The Best Chemical to Kill Ficus Roots

The Ficus Strangler

• The ficus, or fig (Ficus carica), is commonly found in USDA zones 6 to 11. Invasive and opportunistic, the ficus can grow in many inconvenient locations such as through cracks in walls or small holes in drainage systems. They often overtake an entire host tree, eventually strangling the life from it. Killing a ficus is not an easy task, as they are also very quick to recover and can regrow from stumps or bits of roots that are still alive. To kill one fully, you must kill the entire root system, which usually involves chemical means.

Triclopyr Amine, Meet Triclopyr Ester

• One of the most effective ways to kill ficus roots is by drilling holes into the roots and injecting the growth inhibitor triclopyr. Two types are available on the market, amine and ester. Inject fully concentrated triclopyr amine into the roots late into the growing season. This broadleaf-selective herbicide has very low soil residuals, so has less chance of damaging future plants. Triclopyr ester works in a similar manner to amine, but is more potent and has a high soil residual, making it dangerous to other plants in the future. It has the ability to vaporize in relatively low temperatures, so should not be used when outdoor temperature is above 85 F.

Two Extremes

• Two other options for chemical treatment are glyphosate and imazapyr. Glyphosate is an aromatic amino acid inhibitor that has little soil reactivity, meaning it is not easily absorbed into the roots and must be injected into holes drilled in the roots to be effective, just as with tryiclopyr. Imazapyr, on the other hand, is extremely active in soil and its effects can last well past a year. If you plan on using the soil for a future project, it is best to avoid this particular chemical.

Getting Salty

• For the least harsh chemical effect on your soil, use copper sulfate crystals to kill ficus roots. Like other chemicals, the best practice is to excavate some large roots and drill thick holes in them. Pour copper sulfate crystals into the holes and water them well. For the resilient ficus, you may have to perform this more than once on various areas of the root system.