How Can One Get Rid of Asparagus Fern?
The asparagus fern (Asparagus spp.) is grown in U.S. Department of Agriculture plant hardiness zones 9b through 11 as a potted plant and bedding plant that's popular for being low-maintenance and drought resistant. These qualities also sometimes make it hard to get rid of once it has become established in your garden, and it can become a troublesome weed if it escapes its planting spot. Thankfully, you have several chemical and mechanical options for getting rid of the asparagus fern in your landscape.
Dig It Out
If you're facing just a few isolated patches of asparagus fern, simply digging them out with a traditional garden trowel will suffice. Use the trowel to loosen the soil around the base of the asparagus fern, then grasp the plant at its base and pull it out. If uprooting is difficult, moisten the soil first with a garden hose. After removing the plant, dig up the soil where it used to be and pull out any pieces of roots or tubers left behind, as these will sometimes sprout into new asparagus fern plants.
Mow It Repeatedly
Using a string trimmer, pruning shears or similar tools, cut the asparagus fern plant down to the soil level. Doing this repeatedly can help control and get rid of asparagus ferns in several ways. First, it prevents the plant from producing berries and seeds, thus helping to halt its spread. Second, repeatedly cutting it to the ground forces the plant to expend its energy on regrowing; over time this can starve the plant's underground tubers and kill it.
Spray With Herbicide
For widespread invasions of asparagus ferns for which mowing or hand removal would pose time intensive and unpractical, consider spraying the entire patch with an herbicide. The University of Florida IFAS Extension specifically suggests an herbicide with a labeled concentration of 1 percent glyphosate. For the best results, wait to apply the herbicide until the weather forecast predicts a 48-hour dry period, as rain can wash the herbicide off of the plants before the herbicide has done its job.
Cut and Paint
For an herbicide-based eradication method that doesn't require large scale spraying, try the cut-and-paint method that works well with asparagus ferns. Using pruning shears, cut the plant down to the ground. Immediately after cutting it, apply herbicide to the cut section of the stems using a squirt bottle or a paint brush. For the best results, the herbicide should have a concentration of 8 percent triclopyr. The plant will absorb the herbicide through its cut stems, which will then kill the underground roots.
Bake It With Solarization
For widespread control of a large asparagus fern, but without the use of toxic chemicals, consider solarization. This method works best in sunny locations during the hottest weeks of the summer. Solarization kills most weeds and also sterilizes the soil to kill underground roots and any present bacteria or insect pests. Mow the entire asparagus fern patch to the ground, then spray the soil surface with water to moisten it lightly. Spread a clear, plastic tarp over the mowed asparagus ferns and weigh down the edges with bricks or rocks. The sun's rays will bake through the plastic and heat the soil to extremely high levels. After four to six weeks, the entire area will be free of weeds and soil-borne diseases or pests.
Joshua Duvauchelle is a certified personal trainer and health journalist, relationships expert and gardening specialist. His articles and advice have appeared in dozens of magazines, including exercise workouts in Shape, relationship guides for Alive and lifestyle tips for Lifehacker. In his spare time, he enjoys yoga and urban patio gardening.