- In this video, we are gonna talk about
one of the most deadly pests in the garden:
spider mites.
This is a pest that can absolutely decimate your garden.
It can be very hard to see and very discouraging
when you actually do get them.
I've had them on my bean crops before, my house plants,
as well as some indoor hydroponic grows.
So I'm gonna toss it up to Chris in Vancouver BC
to give you everything you need to know
to understand, prevent, and control spider mites.
- Hey, it's Chris, and if you are like me
and you are moving some plants around the house,
the greenhouse, or in the garden
and you are noticing some fine webbing along the leaves
and the stems of your plants,
then you're probably looking at signs of spider mite.
Now, unfortunately,
by the time our eyes can see this really fine webbing,
there are likely multiple generations
of this tiny arachnid all over our plants.
Now, if you're also seeing bronzing
or this weird shiny discoloration on the leaves,
then the infestation is probably already quite severe.
Spider mites are a pest
that can be found on all sorts of crops around the world,
and they can be tricky to control
if we don't understand the environmental conditions
that they like.
So, in today's video,
we are going to learn how to spot, control,
and prevent spider mites
so that they don't do any damage to your plants.
These itty-bitty pests are very small.
They are about 1/50 of an inch in size.
And, despite that really small size,
they can do really great damage due to their population
and the fact that they can reproduce quite successfully
in a short amount of time.
The average lifecycle can be less than two weeks.
So, imagine they go from colorless eggs
to the larval stage and two nymph stages,
and then moving on to the adult stage
all within two short weeks, if not less,
if the conditions are favorable.
So earlier, I was taking a look at this plant
and I noticed some fine webbing
along the stems.
So I pulled out my jeweler's loupe or my hand lens
to see if I could spot the two-spotted spider mite,
which is the more common one
that we see in our gardens,
and on our house plants and greenhouse plants.
Now, the two-spotted spider mite is usually oval in shape
and they are pale green in coloration,
and they've got these two dark spots on their side.
And because they're so small, we can't see this feature,
but they have a piercing mouth part
that goes into the plant
and sucks out the juices of the cells,
and that's how they feed.
And it's this feeding activity
that does the most damage to our plants.
Spider mites affect a wide range of plants,
including house plants, as well as garden plants,
especially raspberries, melons, cucumbers, beans, roses,
as well as fruit trees.
And one of these symptoms or clues
that we may be dealing with spider mite
is when you see this stippling
or dotted appearance on your plant's leaves.
When the stippling is quite extensive,
the plant will take on this bronzing shimmery yellow look,
and this discoloration happens
because those spider mites, remember,
they are drinking those cells dry.
And when it gets really bad,
a lot of the leaves will start to turn brown
and will likely drought.
Upon closer inspection of your bronze plant,
you may be able to spot signs of spider mite.
Now, remember, spider mites are quite small
and you probably won't be able to see them
with your naked eye,
but usually along the stems and underneath the leaves,
you may be able to spot this fine webbing,
and that's a sure sign that we're dealing with spider mite.
And if the infestation gets bad enough,
then the plant will fail and likely die.
If we've confidently identified spider mites
as being the culprit for the overall decline of your plant,
then we can start narrowing down
on the methods and the products to use
to control these little tiny arachnids.
For lighter infestations or for indoor plants,
you can try using a homemade soapy water
and rubbing alcohol solution.
So you wanna put that in a spray bottle,
spray down your leaves and the stems,
and use a cloth and really wipe down all of the surfaces
as best as you can.
Maybe even get a cotton swab
and just get into those little nooks and crannies
where the spider mites are likely hanging out.
Now, with this gentler method,
you do have to be more diligent
with trying to remove all of the different generations.
So multiple repeat applications is definitely a must.
If the soapy alcohol spray
doesn't seem to be that effective
or if the infestation is actually pretty bad
and you are set on saving that plant,
then you may need to look into chemical controls products,
such as insecticidal soap, neem oil, and horticultural oil.
Now, I would say between these products,
the oils will do a much better job
with reducing the population
because they are able to smother the eggs.
So, that will greatly reduce
the population of the next generation.
