By Irene Shonle, CSU Extension in Gilpin County
Three out of my many houseplants each have mild-moderate infestations of a
different insect. My lemon verbena has
spider mites, my Amazon lily has mealy bugs, and my Bay Laurel has scale. Even though I inspected them when I bought
them, it became evident in each case that the bugs were hiding in
not-very-visible nooks and crannies. And given that it wasn't that easy to find these plants, I couldn't do the sensible thing and throw them out.
While I’ve mostly kept the insect populations in check with diligent
applications of neem oil spray and the occasional shower/water spray, I have
never succeeded in eliminating them entirely. I have been so frustrated that there have been times when I have sworn to get rid of the insects even if I kill the plant doing it -- they STILL come
back! If I’m a bit negligent, the populations
explode, and I have to be careful they don’t spread to my other plants (but so far,
I’ve been able to quash any incipient populations on new plants).
Frankly, I was getting sick of it!
So, the other day, I was in the shower, and inadvertently
drowned a spider. I was astonished at
how quickly it died – I had every intention of rescuing it after I dried off,
but despite the fact that it was at the edge of the shower and that I take
quick showers (mountain wells, you know), it still was dead when I shut the
water off. Somehow, my pre-caffeine
mind made the connection between drowning spiders and drowning scales. After all, spraying with horticultural oils works by suffocation. I decided to submerge my whole Bay Laurel in water for a while to drown the scale insects. Since I was at the point of heaving the
plant anyway, it wouldn’t be a big deal if my plant didn't survive.
I got a 5 gallon bucket, taped a plastic bag around the pot
to keep the soil in, and turned in upside down in the water, submerging the
entire foliage and trunk. I left it for
24 hours, but I suspect that was overkill. Remember - I was frustrated!
Drowned scale on bay laurel -- the whitish residue is from the dead scale. |
Over the next couple of days, it became obvious that all the
scale had died. The insects scraped off
easily, or even showed signs of rot (see whitish residue on picture above).
Yippee! It’s been about a month
and a half, and I still see no signs of new scale or the tell-tale sticky honey
dew they leave behind. However, I probably should
have changed the potting soil (or submerged it as well), in case there were any
crawlers in the soil. If they come back,
that’s what I’ll do.
After the fact, I checked to see if others recommend it, and did find it
in a few places here and there, but it's surprisingly seldom mentioned, especially within Extension (for example,
horticultural oils and syringing are recommended here amongst other
methods, but not submerging: http://www.ext.colostate.edu/pubs/insect/05595.html. Obviously, this would only work for plants small enough to submerge, and succulents might not appreciate it. Otherwise, it seems like a cheap and non-toxic method to try.
Here goes my lemon verbena - next up is the Amazon lily! |
Responding to the if u can't beat em drown em theory. I have an orchid with a mealybug problem and my husband had the sane through the, we have a 75 gallon fish tank with baby sharks so he thought why not. My only concern is how long would it take a mealybugs to drown, cuz I really don't want to hurt my orchid.
ReplyDeleteResponding to the if u can't beat em drown em theory. I have an orchid with a mealybug problem and my husband had the sane through the, we have a 75 gallon fish tank with baby sharks so he thought why not. My only concern is how long would it take a mealybugs to drown, cuz I really don't want to hurt my orchid.
ReplyDeleteI have been doing this for years since I stopped using chemicals. You do not want to soak the plant for more than 24 hours. Soak both plant and soil. Buy tall trash can and fill with water for plants up to 3 feet. To soak tall fig trees find a friend with a swimming pool.
ReplyDeletethank you this is a great idea, im goin to try this on my citrus plant. hate those scales.
ReplyDeleteWith meely bugs esspecially you need to drown the roots. I used neem oil for about a month and thought they went away,then I found the berlap/mossy nest they had made in the roots. I picked as much off as possible and am now soking it in a drinking glass. Just have to wait till they all die I geuss.
ReplyDelete