A scourge is upon my land. A plague. A pestilence.
Perhaps I’m overstating. Let me backtrack.
Several years ago one of my gardening gurus, while perusing
my garden, commented, “Oh, you have dodder.”
I had noticed this plant (Cuscuta sp.), twining over two native black daleas (Dalea frutescens),
but was unsure of its identification. After ascertaining that it was also a
native, I just let it be. Periodically, I would pull off the vines and clean up
the daleas.
This year, I decided to be more proactive, and began pulling
off the yellow, stringy vines earlier in the process. But the strangest thing
happened. The more I pulled, the more the plant grew. Days after I spent 20
minutes pulling, the daleas were covered over again.
I looked around, and noticed small clumps of dodder in my
yard, draped over prairie fleabane (Erigeron modestus).
It was time for research. After said research, it’s become
crystal clear that I’ve made a terrible mistake letting dodder become
established.
Dodder is a parasite.
It grows from seed, shooting up a small tendril. When the
tendril encounters something to wrap around, it does so. From the website for
the University of California’s
Statewide Integrated Pest Management Program:
“Seedlings are dependent on carbohydrates stored in the seed
(cotyledons) until they attach to a suitable host. When it contacts a host, the
stem coils around the host plant and produces little structures called
haustoria that penetrate the host’s vascular tissue. The dodder plant begins to
extract nutrients and water from the host, and its connection to the soil
withers and dries.”
Sounds kind of like a horror movie, doesn’t it?
According to
Mr. Smarty Plants at the Wildflower Research Center, about 24 species of dodder live in Texas. They
produce seed prolifically, and the seeds can lay dormant in the soil for 20
years.
Also, if you remove a
tendril that has a haustoria, it remains viable for several days. It has lots
of fun names:
love vine, strangleweed,
devil's-guts, goldthread, pull-down, devil's-ringlet, hellbine, hairweed,
devil's-hair, and hailweed. Some of these names are very apt.
Dodder can only live on certain host plants, and apparently
dalea and prairie fleabane are two of those. I don’t have many daleas. I have
a whole lot of prairie fleabane.
Yesterday, I yanked up every fleabane (also some Dahlburg
daisies) with dodder and tossed them in the trash. According to UC, I missed a
step. I should have sealed them in plastic bags, so they won’t root elsewhere. (You know it's bad when you are supposed to seal it in plastic before discarding!)
Unfortunately, the daleas must go, also. Removing the host
plants is the only way to get rid of this stuff, when it is so well established.
Then I will need to replant the area with something dodder can’t use. If the
dodder seedlings can’t attach to a suitable host in 5 to 10 days, they will
die.
Then all I have to do is spend the next 20 years or so
diligently removing new plants and their hosts.
Good grief.
Favorite spot in the garden:
The zexmenia (Wedelia texana) have taken up with the narrow-leaf dayflower (Commelina erecta var. angustifolia - I think) outside my kitchen window, and it's a very serendipitous pairing. These are volunteer natives. Aren't they lovely?