Helichrysum Eradication

Snuggled into the border of the Garden for the Environment, by the corner of 7th and Lawton, a glowing mound of lemon-yellow, wooly foliage covered the ground for many years. Summer and winter, its colorful foliage provided a contrast with the Lady Banks rose arching over it, the rich purple spikes of Penstemon in season, and the deeper gold of the copper canyon daisy. Wonderful Helichrysum petiolare, or licorice plant has been a reliable performer through the years in many tough spots in San Francisco gardens. Equally happy in sun or shade, not fussy about soil and water, Licorice plant brought light colors into shady, difficult nooks. It could thrive under shrubs or in north facing garden corners. It could draw the eye to the back of the garden with its light colored foliage, creating a sense of spaciousness. It could be cut back to a little stump and it would grow anew. The horizontal, naturally tiered habit of the plant when small created a visual structure around other softer or mounding plants.

  Helichrysum petiolare at GFE.

Helichrysum petiolare at GFE.

What Happened to the Helichrysum?

Not only the patch by the 7th and Lawton corner, but also every other scrap of Helichrysum in the Garden for the Environment has vanished. The bad news is that licorice plant has been listed officially as an invasive exotic, and no matter how useful it may be in the garden, it is no longer an appropriate plant for environmentally savvy gardeners to grow.

The website of Cal-IPC, or the California Invasive Plant Council, now shows Licorice plant in an alarming red box, with big red letters that say “Invasive, Do Not Plant!…Seeds are wind dispersed, and the spreading branches will root at any point of contact with the ground. Licorice plant has been found displacing native plants in the Golden Gate National Recreation Area and other sensitive coastal areas.” 

Helichrysum joins many other plants listed as wildland weeds which were originally imported into our landscape from other bioregions, or even from other continents, often by landscapers and gardeners. Like many other tough, successful landscaping plants, Licorice plant comes from a region of South Africa with a climate very similar to ours. Fortunately, most imported species do not spread into wildlands. But while imported plants may be perfectly adapted to our climate, they are also miles away from any of their natural predators or competitors. That’s why some of them can take over in our wildlands, choking out our native plants.

Some of the most familiar and problematic invasive exotics are ice plant, broom, eucalyptus, and pampas grass. Hikers and backpackers now can see bull thistle spreading prolifically all the way up to Sierra mountain passes, displacing the fragile alpine plants in the mountain meadows and forest floors. Volunteer crews meet on weekends to weed broom and thistle out of the slopes of Mt. Tamalpais. But if you’ve ever been frustrated trying to weed a little garden, just imagine trying to weed a mountain!

Many of the late 19th and early 20th century gardeners and farmers who brought plants from other parts of the world to California were trying to do a good thing at the time. There was a time when people thought eucalyptus could be an economically important timber crop. Gardeners who loved the broom of European hillsides and moors weren’t thinking that it would be destroying fragile and unique California vegetation in the 21st century. Those people lived at a time when nature was seen as an inexhaustible reserve, which we were entitled to shape to our own desires. Draining wetlands and building dams were considered heroic feats. Now we have to work just as hard to reverse many of these experiments and protect the diversity of the natural world which we now know to be fragile and finite.

Home gardeners can play a part in the protection of wildlands by avoiding the use of landscaping plants which are listed by the Invasive Plant Council. Many responsible nurseries will not sell listed plants, but there is always a lag between the time the native plant society becomes concerned about an exotic and the time when nurseries stop selling it. In the meantime, it’s a good idea for home gardeners to check the lists themselves, and remove any garden plants which have been listed. There are always wonderful alternatives that can fill the gap in the landscape.

Back at the corner of 7th and Lawton, a variegated geranium (Pelargonium to enthusiasts) with glowing yellow foliage and striking orange flowers has replaced the Helichrysum. Nearby, dwarf Shasta daisies provide another alternative groundcover and bank stabilizer, while bringing light, bright colors into the border. Inside the garden, Heuchera maxima, our native coral bells, will replace the licorice plant in one shady spot. Another choice plant to bring light silvery foliage into a dry shady location is Plectranthus argentea ‘Silver Shield.’ And for the toughest dry shade locations, don’t forget Rubus pentalobus, Taiwan bramble, (not at all like our weedy blackberry, thank goodness) with its charming white strawberry-looking flowers and an edible fruit to follow!

  Plectranthus argentea  ‘Silver Shield.’

Plectranthus argentea ‘Silver Shield.’

While it is always sad to say goodbye to a familiar garden plant, sometimes the gardener has to play the role of grim reaper. And when that happens, it’s also an opportunity to renew the border and surprise the eye with some fun new choices. A Helichrysum eradication may just turn out to be a shasta daisy and coral bells houseparty!

  Huerchera maxima.

Huerchera maxima.