This is 'youth' for a camellia. Camellias can easily live to 100, and far longer in the right conditions.

That was when I walked into a grassy courtyard and saw a tree, elegantly pruned to a tall, thick twisted stem, with a vast mushroom-shaped top flagrantly daubed with enormous bright red flowers, its petals a carpet among the green.

I probably stood there for half a minute, mouth open, before walking closer. This strange, magnificent creature was a camellia, but not a camellia bush. This was a camellia tree, tended for more than 100 years, so big and so majestic it didn't need to be with a hedge of other camellias, or even surrounded by flowering plants.

I planted my first camellias about 35 years ago. This has been long enough for leafy sticks to become bushes, and then small trees, though as I've never pruned off the lower branches or shaped them in any way, they will never have the glory of the cosseted one in the courtyard.

Our poor camellias have also only been pruned perhaps four times, and watered only in their first year or two. Basically I've done nothing to them beyond plant, gaze at them with admiration, and sometimes pick giant bunches of flowers for friends from the varieties that hold their flowers best when plonked in vases - though they do sometimes get the coffee grounds and tea leaves. (See below)

Camellias are survivors. After four years of drought and three months of searing bushfire winds, about half of ours were leafless, their wood dead and brittle. Branches of all of the rest had also died back to some extent. I knew I had some serious camellia pruning to do when it finally rained again.

Luckily I never got round to it. Every single camellia has come back, with both leaves and blooms, so vigorous that the new growth has pushed the dead growth off the tree entirely, or at least covered it. One more good season and there'll be no sign of what seemed to be a camellia calamity.

You can prune camellias right back, and they will survive and thrive and turn into neat hedges or explosions of blooms. Prune after flowering though - if you prune too long afterwards you may be cutting off next season's flower buds.

You can even transplant quite large ones, though they will probably sulk for two or three years and then rocket off again.

On the other hand, it is also extremely easy to kill a camellia. One over-eager bloke with a whipper-snipper can ring bark the base, and you'll only notice the damage when the camellia droops and dies. Too much fertiliser on dry soil will kill camellia roots, especially the shallower roots of younger plants.

Camellias are also prone to root rot, especially in pots where they may get not enough water, or too much water, or, just as bad, alternating too much water and dry soil.

Potted camellias are vulnerable. Your average in-ground camellia grows roots deep into the soil, where they are well protected. Cold winds, a dusting of snow, some weeks of fire's breathe - the leaves may brown and drop, but the roots will be insulated, ensuring your plant regrows.

Potted camellia roots in our climate get too hot, and too cold, and are often either fed too much at once, or not enough.

If your potted camellia's older leaves are yellowing, it needs more tucker. If all the leaves are yellowing at once, its roots may have been killed by anything from cold to too much tucker, or by poor drainage so the wet roots rot.

If your camellia is exposed on the veranda, and your hose and taps have frozen this winter, the chances are the poor potted camellia's roots have frost damage too. Brown blotches are probably sun scald. Brown leaf edges may be nutrient deficiency - give compost or a specialty camellia food. Look for scale too - if seen, spray with Pestoil to suffocate them, then use a thick round of tree banding grease on the main stem to stop ants bringing up more scale - ants harvest the sweet excretions.

It is also possible your camellia is just in the wrong place. Most camellias do best with dappled shade, even the sasanquas that are said to accept full sun.

An exposed camellia on a patio may very well be getting too much sun, or not enough sun, not to mention not enough soil to grow those long, tough roots.

If your camellia looks sickly, cut it back HARD to just a few branches. Give it a dose of used coffee grounds, which are acidic, and full of nutrients, and repel snails. If your camellia is in a small pot, or a cold spot, wrap the pot in bubble wrap or move it to a warmer spot. Better still, plant it in the largest pot you can find. Useful tip: put the pot in its eventual resting place BEFORE you fill it with soil and a camellia, or you'll need to borrow a trolley and muscles.

My camellias have given me more joy than I ever expected - and a heck of a lot more growth and blooms. In return I give them admiration, and my used tea leaves and coffee grounds as they keep growing to full camellia tree magnificence.