Tuesday, May 25, 2010

Stop - Don't do this! Invasives

So I'm going to help a friend work on/design her front yard.  I can be a bit controlling, so I'm letting go and said my only rule is not planting any invasives.  We all make mistakes and I've made a few, but we should really just obliterate some plants from our landscapes. 
Here is a stretch of dirt along a wall outside the MacArthur Bart Station in North Oakland.  It contains 4 of our most invasive species all rolled into one tangled mass.
In the closeup you can see cotoneaster, vinca (periwinkle), and ivy.  Not pictured is Himalayan blackberry.

Why are these so terrible?  Well cotoneaster makes big, thorny thickets and just seems to reseed all over the place thanks to the birds.  Vinca will form a huge mat, keeping any other low-growing thing or seedling from growing.  And ivy here in the East Bay tends to just blanket hillsides and swallow up shrubs and even trees.  Not only do these guys spread, but they limit the diversity of plants in that area.

Instead of cotoneaster, plant toyon, a native plant that has similar foliage color and similar berries in the late fall/winter.  Though I think the toyon berries are nicer because they are a truer red, whereas cotoneaster berries have an orangeish tint.  So toyon branches can make a nice Christmas decoration.

We actually have a native blackberry (Rubus ursinus).  Why not plant that one?  Or maybe ollalaberries, not native, but not invasive as far as I know.  As for ivy and vinca, there are tons of groundcovers to choose from that will do the same job, but not get out of control.

I'm by no means a native purist,  but I think we should all agree to at least not plant things invasive in our areas.


  1. Hear, hear! Add brooms and iceplant to the list, please! I agree with the ivy winning out, although the blackberry usually finds a way to rise above it every year.

  2. I'm definitely cheering in your corner too, and I'm not a purist either. Since moving here we've battled broom, blackberries, vinca and Algerian ivy here too. I cringe when I find vile invasive plant species for sale at my local garden center. I really think the sale of some plants should just be banned in California. I actually had no idea there even was a native blackberry, I'm going to have to look that up.

  3. Let's add pampas grass as well. Arggg.

    As for vile invasives at my garden center, I actually talked to the manager the local Summerwinds the last time I saw some broom there. First he said "people ask for it," and I said "you have an opportunity to distinguish yourself from Home Depot here". I proceeded to buy a few ferns from their nice native plant collection, and he caught up with me at my car to tell me the broom had slipped true, and he was actually committed to keeping invasives out.

    Now, admitted, it took a little, but I was quite happy that they're responsive to customer comments.

  4. Thank you so much! I especially appreciate the toyon and native blackberry suggestions. Cotoneaster is nice if you want to keep people from hiking onto your property, and have plenty of room for it to spread, but why not opt for the natives and help reclaim soil and natural habitat?

    Incidentally, I thought our state had a mandate to plant natives in public spaces. Is that no longer true? I suppose there are exceptions.

  5. My bets are on the ivy too, sorry to say. Plants that spread all over the surface are bad, but that one has those hidden runners in the ground. Pure evil. (That reminds me I need to defend the yard from the neighbor's ivy. Not my idea of what I'd like to do on a day off from work.) Coffeeberries are sort of a nice sub for cotoneaster, too, if you want berries, though black versus orangey red berries might be a hard sell. But the plants are at least closer in size to the cotoneasters that get used commonly around here in landscaping, while toyons in my experience have dreams of being redwoods.

    And for your list: please, no more feather grass!

  6. I did not mean to shortchange any of our evil, invasive species like broom, iceplant or pampas and feather grasses. They all deserve a place on the list. These were just plants along side the MacArthur Bart Station in North Oakland. I do like the idea of a post with a more comprehensive list and some alternatives. And thanks James for the coffeeberry idea. I'm starting to like them more and more.

  7. Brad, nice post.

    Algerian ivy is a major nuisance in this part of Southern California, too. If you want more information on invasive species and alternatives by area in California, here are two helpful sites:

    Good for you! And, keep spreading the word!