As a matter of fact I do have two kentia palms by the front door, mostly because even when they haven't been watered for weeks they are still green. They have never been fed, either. I even have a fish bone fern, though as they do need watering and more light than I give them, they usually wither after five years or so.

I never planned to grow more unusual pot plants. Indoor pot plants need work, even if it's only weekly watering. Growing plants in the ground outside is far easier. The rain will (sometimes) water them. The earth will - mostly - feed them, and if not, their roots can dig deeper looking for more nutrients. Insect, bird and other predators (mostly) control pests.

I have plenty of land outside, and even though the wombats and wallabies and possums regard my garden as ''breakfast'' it's possible - with dedication - to physically ward them off.

My first unconventional pot plant was simply an allspice tree that I bought mid-winter, then put in the sunniest spot in the living room till I could plant it after winter. To my surprise, the allspice thrived. It even tolerated my lackadaisical approach to watering. On the other hand, it didn't survive the next winter outdoors, even with a frost guard. The next one I bought remained a house plant, where I could rub the scented leaves between my fingers every time I passed.

Allspice are a massive tropical to subtropical tree. But if its roots are confined in a pot, it's not going to grow to its usual 10 metres or so. It will bonsai, especially if you pick the leaves to dry and crumble into cakes or place whole in mulled apple juice. It's a neat and glossy pot plant, and quite as lovely as a fern.

So is cinnamon, another large tree that enjoys life indoors, given enough sun and water. You won't be able to harvest the cinnamon bark that's used in cooking but the leaf buds are so intensely fragrant you may prefer them instead. Fresh spice has a depth and subtlety commercial spices lack.

Sweet potato (plant a hunk that's sprouted) makes a canny indoor plant, though don't expect to become self-sufficient in sweet potato. You may get a single root every five years if you're lucky. On the other hand, you won't get any crop at all from a fish fern.

The coffee bush has possibly been the most spectacular of our indoor garden plants. After about five years it began to grow bright red berries - coffee come from the seed inside. They are gorgeous, and after a decade or so you may even harvest enough coffee to last you a week or so from a meter-high bush and a lot more if you give it a far larger pot and let it grow bigger than mine is.

Our coffee bush goes outside every summer, not for the heat, but to control the scale. Once the scale infested it, they kept coming back. A few months outdoors gets rid of them.

Basically any plant can be grown indoors - if you are prepared to give it the conditions it needs. Most plants that survive dappled shade outdoors, like tamarillo or hellebores, will grow indoors. If the plant needs full sun you may find a sunny spot in your house is enough. Look for a sunny window, or better still, a corner with two sunny windows.

You can also buy a ''grow light'' (see your friendly garden centre) which will give you lots of exactly the right light, as a friend discovered decades ago when she queried her suddenly larger electricity bill - her son had a secret, illegal, thriving - and short-lived- plantation in his bedroom.

But if you want a few ideas to start with, try passion fruit draped up the wall then along the curtain railing to get sun, a giant pot of curly leafed mint or basil on a sunny window sill, paw paws (need much space upwards and pot wise), camellias, avocados, chili bushes, bananas, lillypillies, native limes (beware of prickles) or any of the vast range of succulents that take enormous neglect before they begin to die and even when withered may spring to life again with water.

The harvest from your pot plants will be limited only by size - the size of the pot and your ceiling - and pollination. If your plant needs the birds and bees to fruit, it either needs a holiday outdoors at flowering time, or some learned hand pollination.

Let your plants tell you what they need. Do they lean towards the window? They need more light. Give them a holiday outside. Do they lean away from the window? They're getting too much light. Are the edges turning brown? They may be sun scalded or frost bitten (pull the curtains to protect them from the cold outside the window at night) or you have yet again failed to water. Curling up with little scaly or squishy things under the leaves or new shoots? Squish pests or brush off with a toothbrush and if possible give them a holiday outside.

Most indoor plants do better with a time outside, even if you just thrust out your ferns into a deluge or misty summer evening so they can feel what genuine soaking rain is like.

You may get a valuable harvest, especially of native limes and allspice. You may find you are suddenly addicted to find out exactly how many hundred plants you can fit into a one-bedroom apartment. You may enjoy the sense of superiority when someone asks what's that? And you reply "Oh, just my vanilla orchid*. Albert and I prefer to be self-sufficient in vanilla. Do you know how many food miles are stuffed into a bottle of vanilla essence?"

You may just get the sense of wellbeing all humans feel with greenery and the generosity of the living earth around you. And that is most definitely enough.

* In the interests of full disclosure, I have never succeeded in growing vanilla indoors or out. We don't keep our house warm enough for vanilla in winter, and while we happily wear jumpers indoors, a vanilla orchid can't. But if your home is heated well in winter, you might just manage it.