One thing that can be be said for Henri Rousseau whose jungly paintings dominate a new show at Tate Modern is that he would have made a terrific gardener. I can remember the late and great landscape architect Sir Geoffrey Jellicoe saying: ‘I know nothing about plants; but I do understand the spirit of plants’. Rousseau understood the spirit of plants, too, and brought them together into wonderfully dramatic compositions. Very few of the subjects of his jungle scenes are actually identifiable as particular species, or even genera, but he had a perfect grasp of how to combine foliage shapes and colours into a ‘garden’.

Were he painting them today, people would think Rousseau’s jungle settings rather trendy; here’s a miscanthus grass, perhaps; there, I think, a bamboo. This tree could be catalpa or paulownia, and behind it perhaps a koelreuteria fading to gold; those must be tree ferns, and could these be lotus flowers? Ah, there’s a mother-in-law’s tongue.

The trainspotting gardener can be kept amused for hours at this exhibition while saner people look for the engaging animals hidden among the foliage; even the pouncing tigers and lions look cuddly nature pink in gum and paw. Apparently, Rousseau never went to real jungles, but painted all his scenes from things he saw in the glasshouses of the botanical gardens of Paris. For a lesson in how to compose with plants, a trip to see ‘Le Douanier’s’ fantasy foliage can’t be bettered.

The concept of the garden centre didn’t exist in Rousseau’s day, although he would have enjoyed their variety. Some people shun garden centres, believing a plant isn’t worth having if you can get it from somewhere that puts supermarket trollies at the entrance. But, gird your loins as you battle on through the Christmas decorations and household ornaments to get to the real business. Sometimes it’s worth it.

Some weeks ago, I came away with a trayful of ridiculously cheap and beautifully grown miniature cyclamens. Now, potted on and flowering like the blazes in an unheated greenhouse, they perfume the air with gorgeous, powerful scent: heliotrope with a dusting of baby powder, contained and concentrated under the glass, although their scent is always fugitive outside.

My cyclamens never survive for long outdoors anyway, being too quickly demolished by creatures both above and below ground since I dislike chemicals in the garden. But even in the greenhouse they need protection. Vine weevils can’t resist cyclamen and, as I discovered last week that their voracious grubs had munched through the roots of some potted succulents, another trip to the garden centre has shot up the ‘to do’ list.

It is too late to water in nematodes, the organic gardener’s standby, to deal with the voracious weevil larvae; once the soil has cooled to 5×C or lower, the weevils’ pricey predators are, unfortunately, useless, but the grubs munch on regardless. I expect Bio’s Provado Vine Weevil Killer 2, which sounds gratifyingly like the Charles Bronson of the subterranean world, will do what it says on the packet.

This is also the time of year when the Country Life postbag is weighed down by catalogues of garden goodies from suppliers selling such glamorously useful (or usefully glamorous?) wares as traditional apple racks and vintage fruit crates, wirework jardinières, leather holstered secateurs and hurricane candle lamps all so beautifully photographed that even die hard urban magazine designers suddenly decide they like gardening.

I was thrilled to find that those sturdy, shallow clay pots that used to be known as alpine pans (also ideal for bulbs), are now sold by Marston & Langinger in Belgravia, which calls them classic bowls (£10 to £25 depending on size, and available by mail). These, I think, make really welcome practical gifts for gardeners. In fact, London is well supplied with shops for the greenfingered, including the rather ravishing emporium of Petersham Nurseries, en route from Richmond to Ham, and R. K. Alliston at Parsons Green both of which are stuffed to the gills with elegant pots and gizmos.

The latter company does mail order, but you can also find down-to-earth kit in the Burgon & Ball catalogue which is particularly good for knives, hoes, shears and secateurs. After all, it’s a jungle out there.

Burgon & Ball: 0114 233 8262; Marston & Langinger: 020 7881 5717; Petersham Nurseries: 020 8940 5230; R. K. Alliston: 0845 130 5577. ‘Henri Rousseau: Jungles in Paris’ is at Tate Modern, Bankside, London SE1 until February 5. www.tate.org.uk