Is Yellow Bush Lupine Invasive on the Central Coast?
Initial Question Dec. 6, 2005:
Hi, Does anyone know of a specific location in Monterey County, or Pebble Beach where yellow bush lupine (Lupinus arboreus) is invasive?
thanks, Bruce Delgado
Erin Avery responded on Dec. 7, 2005:
We had a large dense patch within the upland side of a large wet meadow off 17 mile drive (Monterey Peninsula Country Club) that was growing every year. The maintenance crew pulled them all out and now continuously pulls out seedlings. We get the seedlings popping up throughout the 50 acre restoration site out there.
Bruce Cowan responded Dec. 11, 2005:
IS YELLOW BUSH LUPINE INVASIVE?
Yellow bush lupine (Lupinus arboreus) is definitely considered an invasive species in California's north coast where it was apparently introduced. As far as I know, however, it is native in the Asilomar/Spanish Bay area of the Monterey Peninsula. Even so, it does have weedy tendencies. It is a prolific seeder and takes over restoration projects quickly, but is often killed by aphids or natural causes after two to four years-- leaving lots of unsightly dead shrubby material and countless new seedlings.
When I worked at Asilomar 1968-1974, I planted lots of yellow bush lupines, but they proved to be very unsatisfactory for the reasons stated above. Also they were not a dependable dune stabilizer. Subsequently I have never planted yellow bush lupine since, and in most of my landscape and restoration projects I usually pulled or hoed out seedlings whenever they appeared.
I have found the silver beach lupine (Lupinus chamissonis) to be superior and adaptable to dune environments, less weedy, longer lived and visually more attractive. It is native to Monterey Bay as far south as the Naval Postgrauate School dunes. I introduced a few to Asilomar from seeds collected at NPS, and they thrived and multipled. They were about the only California native plants besides beach sagewort that did well in the dunes and weren't eaten by the deer, and they provided colorful bloom besides. I and several other people also introduced some to a few private residential landscapes in the Asilomar
area, and they were a major component of plantings at the Spanish Bay golf course. Every spring their lush purple blooms were a welcome sight.
Unknown at the time, introducing L. chamissonis even from as close as seven miles away would have a very negative impact. They were found to hybridize with the endangered Tidestrom's lupine (Lupinus tidestromii), an inconspicuous dune plant that mostly hides under the sand and, unlike L. arboreus and L. chamissonis, is actually eaten by deer when it blooms. Thus L. tidestromii is becoming extremely rare.
The hybrids form broad silvery mats covered with purple flowers, are deer resistant, and are visually superior to either parent. But because of genetic contamination to an endangered species, both L. chamissonis and all known hybrids have been or are being removed from the Asilomar/Spanish Bay area.
I don't think L. arboreus/L. tidestromii hybrids occur, so the weediness of L. arboreus must be judged, I think, on the basis of how it behaves near a golf course or any situation.
Erin Avery responded on Dec. 12, 2005:
Good information! I could see letting the seedlings stay in the restoration area, which quite frankly, has badly compacted soils or little to no topsoil, and can use all the soil conditioning it can get. But, I fear a take-over of the natural coastal prairie if the seedlings in that vicinity are left unchecked. So far, I have only seen the lupine seedlings in the dryer upland portion of meadow and not in the lower wetter areas where the typical coastal prairie species occur. I don't know if the lupines have just not been allowed the opportunity to spread that far, or if they don't like the wetter soils and would therefore not be a problem. Thanks for the good input.
Jeff Froke responded Dec. 15, 2005:
My use and success with YBL has been to plant it, watch it do well on site with limited expansion, fiercely ace-out nonnative encroachers (its best value in a restoration project), then after 4-6 years die-out leaving the site ready to plant or naturally recruit with little vegetative or seeded competition by invaders. I've used it whether it is native to the site or not, because it really doesn't matter to me in the long-run, I.e., after 4-6 years.
Bruce Cowan responded Dec. 17, 2005:
Interesting, Jeff. I have felt that, unlike non-native broom, yellow bush lupine does eventually develop a lower density in established vegetation full of Baccharis, etc. and isn't that much of a pest--ex. at Point Lobos. I didn't know, however, that it is that competitive with non-native invaders. It seems to me that ripgut grass and other weeds thrive under lupines. What kinds of plant invaders does it help control?
Jeff Froke responded Dec. 18, 2005::
I was thinking of other broadleafs like genista and thistles. I can't think of working it in areas with ripgut or wild oats for that matter, or at least where it comes in underneat the YBL. Jeff
Vern Yadon responded Dec. 19, 2005:
As we discussed the other day when you stopped by my house, yellow bush lupine isn't a very satisfactory plant for restorations. It can be quite attractive in its yellow color form when cropped by severe winds. The inland forms, however, are weedy, grow very fast. They soon build a thatch that out competes most everything else. They also hybridize with L. albifrons, L. variicolor, and probably others. My experience is that they are leggy by the second year and invariably begin to show their other color forms which leave a lot to be desired. They also attract aphis and other undesirable insects. Being native seems to be an accepted qualification for use in various restorations. All continents have some aggressive native plants that qualify as weeds. Yellow bush lupine is one of them. Another is Cardamie oligosperma, hill cress, which I grew once in a pot so it would be available for the annual wildflower show. It is much like Stellaria media, chickweed, in habit. My yard can now supply the world.
Comments
I came across this discussion while researching the status of L. arboreus from here in PA. According to Jepson, L. arboreus is "probably native Sonoma to Ventura counties, naturalized farther north". So it must be native in Monterey county and in the area of the Monterey Peninsula Country Club (mentioned at the start of this thread). And while it may turn up in restoration projects it's clearly not an invasive alien. And is the natural coastal prairie that Erin mentions not its natural habitat? Jepson notes that it is naturalized north of Sonoma county, is this not simply a result of climate change extending its range northwards?
Just looking for clarification...
Posted by: Graham Rice | March 3, 2006 04:56 AM
I consider yellow bush lupine native to Monterey County and, as such, if it
becomes dominant on a given hillside or meadow I would not remove it. My
guess is that its near-complete dominance would be temporary only, but even
if it wasn't, I wouldn't abate it because many natives such as black sage,
coyote brush, and coast live oaks, to name a few, do dominate various
locations almost to the exclusion of other plant species.
Posted by: Bruce Delgado | March 3, 2006 07:16 AM