Hi again it's Jason from Fraser Valley Rose Farm and today I want to talk to you about the not-so-secret
weapon against spider mites and powdery mildew on your plants: sulfur. I say the
not so secret weapon because it is in fact the oldest known pesticide to humans in human history
one of the names that carried forward from that time was brimstone you may have heard of that
the Romans used it or burned it to fumigate houses against pests but it's been noted as a fungicide
an effective fungicide since the 1800s of course these days it doesn't get as much attention even
as adding eggshells to the garden so I want to remedy that in this video let's look at
the different forms and how they're used in the garden and greenhouse. The form of sulfur we're
going to talk about today is elemental sulfur that's this bright yellow stuff elemental sulfur
just means it's not combined with any other organic or inorganic compounds those are the
ones that usually kind of have a scent to them smell like rotten eggs this actually doesn't
now this form of it in the little prill here is not very convenient for application for the home
gardener so what they've done is they've ground it up into a micro fine powder that can just be
suspended into water that's this form here the dosing that you use for that is one tablespoon per
liter and as for the Americans who are following along because you don't use liters so much this is
a half gallon sprayer and about a liter is about half of this half gallon so it's a it's a quarter
of a gallon of water with one tablespoon of sulfur in it let's talk about some of the pros and cons
of sulfur powder as applied as a spray so first of all it is highly effective against powdery mildew
rusts and smuts as goes to other foliar fungus it may not be quite as effective certainly as
a preventive it may do well but it isn't going to knock down a large scale infection of black
spot as a for instance second thing to say is that it is safe compared to the alternatives if you're
talking about the chemical fungicides that you may use those can be the kind of thing that you have
to wear protective equipment for this you don't because it's relatively harmless towards animals
that is if you have pets you have kids and you're worried about what you're spraying in the garden
this is relatively safe for animals the next thing i'll say is the safety on the plants themselves
it is on on its own a very safe product to use on plants don't use it when it's extremely hot
and don't combine it with oil based products if you combine it with neem oil or horticultural
oil that will amplify the phytotoxic effects of those oils and it will cause burn on the
leaves of your plants finally when it comes to beneficial insects also fairly harmless
the again one proviso on that is it does have a special effect against mites so your spider mites
will be knocked down by that which is good news but if you're using predatory mites this would
also knock down the population of predatory mites so buyer beware on that in terms of
fungicide resistance sulfur has a good record of not developing a ton of fungicide resistance so
i certainly wouldn't start applying it every day every second every third day i would
look for times when the disease pressure is high and then use it as a knock down for powdery mildew
but in general they haven't observed much resistance towards of the fungus towards the
the application of of the sulfur next thing i'll talk about is that if you're using it as a spray
i i would like to shake it as i'm spraying just to keep it suspended i'm not sure that's exactly
necessary a little dot of soap will also help to keep it spreading on the leaves of your plants it
does leave a residue and this is something my wife doesn't like so much because she's like hey we're
trying to get rid of the look of powdery mildew when this stuff dries on the leaves it kind of
looks like powdery mildew but it is a disease so if you look closely you can tell the difference
and if it's just being applied in my case like now it's winter or into the fall i don't need
my plants to look great i just need to keep the mildew off of them as they are
closed into the greenhouse for the winter here out of the landscape you know try it out see
if you can live with the look of it but it does add a kind of a powdery or whitish uh
you know liquid residue or spray residue onto your leaves now what about the overspray what if this
sulfur doesn't land on the leaves or washes off the leaves and goes into the soil well the answer
to that is sulfur is actually a plant nutrient on its own and once it reacts in the soil it
becomes bioavailable to the plant so it's really no problem if the sulfur gets down into the soil
in fact it is used widely as a soil amendment this form here which is a little bit less pure this is
a 95 % sulfur is often used to acidify soil i made a video on how to neutralize wood ash if you add
it to your garden this is the stuff i used for that purpose and once again it breaks down into a
harmless plant nutrient don't obviously overuse it but because that would make the soil salty
and and stop the plant from being able to take up nutrients but as a overspray or as a minor soil
additive harmless entirely really quickly now i want to talk about an alternate way of applying
the sulfur and that's using it as a fumigant in a burner like this remember the ancient romans used
it almost in exactly this way and what it does is it volatilizes into the air and knocks down
all of the free spores and the spider mites it sort of covers the entire inside of the greenhouse
all in one shot certainly i think the cannabis growers use this in their grow rooms as well
you have to be a little careful because during that stage that it's been volatilized and it's
burned in the air it could be irritating to your lungs if you were in that space
so usually people will burn this at night and and then just air it out in the morning before
they go into the greenhouse i usually run it in a greenhouse like this for three or four hours
that's based on the manufacturer's instructions but you may actually have to
uh based on the size of your room vary the burning time so the other thing to say about that is it
uses a very very small amount of sulfur i mean it's just minuscule and it does not leave that
residue on the plants so it's a great way of using a small amount of sulfur to get a big effect and
you don't have to go around spraying things and you don't end up with that spray residue
but it's more for the inside of a grow room or a greenhouse like this alright i
hope that answered any of your questions about sulfur certainly if you have any questions drop
those into the comments below we can have a good conversation about it thanks again for watching