There are over 100 different varieties
of poison plants here in the poison garden.
Before visitors are allowed to enter they must have a safety briefing.
Many of the plants in here do grow wild in the UK
and most of the plants are alarmingly easy to cultivate.
The most deadly plant at Alnwick will be things like monkshood
or wolf's bane, both types of Aconitum.
Probably the most poisonous plant we actually have here is ricin,
better known as the castor bean or castor oil.
The Guinness Book of World Records considers
that to be the world's most poisonous plant.
Really, really surprising
on how many flowers that are just normally in anybody's garden.
I never knew that they could have the reaction that they could give you.
This one will be a great example. This is the laburnum tree.
This is the second most poisonous tree in the UK.
Many people have these in the garden because of
the beautiful blossom that appears in the late spring, early summer.
They contain a poison called cytisine. The tree is so poisonous
that if one of the branches was to fall to the floor,
lay there for several months and the dog later comes along,
picks it up to hold as a stick on a walk,
the chances are the dog won't finish the walk, it's that poisonous.
Plants that grow out in public spaces, will be things like rhododendrons.
They contain a poison in the leaves called grayanotoxin,
which will attack your central nervous system.
You're not likely to eat the leaves, though, because they taste disgusting.
But if a number of the plants grow together, they poison the soil
at the base of the plant so nothing else will grow but rhododendron.
This is how they can spread so easily and cover vast areas.
If bees make honey exclusively from the flowers of rhododendron,
the honey becomes unusual in its appearance.
It's got a red tinge to it.
Small doses can give you hallucinogenic effects,
larger doses would be fatal.
This is the one plant in here that you don't need to eat, touch or smell,
but it still has the potential to kill you.
The whole of the bush is poisonous. In those leaves,
there are two chemical compounds that by themselves are harmless,
but when you mix them together, they produce cyanide gas.
It's the plant's natural defense against browsing animals.
The chewing motion, of course, releases the gas,
so when you cut this with hedge cutters, that also releases the gas.
Normally you're in this outside well-ventilated space
and on a windy day, it's probably not going to be an issue
until you put the cuttings into the boot of your car to take to the tip.
You're now in a confined space, poor ventilation and cyanide gas.
Hellebores. Hellebores are very common in many people's gardens.
Arguably the most famous would be the Christmas Rose. In the root
there's a cardio toxin called helleborine
which will slow down and stop your heart.
In the sap, there's a very strong skin irritant,
So you should always wear gloves when you're gardening with hellebores.
And here's a little tip, don't remove your gloves like this.
We have to take a lot of precautions
when we're working with the plants in the Poison Garden,
some of the beds, you don't have to take any precautions at all,
whereas you'll get to like the giant hogweed bed
and then you have a full hazmat suit on, facemask, gloves.
I don't think it concerns me because I feel like we're in their spaces.
A lot of these plants, I think, might have been there before we came along.
So it's up to us to learn and educate ourselves about all of their uses,
because a lot of the plants in here are used for good. They're not all bad.
A number of plants that bring cures
for diseases such as the yew tree, which is the most poisonous tree in the UK,
produces a poison called taxine,
which is capable of killing you in about 20 minutes,
but also produces a medicine called taxol,
which is used for the treatment of breast cancer.
Meadowsweet and the willow tree
are containing a substance called salicylic acid,
it's nature's version of aspirin.
Small doses are beneficial for pain relief.
Larger doses will thin your blood and cause you to bleed internally.
Vinca Major, also known as periwinkle.
It produces beautiful blue flowers that appear in the wedding poem:
'Something old, something new, something borrowed,
something blue.' They used to make a garter from the flowers
and present it to a bride on her wedding day.
Back then, they thought it would enhance the bride's fertility.
In reality, if you eat this, it will dramatically lower
your blood pressure, cause heart arrhythmia,
and stop the production of white blood cells, so it will kill you.
But on the other hand, if you suffer from leukemia, it can produce
one of four medicines which may save your life:
Vinblastine, vincristine, vinorelbine, vindesine.
All come from periwinkle.
I started working in the drugs field about 23 years ago,
and I started off working on a drug rehab unit in HMP Northumberland.
The northeast of England
has the highest rates of drug deaths in England and Wales.
Something needs to be done in terms
of actually getting information to young people out there.
So the drugs education programme stems from the poison garden tours
where we do have drug plants, and the whole idea behind it
is to prevent drug related harm.
We have the ABC of drugs. We grow opium poppies,
which can be used to make a class A drug, which is heroin.
We have cannabis, which is a class B drug, and
we also have catha edulis, commonly known as 'khat' which is class C.
We do have to be really, really strict with
with the cannabis and the catha edulis as well.
So I actually have a Home Office licence to grow cannabis at the Alnwick Garden,
but I have to count how many seeds I plant, count how many germinate.
We have to take photographs of planning them,
take photographs of digging them out
and photographs of destroying them at the end of the season.
And then all of that has to be filed and sent to the Home Office once a year.
So I'm sure there's much more to be discovered from poisonous plants,
who knows, it may find the next miracle cure
for whichever disease appears on the horizon next.