TINO: The Royal Tasmanian Botanical Gardens is a beautiful place
and plays a leading role in the conservation and cultivation
of rare and threatened plant species.
The curator of the Tasmanian flora collection is Chris Lang.
So how important is it that your plants look good?
It's critically important.
We have a collection of exotics and natives here at the gardens
that are enormously precious,
and we don't want to compromise their health.
We adopt an integrated pest management approach
to the way we manage pests and diseases
that uses monitoring to determine whether any action should be taken.
If we do, I mean, there's a sort of broad sweep of approaches there,
you know, including biological, cultural, physical
and chemical control.
And chemical control is an absolute last resort.
First up, let's learn a bit about physical control.
We're standing here at the front gate, Tino,
and this really is the first line of defence.
The points of entry into the gardens,
whether it be the tradesman's entrance
or where the public manoeuvre through into the garden.
So it starts here and we really want people not to bring in any plants.
There's all sorts of pests and diseases, you know,
that could be on that posy of flowers
or, you know, whatever people are doing -
that plant that people want identified.
So, yeah, it really starts here.
So we ask that people just don't bring any plant material
into the gardens at all.
A photo is a much better option.
There's another physical control
that is undertaken frequently in the gardens.
It's a tried and true method of controlling weeds
that every gardener knows -
pulling them out by hand.
Mate, the spring flowering bulbs - they put on a magnificent display.
Yeah, it's a great display, isn't it? A real burst of colour.
It's not just plant material being carried in that poses a threat.
Sometimes the danger could be lurking on visitors' shoes.
Oh, the little heath. Yes. Yeah.
Look, this is this is one of our rare and threatened species.
It occurs only in southern Tasmania.
There's just one population and that's...that's it.
The main threatening process is a soil-borne pathogen
called Phytophthora cinnamomi, or root rot.
Now, in places like this, in Botanic Gardens,
you want to maintain them in good health
and we want to keep those soil-borne pathogens out.
And the best way of doing that, you know,
is to ensure that when people visit
that their footwear is really nice and clean.
You know, there's no adhering mud or soil.
And really importantly, you know,
that they don't step on the garden beds.
Next, cultural control.
This is all about the right plant in the right place
and adjusting care to make them less favourable to pests.
Yes, so this is the Tasmanian native section, Tino,
and this area is divided up to represent various habitat types
that are found naturally, Tasmania's flora.
Yeah.
And the cultural requirements are quite different
and vary through the length of the collection.
So this end represents rainforest species
and, you know, cool... cool/temperate rainforest species,
wet forest species.
And then down the far end, it's sort of, you know, dry forest
and coastal.
And the way we garden at this end
is sort of quite different to the other end
in terms of irrigation input and fertilising.
The right plant in the right spot is pretty fundamental, isn't it?
You certainly want to do that.
And we want to ensure that when we buy our plants,
you know, that we check them for pests and diseases
and we...you know, we're getting really good, healthy stock in.
Simple observation is one way of staying one step ahead
of destructive plant diseases.
Myrtle rust is... is a big issue in Australia.
It's been on the mainland for some time.
It's more recently made its way down here to, you know, Tasmania,
but it's having a fairly devastating impact.
Specifically targets members of the Myrtaceae family.
It's a big, big Australian family.
Your Melaleucas and Eucalypts, et cetera.
So, you know... And plants like this, Syzygium.
There are many plants that are potential hosts for this disease.
We're part of a coordinated surveillance effort,
with other botanic gardens.
It's part of the plant sort of sentinel program.
And we have a number of species here through the gardens
that we're monitoring and checking for five key pests and diseases,
including myrtle rust.
And then there's biological control.
So what's your approach here in the nursery area?
Well, Tino, as part of a balanced pest management program,
we like to attract the good guys.
And if you look down here, you know,
we've got this habitat beneath our benches.
So we've allowed these plants to grow and establish.
Hardenbergia violacea, which is in flower,
and the Stylidium, or triggerplant.
And there's some lobelia.
So, you know, there's a few species here,
but these plants attract those beneficial insects.
Things like hoverflies and lacewings and, you know.
So what's with the rose pruning?
Well, this is to provide a nesting opportunity for native bees.
So the bees just nest in the ends of the branches here.
And it provides ideal habitat for that purpose.
when the local insects aren't enough to manage pest outbreaks,
the nursery team buy in some outside help.
This is a little bottled army.
This is Persimilis. This is a predatory mite.
These are commercially available.
They're mass reared for use in commercial situations,
and even on a smaller scale in a home garden,
you could use them as well.
We've purchased these for use in our glasshouses
against two-spotted mite.
They'll kill something like seven adults in a day
or 20 immature two-spotted mites.
So they've really, really effective.
And finally, the last resort, chemical control.
Look, strictly speaking,
integrated pest management includes the use of chemicals.
Potentially. You only use them as a last resort.
They tend to be indiscriminate in terms of what they kill.
You're taking out not only the target pest,
but also beneficial organisms as well.
And you create a whole ecological niche that pests can reinvade.
And, you know, you've just got ongoing problems and issues.
There are lots of useful lessons to take away
from the integrated pest management system
used by the Royal Tasmanian Botanical Gardens.
Now, your place might not be as big as this,
but it does work on a smaller scale,
so try it out at your place.