Now, I do want to mention
that these broad spectrum insecticides
have the ability to affect
more than what we are trying to target.
So we may be thinking, "Okay, spider mites on this plant,
I'm gonna spray all over."
But, if we notice here, there are some flowers,
and if pollinators come
and they come into contact with the product,
they will likely die
because we have this insecticide on this plant.
So, really, the best time to apply your product
is towards the end of the day,
and that's generally when we see a lower activity level
with the insects in our gardens.
Now, with these flowers, you wanna make sure
that you never get any product on the flowers.
Because, as I mentioned,
pollinators will be touching these parts of the plant.
Although there are some biological controls
that you can purchase,
some, like the predatory mite phytoseiulus persimilis,
is a tropical creature.
So first, I would need to create the conditions
for it to thrive and stay alive
before it can actually be effective against spider mites.
So I'm thinking there's probably a better way,
and there actually is.
So if you don't wanna go the chemical control route,
you can look into supporting green lacewings
by growing plants outside.
So, the green lacewing has very voracious larva
that can greatly reduce the outdoor populations
of spider mite.
Some plants that you can pamper throughout your garden
to add beauty and also support the green lacewing population
include ones that belong to the carrot or Apiaceae family
or the daisy or Asteraceae family,
especially those that have the small flowers
clustered more or less in a flat-top shape.
So, let's picture the fennel
or cilantro, dill that have flowered,
and also Queen Anne's lace.
And let's not forget about cosmos, echinacea, and yarrow.
So let's step back a bit
and think about how we can prevent spider mites
from entering our homes in the first place.
Now, remember, with their small size,
it's really hard for us to detect them
when we're picking up plants in the nursery or at the store.
Even if we don't find the webbing
along the undersides of the leaves,
or even if you have a jeweler's loupe,
it's sometimes really hard to tell
if spider mites are there, especially the egg stage.
So, we can never really be truly confident
that there's no spider mite on our plants,
but there are some things that we can do.
First, we can select plants
that are less susceptible to spider mites.
So if we're thinking about indoor tropicals, for example,
the finer-leaved palms
are usually more susceptible to spider mites
because they have a lot of nooks and crannies
between all of their small foliage
where they like to hang out.
So, I mean, A, it's really hard to detect them
when you're purchasing the plant
and B, once the plant is infested with spider mite,
it's actually quite difficult to clean.
Instead, you can opt for larger-leaved plants.
This way, it's easier to spot any symptoms
or signs of spider mite at the store
and not bring them home.
And B, if you do have them at home,
it's easier to clean them and wipe them
and really just keep an eye on them on a more regular basis.
So let's say you purchase this plant
and it looks wonderful as far as your eyes can tell,
what we wanna do next is isolate the plant
away from all others
whether they are going outdoors or indoors.
And this is because spider mites, because they're so small,
they are easily picked up through the wind
or brushed up onto our clothes and spread to other plants.
So we don't wanna be spreading them that way.
So I would say isolate them
for at least one lifecycle of the spider mite,
which is roughly 14 days.
And after that period, you can introduce them to your garden
or your indoor collection,
but, still, monitor for the symptoms
and signs of spider mite just in case.
This next point is key
and probably the biggest takeaway
when it comes to preventing spider mites,
and that is to understand the conditions that they thrive in
and reproduce really quickly in,
and then don't give it to them.
So the combination of dry and hot is what they like,
and this is especially true in sunrooms
and also greenhouses.
So what we can do is actually increase the humidity
around our plants,
and this can be easily and safely done through a humidifier
or a spray bottle filled with water
for your indoor collection.
And for outdoor plants,
you can use a hose on a mist or spray setting
and just spray your plants and also the surrounding areas
to really up that humidity.
If you make the space inhospitable to the spider mites,
they're not gonna wanna hang around.
- There you have it.
Everything you need to know about spider mites.
Drop in the comments the pest
that is giving you the most problems
in your garden this year.
We're gonna be doing a lot more of these guides.
But, for now, let's enjoy these incredible hollyhocks,
my first time growing in this season.
Good luck in the garden,
and keep on growing.