David Larsen talks to Australian writer Margo Lanagan about Twitter and fantasy novels.

Margo Lanagan is about to have some coffee. She's written three pages of her novel-in-progress this morning, which is impressive, because in Sydney it isn't 8am yet. Shortly she will be talking to me by phone. At this moment, however, she's doing the thing people with work-from-home, writing-based lives tend to do in idle moments: hanging out on Twitter. I know this because I'm doing it too.

"There, three pages of forced labour. Was that so hard, Margo? Now, some coffee before the NZ interview. Might as well TRY to be coherent."

We exchange some pre-interview tweets. This is not your grandfather's journalism. Twitter, Lanagan comments after I shake myself loose from the website's clutches and phone her, provides water-cooler conversation for people who never used to have it.

"I suppose it hasn't made the actual writing any less solitary, but it's a very cheering thing to have on hand. I do occasionally get into that 'checking Twitter every five minutes' state - 'please, help me avoid my work'. I have a writing room for when I get completely out of control, so I can put myself out of the internet's reach."

Lanagan has well over 1000 Twitter followers. They provided a list of suggested names from which she chose the title of her latest story collection, Yellowcake. (All her story collections have colour-coded names. "I'm imagining in later life having an entire rainbow of the things".) It's interesting to speculate what it will do to the generation of young readers to have this sort of access to authors. Lanagan herself grew up in an era where writers were other-worldly figures, utterly remote from an ordinary teen's experience.

"We read a lot, we didn't have television. My mum was a librarian and she brought home a lot of interesting books, and we just read and read. I suppose I didn't really think I could be a writer myself until I was working in editing in my 20s and discovered that actually, the books that came in were not very much like published books. You had to do quite a lot of editorial work on them and it was just ordinary people who wrote them, not, you know, superstars. It didn't seem realistic until then."

Realistic is a slippery word on Lanagan's lips, because the intense realism of much of her writing - in particular her ability to evoke a teenage girl's experience of incest and rape, in her 2008 novel Tender Morsels - is grounded in her sophisticated use of the language and conventions of fantasy. Fantasy and science fiction were part of her reading diet as a child, though not an especially large part.

"I'm a very promiscuous reader. My dad's a big science fiction fan, so I'd read Dune, and Watership Down and The Lord Of The Rings." Her early short stories were "straight-down-the-line realistic, people talking and talking - God, they were boring." She abandoned the form and switched to novels, and it was only when she became badly bogged down attempting to write a fantasy novel that she returned to short fiction.

"I'd created this huge unwieldy world that I could no longer control, and I was trying to read up on speculative fiction and fantasy writers, to get some sense of how these things were done. I bought a copy of Locus magazine" - the professional journal-of-record of fantasy and science fiction publishing - "and there was an ad for the Chariot West writing course, where you spend six weeks living with other writers and work-shopping short stories."

The change of focus to short fiction came as a huge relief, and the workshop process honed her sense of her weaknesses and strengths. "I'd recommend it to anyone." The fantasy stories she wrote while at Clarion West formed the core of her first short story collection. White Time, which was published in 2000. The book was a major turning point book for her, because it got some nice reviews, after which very few people bought it.

"Up to that point I had thought of writing as something that I could direct from the outside. I'd written several books with that mindset. It was only when I wrote White Time and it wasn't particularly successful that I thought, okay, I'm never going to be successful. I might as well just write the things that seem to need to be written. Rather than trying to write towards something outside me, like a market, or some notion of who my readers were, I should just see what my imagination seemed to need to cough up."

The image of stories being coughed up in an almost involuntary way is a very Lanagan one, and she uses it a lot. "It's useful to think of the imagination as an aspect of the body, because it seems to have processes of its own that are obscure to us. You can manipulate them, but only to a certain extent. I think probably the coughing up and the vomiting metaphors first came to me when I started just throwing myself into stories, letting them have their head, letting them show me stuff, and coming in later and saying okay, now we've got this formless glob, how are we going to make a story out of this?"

The first stories she wrote this way were published in the collection Black Juice, in 2004, and this was the book that first drew her serious public attention. It won two World Fantasy awards, the Victorian Premier's award for Young Adult Fiction and was one of the American Library Association's Michael L. Printz Honour Books for Excellence in Young Adult Literature. She had not set out to write a YA book; she had deliberately avoided thinking of any specific readership. But since Black Juice came out she has been perceived, especially in America, as a YA writer first and foremost.

"Tender Morsels, which I wrote a few years after this, was slated in Australia as an adult title. I sent it off to my American publishers, who had scheduled it as a YA title, and they wrote back asking if I could make some changes. So I did."

In particular, she expanded the role of the wise witch, Miss Dance, who comes in towards the end of the story for the other characters. "My Australian editor said, 'look, this is definitely YA now, do you want it to be so explanatory?' So I pulled a lot of the new material out ... there was a lot of toing and froing, finding the right balance."

Yellowcake, out this month, required its own balancing act. Lanagan has been deluged with commissions for stories in the last few years, meaning that this is the first of her collections to be made up almost entirely of reprints, rather than stories being published for the first time.

"I was trying to get 10 different adventures that would drag you in different directions as you jumped from one to another. Because I wrote them for different places, I didn't take as much care as I usually would to avoid repetition of images or phrases from one story to the next. We placed them so they'd bounce off each other as much as possible and not echo too much."

Lanagan has faced some tough criticism from the gatekeepers of the YA world over her willingness to deal with dark subject matter in books marketed for teenagers.

On her blog, she writes, "There is a lot of pressure from anxious adult carers of children and young adults to fill children's and YA literature with explicit moral messages that can only be read one way, the 'right' way. This is not, I believe, the purpose of books and reading. Fiction is a means to make parts of the world visible in all its complexity and ambiguity, not cover up its nasty bits and hope they'll go away. Fiction (particularly fantasy fiction) provides a safe place where uncertainties can be considered and explored."

And indeed, the stories in Yellowcake do not pull their punches. One image especially, of a little boy trustingly holding a handgrenade a teenage gang member has given him while the gang watches, waiting for the grenade to explode, will be haunting my dreams for a long time to come. This is not to say that Lanagan applies no filters for teen readers.

"Some of the stories I've written in the last few years have a very dark world view, lots of unpleasant sex and people harming each other. I didn't want those ones in this book.

"They'll be collected sometime, I expect, but that book won't be part of the colour-coded series, it'll be recognisably a different artefact. Imagine some poor kid saving up his pocket money after reading White Time, expecting more of the same from me, and then finding himself reading about alien prostitutes and castration."

Margo Lanagan is a guest at the Auckland Writers & Readers Festival, Aotea Centre, May 11-15.