Although most of us would prefer to daydream and think pleasant thoughts when hunched over and digging into the soil, it does help to be on alert when attending to gardening duties. Because, honestly, you never know when a marauding, 6-foot-tall tomato or a pushy potted plant with a baritone singing voice and a taste for blood will attack. Hey, it happens. And when it does, not even the yuckiest chemical herbicide will save you.

Below you’ll find nine of our favorite horticultural horror films — ranging from camp classics to science-fiction masterpieces to musicals featuring singing florists — where vegetation, for one reason or another, becomes violent … and we’re not just talking about vengeful Venus flytraps. Populated by plants with nefarious intentions and homicidal tendencies, watching these movies may leave you too scared to prune after dark and too paranoid to ever mess with an invasive species again. Do you have a favorite scary movie where the main villain is vegetative?

“The Thing from Another World” (1951)

Beware (and don’t bother to water): Unpleasant, vegetative creature that crash-landed a flying saucer in the Arctic Circle.

Head gardener: Howard Hawks

Potential plant food: Kenneth Tobey, Margaret Sheridan, Douglas Spencer

Nightmarish nursery talk: “An intellectual carrot. The mind boggles.”

Check out the trailer here.

“The Day of the Triffids” (1962)

Beware (and don’t bother to water): Walking asparagus shoots from outer space.

Head gardener: Steve Sekely

Potential plant food: Howard Keel, Nicole Maurey, Janette Scott

Nightmarish nursery talk: “Keep behind me. There's no sense in getting killed by a plant.”

Check out the trailer here.

“Attack of the Killer Tomatoes” (1978)

Beware (and don’t bother to water): Giant, aggressive nightshades.

Head gardener: John De Bello

Potential plant food: David Miller, George Wilson, Sharon Taylor

Nightmarish nursery talk: “We have to convince the little housewife out there that the tomato that ate the family pet is not dangerous!”

Check out the trailer here.

“Invasion of the Body Snatchers” (1978)

Beware (and don’t bother to water): Eager-to-recruit, emotionless drone people possessed by parasitic space flowers.

Head gardener: Philip Kaufman

Potential plant food: Donald Sutherland, Jeff Goldblum, Brooke Adams

Nightmarish nursery talk: “I have seen these flowers all over. They are growing like parasites on other plants. All of a sudden. Where are they coming from?”

Check out the trailer here.

“Little Shop of Horrors” (1986)

Beware (and don’t bother to water): Bloodthirsty, extraterrestrial plant with a knack for musical theater.

Head gardener: Frank Oz

Potential plant food: Rick Moranis, Ellen Greene, Steve Martin

Nightmarish nursery talk: “I'm just a mean green mother from outer space and I'm bad!”

Check out the trailer here.

“The Guardian” (1990)

Beware (and don’t bother to water): Homicidal, infant-eating tree that’s tended to by Camilla, the malevolent Druid nanny.

Head gardener: William Freidkin

Potential plant food: Dwier Brown, Carey Lowell, Jenny Seagrove

Nightmarish nursery talk: “Phil, listen …I saw something tonight. I can’t believe what I just saw. Camilla … you gotta believe me. Don’t let that woman back in your house!”

Check out the trailer here.

“Troll 2” (1990)

Beware (and don’t bother to water): Vegetarian goblins that transform their victims into plants so they can devour them.

Head gardener: Claudio Fragasso

Potential plant food: Michael Stephenson, George Hardy, Margo Prey

Nightmarish nursery talk: “They're eating her... and then they're going to eat me... Oh my Goooooooood!”

Check out the trailer here.

“The Happening” (2008)

Beware (and don’t bother to water): Deadly neurotoxin-spreading flora.

Head gardener: M. Night Shyamalan

Potential plant food: Mark Wahlberg, Zooey Deschanel, John Leguizamo

Nightmarish nursery talk: “You know plants have the ability to target specific threats. Tobacco plants when attacked by heliothis caterpillars will send out a chemical attracting wasps to kill just those caterpillars. We don't know how plants obtain these abilities, they just evolve very rapidly.”

Check out the trailer here.

“The Ruins” (2008)

Beware (and don’t bother to water): Tourist-trapping murderous Mayan vines.

Head gardener: Carter Smith

Potential plant food: Jonathan Tucker, Jena Malone, Shawn Ashmore

Nightmarish nursery talk: “They don't want us to spread it. That's why they won't let us leave. They're salting the soil to keep it contained. It's old. It has to be really old because the birds and insects and animals have learned not to land here.”

Check out the trailer here.

Which movies would you add to this list? Let us know in the comments section below.

Matt Hickman ( @mattyhick ) writes about design, architecture and the intersection between the natural world and the built environment.

9 horticultural horror films
Watch these flicks and you might think potatoes aren't the only plants with eyes.