes two to three mature stems along with a healthy chunk of rhizome. Cut the stems down to a few inches above the rhizome before replanting or potting the division. Use a clean, sharp blade for each cut to reduce the risk of spreading fungal infections between sections. If you don’t need more plants, compost the removed material or offer divisions to neighbors.
Remove Escaping Shoots Promptly
Routine monitoring is just as important as barriers and division. Walk the perimeter of your heliconia planting every few weeks during the growing season and look for shoots appearing outside the intended boundary. When you spot one, don’t just snap off the stem at ground level. That leaves the rhizome intact underground, and it will send up a new shoot within weeks. Instead, dig down and trace the rhizome back to its connection with the main clump, then sever it with a sharp spade. Pull out the entire escaped section of rhizome.
This kind of vigilant maintenance is especially important during the warm, rainy months when growth accelerates. Catching a runner early, when it’s only a few inches long, takes five minutes. Letting it go for a full season can mean excavating a new network of rhizomes that has already branched multiple times.
Using Herbicide for Stubborn Regrowth
If heliconias have already escaped well beyond where you want them and digging isn’t practical, a targeted herbicide can help. Glyphosate is the safest option near other plants you want to keep. It kills by disrupting a process unique to plants, is not volatile, and has little potential for absorption through the roots of nearby species. You can find products containing up to 30.8% glyphosate at garden supply stores. Paint or carefully spray it onto the foliage of the unwanted heliconia shoots, avoiding contact with anything you want to preserve.
Triclopyr amine (available to homeowners at concentrations of 0.8% to 8.8%) is another option, but it requires more caution. It should not contact the foliage or roots of desirable species nearby. The ester formulation of triclopyr is even riskier because it releases vapors that neighboring plants can absorb. Stick with the amine version if you go this route, and apply it on calm, cool days to minimize drift.
Avoid aminopyralid and imazapyr entirely in a home landscape. Both are soil-active, meaning they persist in the ground and can damage the roots of plants you want to keep. Imazapyr remains active in soil for over a year.
With any herbicide, expect to make more than one application. Heliconia rhizomes store energy underground, and a single treatment may kill the top growth without destroying the entire rhizome network. Reapply to any regrowth that appears, following the product label for timing between applications.
Combining Methods for Long-Term Control
No single technique works perfectly on its own. The most effective approach layers physical barriers with a regular maintenance schedule. Install HDPE root barriers or concrete curbing at planting time, divide clumps every three to four years in spring, and patrol for escaping shoots monthly during the growing season. If you inherit an overgrown heliconia bed from a previous owner, start with aggressive manual removal of the outer growth, install barriers along the new boundary, and use targeted glyphosate on any regrowth that appears beyond the line.
Heliconias are vigorous plants, and that vigor is part of what makes them so striking in a tropical garden. The goal isn’t to fight their nature but to give them clear boundaries and enforce those boundaries consistently.