For God's sake, don't paint me as some kind of goody-goody, said Jeanette Fitzsimons. I assured her there was no danger of a St Jeanette piece. She was genuinely, crisply relieved. "Good."

I wouldn't dare. That "for God's sake" is an instruction disguised as a plea and I have no intention of crossing her. She is rather formidable. That is a sentence I couldn't have imagined writing before I'd met her.

This is not to say that she is not friendly. She is, but not effusively so.

She greeted us at her Coromandel farm with a grisly story about a rooster that attacked her husband Harry's granddaughter and had its neck wrung. She followed this with another tale of "life and death" on the farm, about a turkey that attacked her father who is now dead but was then 98. You can guess the fate of the turkey.

She said that if I was going to use the poultry stories, "you should say that our bull, who's massive, is so quiet we can have children in the paddock with him".

Otherwise I might come across as being anti-male animals? "Some of your readers might just read it that way." This was very droll: a perfectly done parody of what some readers might just expect of a conversation with a Green.

She agreed to an interview because she has announced she will be giving up the co-leadership of the Greens in June, but I suspect she would rather be doing other, more interesting things, like dagging sheep.

However, as we are here, she will play along, but she's no pushover. You can see why she's so adamantly opposed to a legacy as the nice lady of politics. It must have become rather tedious, and not a little insulting. I don't know how it came about.

The photographer asks if she would mind sitting outside in the sun for 10 minutes. "Five minutes," she says. She was reminding me of someone.

Later the photographer asks if she would mind sitting in a tree hut for a last picture. She says she'll have to think about that. I say "good luck getting Jeanette to do anything she doesn't want to do". She decides she will, not because our powers of persuasion have anything to do with it, but because "my grandson would be delighted if I was photographed in his tree hut".

She is, obviously, all too well aware she could look like a tree hut-hugging loony Green and that will pander to those who write rude things about her in blogs and which kind people alert her to.

Of course she no longer needs to campaign. She will see out the parliamentary term as a backbencher, then she'll leave politics, or at least parliamentary politics. I asked if she would miss the power.

She likes a joke, even some of the ones made at her expense, and she responded to that one with a startlingly witchy laugh. "Ha, ha, ha. What power?"

Well, giving her caucus a good rark-up is a sort of power. She thought that was funny too, although it wasn't exactly a joke. We've been looking at the photographs of her parents that hang on her living room wall. Were they nice? "They were lovely." Her father looks stern. "He could be stern." Like her? "I don't think I'm stern very much of the time. No, I don't think so. Do you?" While I'm thinking about this, she says, "I can give my caucus a good rark-up!"

That, I say, will come as news (although it shouldn't really) to many people. You don't survive 14 years as a party leader without being tough and being tough means having to deliver the odd rark-up. The glee with which she imparted her ability to do so was the real surprise.

The person she was reminding me of was Helen Clark. When I asked whether she liked Clark, she said: "She can be really amusing to have a conversation with. She enjoys jokes. I think... if we hadn't been in politics, we might have been friends. We both share a love of classical music and opera, we both share a love of tramping and mountains and the bush and history and literature."

And there's the rarking up, and something else they might share: they are both self-contained, rather reserved characters. You suspect they are naturally like this (it is the character of the intellectual) but that years of public life have hardened the carapace. When I ask whether she thinks she comes across as a contained person she says, "when I lose my cool and throw a wobbly, I'm usually still in charge of what I'm doing". She had a glint in her eye as she said it.

Had she ever managed to out-glare Clark who, I say, could wither a grape on a vine with a look. "I have never," she says, looking at me in a way which made me feel glad I wasn't a member of her caucus, "felt withered by Helen".

She's joked about her image: that nice, twinkly-eyed old lady (she's 65). I wondered whether she found this so amusing because it's so far from the truth. "I think it's funny because it's only a little bit of the truth and there's other bits of the truth that are important to me. You don't survive as leader of a political party all these years and having to deal with other parties and your own party and the caucus without having a bit of steel in there somewhere. Some years ago... somebody described me as a steel magnolia.

I've always rather liked that."

And that she likes this description is telling, isn't it? "Yes."

She was on the radio this week taking (mild) umbrage at being called conservative. I didn't go that far but I did wonder why she and Harry (a second marriage for both) had married. "Oh. Well. How do you answer that exactly?" Did she wear white? "No. It was an unconventional wedding." What did she wear? "I wore rainbow-hued silk." Of course she did, I say, but getting married is still conventional.

"You can call it conventional if you want to. It wasn't a very conventional wedding. But that's all right. I don't really care that much what I'm called."

She says she is still lampooned. Yoghurt-slurping? "Oh yeah, and macrame-making, sandal-wearing. I've never made macrame in my life and I notice you're wearing sandals at the moment and I'm not."

No, she had bare feet but I still couldn't imagine her making macrame or, another stereotype, overdosing on herbal cigarettes. Did she? "No, never. Boring. I've obviously had the odd cigarette when I've been out socially and it's passed around, I'll have a puff." Would she still? "Well, nobody has actually passed one around for a while. It's been more than 20 years. It's just never been an important part of my life." But it is intended as a slur. "I know. When half of the New Zealand population has smoked dope at
some stage and most of them won't now admit it. That's why it's so daft to criminalise it ..."

She gave me the decriminalisation spiel which we've all heard before, so I'll spare us, but it ended with her tsking a bit about having seen "people from time to time around Parliament ... Drunk is too strong a word but you certainly notice people who have perhaps had a tad more than they should have over dinner."

I thought she sounded a bit purse-mouthed and disapproving. "I don't disapprove unless it's impairing your effectiveness at doing your job. I mean, I drink."

She doesn't really drink. "Oh, I enjoy more than one glass in a social setting... but I've never actually drunk to get drunk. I don't like that."

I have to say she's not doing terribly well so far if she's determined to dispel that saintly image, but she does get in a few well-aimed jabs. My sandals. Jim Anderton (she was his deputy in the Alliance for five years): "Jim could have been a great leader... I learned an enormous amount from him... I learned some things about leadership that I decided I didn't want to do myself." Peter Dunne and United Future: "They were [for Clark's Labour-led coalition] going to be so much easier than us to work with. They
weren't committed to causes the way we are. They had two or three big trophies. They got Commission for the Family. I'm not quite sure what it's ever done."

She can stick a barb or two in, can't she? "Oh, yes! Absolutely." It was at this point she insisted she was not to be painted as the goody-goody "that never says ill of anybody. Because that's not me".

Still, she has the effect of making you behave rather properly. I think it's because she manages a sort of queenly decorum, even in bare feet. I certainly wasn't going to use the composting loo because it was more lampooned than her. And, I said, I wasn't about to go on about it. "Well, good," she said, "people have read about it for years. They're sick of it." I agreed heartily. What a goody-goody I am.

So much so that I'm prepared to take her word for it that she really is unconventional despite the scant proof she was able to offer. She's never owned a telly - "isn't that weird?" Not conclusively. "I do grow my own vegetables." Doesn't everyone now? "It's the new chic." Quite.

Perhaps the least conventional thing about her in the end is that she is a nice woman - not to be mistaken for a goody- goody - who has remained just that after 14 years in politics. And I'm not just saying that because I really wouldn't want to get the glare.