The Mite-y Battle
All plant types are susceptible to spider mites because they are all a tasty treat. But
I truly believe that some leafy groups are more at risk. I really do. And for people that
have grown a multitude of houseplants for many years, you may be nodding your head as
you read this. For the skeptics, here are some questions to consider. Does
spider-mite-infested Croton for the umpteenth time sound familiar? How about the once
more bug-ridden Hibiscus? Still in denial? How many of you have dealt with the
continuously spider-mite-plague-ridden Ivy? Mm-hmm…I thought so.
Perhaps there are some plants that are more flavorsome to insects just like there are
some foods that are more mouth-watering to you and me. Why should it be any different
in the insect and pest world than in our own? If I had to choose between pizza and
spinach every day as my source of food, I would definitely devour the pizza. Once
the pizza ran out I’d have no choice but to start chomping away at the spinach – more
out of necessity than anything else. So maybe the Croton, Hibiscus and Ivy are the
pizzas of the pesky world. Who knows.
I don’t really care what the precise reasons are that spider mites attack and try to
devour some of my favourite plants. I only have one question:
“Don’t you just hate the little %#@&$?”
Me too.
Inspecting plants before purchasing them, looking closely at the underside of leaves and
searching in-between axils for signs of mite activity or webbing is highly recommended as
a way to avoid bringing home infested plants. Unfortunately - inevitably - some plant will
come home with unwelcome guests since it’s in contact with so many other plants. Spider
mites are a fact of life with houseplants and the only thing I’m grateful for is that
they are not the toughest to deal with, just one of the most consistent.
Photographer - Rayanne Lehman, Pennsylvania Department of Agriculture
* click for a larger format *
You can, for the most part, keep them under control and (almost) fully exterminate them when they’ve been discovered. I would be lying if I said I have never personally had a problem with spider mites considering I’ve been growing houseplants for the past twenty years. I’ve had my fair share of battles with those pesky critters and I have also used up my fair share of insecticidal soaps because of them. For the most part, the odds have been in my favour. As long as the plant was healthy to begin with – before the infestation – the spider mites have lost the battle. But the sad truth is that while they may have lost the series of battles, they had never truly lost the war.
Aside from insecticidal soaps, I tried many other things to detour and discourage them from coming back - misting, humidifiers, pebble trays, wiping and cleaning of the leaves with an occasional shower, and so on. And for awhile it helped but it wasn’t long before some plant of mine would start to show signs of them returning, especially when ideal conditions presented themselves – hot and dry. I live in an area where winters are long and cold, and summers are sometimes hot and dry, which translates to long periods of heating followed by air conditioning. That ‘hot and dry’ cocktail mixture - Sahara desert humidity levels - is a cordial invitation for spider mites to pack their bags and come on over – the whole entire clan!
A mite or two is not the end of the world but when they congregate in large numbers they
can cause serious damage. And that’s exactly what they do – gather in huge numbers. Spider
mites have a very rapid life cycle and given ideal environmental conditions, their
populations explode. Females easily lay a dozen eggs daily for weeks on end and their
troublesome offspring go from egg to adult in just a few days, leading to more eggs and
more adults and more eggs and… You can just imagine how large the spider mite population
can get in a relatively short period of time.
Photographer - Rayanne Lehman, Pennsylvania Department of Agriculture
* click for a larger format *
The damage they cause is noticeable. The leaves can appear spotted, mottled or flecked. They may also appear discolored, turn yellow, and look bleached, bronzed or scorched. It doesn’t take long before the plant is severely stressed and leaves start dropping. It’s also possible – if you don’t take care of a severe infestation in a timely fashion - your plant may die.
Mites don’t travel very far and most of them can be found on one leaf – or two and three if you’ve taken too long to eradicate them. But they can spread quickly through your plant collection by primo limousine service – the wind that blows them to other host plants and you. Yes you. They’ll hitch a ride on your clothes, hands and any dusters that come into contact with the leaf they’re already lounging on and comfortably chomping away at. They will also thumb a lift from greenhouses you visit and happily settle in your home. Before you know it, that prized Gardenia that’s been showering you with glorious flowers for years starts dropping buds prematurely and leaves along with them. You’ll wonder what’s going on at first – ‘under’ or ‘over’ watering; insufficient light or inadequate humidity – until you look a little more closely and (eek) stumble upon the silky webbing. And you know that once you start seeing webbing, it can only mean one thing - the infestation is quite advanced. Double eek!
So there you are with a frazzled plant and a few generations of spider mites. You’ll probably start by spraying the foliage from tip to soil base with a forceful stream of water to dislodge and kill as many mites as you can. You’ll almost certainly rinse the plant in your kitchen sink or shower it in the bathtub to remove the webbing, some dust and a fair amount of mites. As a further assurance, you might even spray with horticultural oil or insecticidal soap, making sure to thoroughly cover the plant, pot and top of soil, which is the only way for effective control to be achieved. You’ll repeat the process after a few days, and a few days after that, to make sure you strike any creepy crawlers you may have missed.
If you’re lucky enough, after all that rough treatment, your plant won’t be worse for wear – this time. You’ll be feeling pretty darn good about the situation just about now and you’ll breathe a big sigh of relief. You’ll even pat yourself on the back and possibly wave a fist in the air as a sign of victory and as a warning to any other spider mites that dare enter your leafy kingdom. “If you know what’s good for you”, you caution them, “you’ll pick another house to terrorize”. After all, you’ve won the battle. Until a month (or two or three) later when the spider mites are back again and you have to start all over again...
