Trick or treat: the creepiest plants for Halloween

Dead man’s fingers, corpse flower, zombie palms and of course pumpkins: here are the best creepy plants for Halloween.

Spooky: dead man’s fingers

Celebrating Halloween on October 31 wasn’t a thing when I was a child but it has become a popular excuse to dress in freaky costumes, scare the neighbours and eat lollies. The ghoulish themes hark back to the ancient Celtic festival Samhain, when the boundary blurred between the worlds of the living and dead, allowing ghosts of the dead to return to earth.

Early jack-o-lanterns were carved from turnips, potatoes and beets – the scary faces illuminated by a candle inside were to scare away evil wandering spirits. The pumpkin tradition developed in America, botanical home of the pumpkin, where they’re harvested in autumn. For us, the spring timing means pumpkins are harder to buy, although carving pumpkins are grown by north Queensland farmers. If they aren’t available, try pineapple or pawpaw. The best pumpkin varieties for carving have thin skin and soft flesh, but the flesh tends to be stringy and bland – not so great for eating. To grow your own, buy seeds online from an Australian company: ‘Jack O’Lantern’ has round, 5-7kg fruit that are tasty; ‘Big Max’ is similar while ‘Spookie’ has smaller fruit averaging 2kg. In most parts of Australia, plant pumpkins in spring and harvest in autumn.

If creepy plants appeal, dead man’s fingers (Xylaria polymorpha, pictured) is a fungus that grows on rotting tree stumps and resembles blue-black fingers reaching out of the ground. Corpse flower or titan arum (Amorphophallus titanum) is a tropical plant named for its stench of rotting flesh. When botanic gardens announce specimens are about to flower, crowds flock to witness the three-to-four-day spectacle. The flower structure can grow 10-20cm a day and reach 3m tall. Once it unfurls, it emits a powerful stink at night and heats up to attract its pollinators.

Zombie palm (Zombia antillarum) is equally fascinating and unpleasant to have around. The trunk looks like it’s been wrapped in hessian and long, vicious spines. Native to the Caribbean island of Hispaniola, the spines are said to have been used as voodoo doll needles. For something to grow at home, bat plant is a beauty. The black species (Tacca chantrieri) grows outdoors as far south as Brisbane but the larger white bat plant (T. integrifolia) is more tropical. These members of the yam family are at home on the damp, dark rainforest floor, loving high humidity, rich soil and regular moisture. The bizarre flowers resemble a bat’s face but with long whiskers; studies suggest they mimic mammals that female midges feed on.

Far easier to grow is ghost plant (Graptopetalum paraguayense), a small, rosette-shaped succulent with grey leaves tinged pink and blue. It cascades over containers or walls and needs full sun, sandy well-drained soil and minimal watering.

Q&A

After clearing weeds from my bush block I now have dozens of Gympie-Gympie plants. How do I deal with these dangerous native plants? George Rough, Mount Nebo, Qld

Said to be the most venomous plant in Australia, Dendrocnide moroides is common around Gympie and up to the Atherton Tablelands. The large shrub is covered in tiny stinging hairs that break off and inject neurotoxins into your skin, causing excruciating pain; the effects can last for months. Dead leaves are just as dangerous and airborne hairs can be inhaled. The seeds, spread by birds, often germinate in sun on disturbed soil. Dig or pull out plants by the lower stem; young leaves and stems have the most hairs. Wear a respirator, heavy gloves and coveralls; consider disposing of clothes afterwards. Try to remove seedlings when tiny.

I’ve read about a nematode, Steinernema kraussei, that treats black vine weevils. Where can I obtain them? Vanessa Nicolle, Witchcliffe, WA

Heterorhabditis bacteriophora is an even better species, available from goodbugshop.com.au. Their Nemassist range has nematodes as biological controls for the larvae of fleas, curl grubs, fungus gnats, termites, army worm and cutworms. For black vine weevil, apply in autumn or spring.

My mature Gardenia thunbergia finally produced a seed pod two years ago. Can I use this to grow plants for my children? Judy, Melbourne

The hard pods can last on the tree for years. Break it open with a hammer and sow seeds into pots of seed-raising mix in spring to mid-summer. They should germinate in four to six weeks.

Dennarque

Send your questions to: [e-mail] or Helen Young, PO Box 3098, Willoughby North, NSW 2068. The best question for October wins The City Gardener: Contemporary Urban Gardens by Richard Unsworth ($50) and Dennarque by Bill and Lata Moss ($80)