0:00:02 > 0:00:04Hello, and welcome to The A-Z Of TV Gardening.
0:00:20 > 0:00:22Now, most of the plants we show you on The A To Z Of TV Gardening
0:00:22 > 0:00:27are things of beauty, for you to admire and desire.
0:00:27 > 0:00:31But not all, because our next U is for Undesirable Plants,
0:00:31 > 0:00:34those you'd normally want to avoid outright.
0:00:34 > 0:00:38Christine Walkden's found a very good place to get us started.
0:00:38 > 0:00:42Alnwick Castle in Northumberland, built in the 11th century,
0:00:42 > 0:00:47and now home to a very unusual garden.
0:00:47 > 0:00:51I'm surrounded by a rather sinister collection of plants -
0:00:51 > 0:00:53ones that you'd do well to avoid.
0:00:55 > 0:00:58Eating this can cause an agonising death,
0:00:58 > 0:01:02just a taste of this can make you vomit,
0:01:02 > 0:01:06and this plant contains one of the most toxic chemicals known to man.
0:01:06 > 0:01:09Welcome to the Poison Garden.
0:01:10 > 0:01:13This garden is so dangerous, the gates are kept locked.
0:01:13 > 0:01:16It's monitored round the clock,
0:01:16 > 0:01:20and visitors are not allowed in without a guide.
0:01:20 > 0:01:25All this is down to one woman - the 12th Duchess of Northumberland.
0:01:25 > 0:01:29She's been fascinated by poisonous plants for 15 years.
0:01:29 > 0:01:33Jane, why are you so passionate about poisonous plants?
0:01:33 > 0:01:36The same plant almost always kills and cures.
0:01:36 > 0:01:41And I saw gardens around the world, mostly which were apothecary gardens,
0:01:41 > 0:01:44and I just thought, this is a bit boring, let's try and do it differently.
0:01:44 > 0:01:48Let's focus on the kill rather than the cure.
0:01:48 > 0:01:51There are some notorious killers in here,
0:01:51 > 0:01:55such as belladonna - Italian for "beautiful woman",
0:01:55 > 0:01:57but you'll know it by another name.
0:01:57 > 0:02:01Deadly nightshade is one of the biggest nasties here,
0:02:01 > 0:02:04and if you were to eat just one leaf, it could kill you.
0:02:04 > 0:02:09But centuries ago women used it as a beauty aid, in the form of eye drops.
0:02:09 > 0:02:14This plant contains atropine, which paralyses the muscles in the eye.
0:02:14 > 0:02:18So the eye drops dilated the pupils, making them appear more attractive.
0:02:18 > 0:02:23But overuse of belladonna could cause blindness.
0:02:23 > 0:02:26Jane, which plant turns you on the most?
0:02:26 > 0:02:28The datura, without a doubt.
0:02:28 > 0:02:30Beautiful, beautiful flower,
0:02:30 > 0:02:34but every part of the plant is poisonous.
0:02:34 > 0:02:37Datura was used by the Aztecs to prepare human sacrifices.
0:02:37 > 0:02:42It would leave their victims numb to their gruesome fate.
0:02:42 > 0:02:45You have to take special precautions in this garden.
0:02:45 > 0:02:51Gloves are essential. A little while ago one of the gardeners had blisters all over their arms,
0:02:51 > 0:02:55caused by the sap of this plant, known as rue.
0:02:55 > 0:02:59Otherwise known as ruta graveolens,
0:02:59 > 0:03:03rue causes light-sensitive burns which can flare up whenever they're exposed to the sun.
0:03:03 > 0:03:08The Duchess has sourced her plants from all over the world.
0:03:08 > 0:03:11This is the castor oil plant, a native of India,
0:03:11 > 0:03:14but I used to have to take the oil of this as a kid,
0:03:14 > 0:03:17and it tasted just like poison!
0:03:17 > 0:03:21It is. It's disgusting. Revolting smell. But once you've extracted the oil,
0:03:21 > 0:03:26- you're then left with a really poisonous residue.- Right.
0:03:26 > 0:03:31You then have a really strong and very potent poison,
0:03:31 > 0:03:34and there's no antidote to that.
0:03:34 > 0:03:37The plants have really developed their strengths
0:03:37 > 0:03:41to keep away their natural enemies - insects, not really us -
0:03:41 > 0:03:45and it's how we've decided to use the plants to suit our means,
0:03:45 > 0:03:47and that's where we've had trouble.
0:03:47 > 0:03:50This is obviously a labour of love.
0:03:50 > 0:03:53I love this garden. I love the stories about poison.
0:03:53 > 0:03:57When I'm dead, I'm going to have some of my ashes scattered here,
0:03:57 > 0:03:59probably against one of the walls,
0:03:59 > 0:04:03and I plan to come back and haunt this garden and keep an eye on it!
0:04:03 > 0:04:07I'm normally at my happiest when I'm surrounded by plants,
0:04:07 > 0:04:09but this Poison Garden leaves me on edge.
0:04:09 > 0:04:13But it is absolutely fascinating.