The chances of spider mites revisiting are high and you shouldn’t chastise yourself; the type
of care you provide to your houseplants and your home conditions are not always to blame.
Mites are one of the most common houseplant pests and you may find yourself dealing with
the menial task of trying to exterminate them quite often. They’ll sneak in on your clothes,
be blown in through your windows and act as a chaperone to friends and family that you’ve
invited over for a visit - except that the mites won’t settle for just a cup of coffee
(they’ll want some snacks – preferably some thick, juicy, tasty leaves). They will also
shack up through the winter on their host plants and they won’t just do it on the leaves;
they will also lie dormant – as adults or eggs – in the soil or debris until the spring
when they become active once more and start the nasty job of destroying your plants.
Photographs by: Clemson University - USDA Cooperative Extension Slide Series
* click for a larger format *
And so I dealt with spider mites for the longest time – again and again – and my croton was one plant that was constantly being washed, sprayed and battered. That plant alone went through a dozen insecticidal soaps. I won the battles but lost the war because with each return of the mites and every ensuing and tormenting treatment, it really took a toll on my plant making it weaker each time. I watched leaves burning, drying and dropping as my plant struggled to regain its health again and again after each attack. I kept isolating it and reintroducing it back into its foliage group, washing, spraying and battering its neighbours as well…just in case… I can’t say that the poor Croton was very popular amongst its peers.
At one point I considered tossing my Croton – along with other spider-mite-susceptible plants - because I was really tired of doing the spider mite eradication gig. If there were pizza-flavored plants that these pests preferred then maybe it was best to change the menu. And it really burned me up that these minute little critters might possibly win the turf war in my own home! The nerve…
“There’s got to be an easier way”, I said to self. And self responded “Oh but there is…”
And hydroculture was born.
The war has been won – by me.
“How?”, you ask
Well, I will tell you…but first…
- Imagine infestations being minimal, almost nonexistent
- Imagine even the pizza-flavoured plants being less susceptible to attacks
- Imagine being able to eradicate an infestation without harsh chemicals or sprays
- Imagine being able to reach every nook and cranny, every possible crevice so that the mites have no place to hide or escape to…no more strays…
- Imagine humidity levels being automatically improved
- Imagine being able to clear out an entire (less likely to begin with) attack with such little effort, you’ll welcome another just for the fun of being able to say “Hah! Boy did you little buggers pick the wrong house! Watch this!”
“What do you mean?”, you ask. “What does hydroculture have to do with that?”
I’ll tell you that too and I’ll use an example to do it.
I don’t really see insects of any sort anymore. Obviously there’s no more soil so soil
dwellers are part of the distant past, just a bad memory. But I don’t even see leaf
dwellers hanging around my plants all that much since I started the hydroculture
method. Now I’m not going to spin a tall tale and tell you that hydroculture is the
end-all to insect problems, just an excellent deterrent and an easier way to clean
up any possible infestations. In my case there are actually other factors
involved – the fact that I clean my plants regularly is a huge factor in my insect-less
happy world.
But aside from my over-indulgence, it doesn’t take away from the fact that if you ever have
to deal with spider mites it will be much easier with hydroculture residents than soil
dwellers. The reasons are few and simple. Spider mites cannot swim and as far as I know
they can’t breathe under water. From my understanding, they drown when dunked. And that’s
the wonderful advantage you have with hydroculture. No more harsh chemicals or cumbersome
sprays. No more repeat applications. It’s an easy process.
(first photo) Eric Coombs - Oregon Department of Agriculture;
(second photo) Whitney Cranshaw - Colorado State University;
(last two photos) John A. Weidhass - Virginia Polytechnic Institute and State University
* click for a larger format *
Disassemble the whole hydroculture set-up (plant, pot, pellets)
Fill sink (or bathtub) with tepid water (I add a squirt of dishwashing liquid)
Dunk plant and pot in water for 15 minutes (longer if you’re feeling sadistic)
Rinse clay pellets under running water (fill bucket with water and soak them
before rinsing if you want more assurance). Remove plant and pot from water and rinse carefully. Reassemble the whole kit and caboodle.
That’s it.
That's it?
Yup.
Really?
Scout's Honour
Result: Dead spider mites going down your kitchen sink’s drain. Plant free of pests.
“What do you know about this personally?”, you ask. I know that a few months ago I found a small gathering of spider mites setting up camp on my Aspidistra that I had recently added to my plant collection. This was an off-shoot that was given to me and I can’t be entirely sure if the mites had come with the plant or they’d arrived later on. I’ve wanted this plant for the longest time but Aspidistras have not been readily available at any local greenhouses for quite some time. You can imagine how thrilled I was to finally get one and how irked I was that spider mites had somehow made their way onto it. But I didn’t worry too much. I thought they were quite foolish attempting to move into my house.
I dunked, rinsed and bid the spider mites good-bye. The plant was back in its spot within a short period of time. I also rinsed its neighbour and vacuumed up the area around the plants in case any strays had decided to jump ship and try to save themselves. I never saw them again. Why let them rule? Exterminate.
I am frequently asked what motivated (encouraged) me to move into this growing method. Spider mites are one reason. There isn’t enough room in the house for both of us so one of us had to go. Hey, there’s a big world out there and they’re welcome to it, they don’t need to be in my house. And definitely not on my plants.
Now that they’ve been permanently evicted from my home there are destitute mites out there looking for room and board. The next time you open a window or answer a doorbell, be weary, it may be them trying to move in :)
* all photos above are courtesy of www.insectimages.org *
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