Southern belle: Freesias need a lot of help outside of their native South African home

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The Independent Online

I've just finished repotting freesias. It's taken a long while to be able to write that sentence. When I first started to grow them, I didn't have a greenhouse and the corms had to stagger through winter (which is when they are actively growing) in the cold frame. They put up with it – just – but did not thrive and increase. Now that they've been given slightly better conditions, they show more interest in life.

South Africa is their home, and, as with other southern hemisphere plants, their clocks are set to grow in what for us is the wrong season. But if you can keep them through winter at a temperature around 10C (50F) they won't notice they are in the wrong country. Our freesias aren't as warm as that. The greenhouse is kept just frost-free. But their performance this past spring made repotting a worthwhile exercise. Now is the latest time you can plant or repot for a display in early spring.

With us, they flower at the same time as the slightly tender rhododendron, R. fragrantissimum and the smell is overwhelmingly wonderful: rich, sweet, powerful. And pervasive, with a hint of ripe plum lingering in the sweetness. The smell is always strongest in the white and yellow flowers. The pinks, purples, oranges and reds that breeders began to produce from the 1890s onwards remain stubbornly without smell. The scent gene in a flower is often associated with some other trait (frequently colour) and as that disappears, so does the smell.

The corms are the size and shape of acorns and it's easy to see which way up they should go. Plant no more than 2cm (1in) deep. Six corms will fit in a 13cm (5in) pot or 10 in a 15cm (6in) pot. Old gardeners recommended a compost made up from three parts loam, one part peat, one part half crumbled cow manure and half sand. I pot ours in a standard mix of two parts John Innes No 3 loam and one part 6mm grit. I don't hear them begging for the cow manure, but they do have a sprinkling of Osmacote slow release granules before the pots are topped with a layer of 6mm grit. It looks good and keeps shoots clean when they first push through.

Water the pots and stand them out of direct sun in a greenhouse or cold frame. They like to grow in a coolish environment, though not a cold one. You could keep pots outside on a terrace, provided you have a cloche standing by to protect them on cold nights. But a greenhouse provides much better growing conditions, as I've discovered.

Once you've watered them, you've little to do but wait. The leaves come through first, flat and sword-shaped like an iris, but a brighter green. Then, if you are lucky, you'll get enough flower stems to make it worth the effort of carrying the pot indoors to a windowsill that's not too hot. The flowers last an incredibly long time. Florists know that, which is why freesias are such popular cut flowers. But uncut ones are even better. The stems are strong and wiry, but the plants need support. A few twiggy sticks pushed into the pot, before they are needed, is usually enough to prop up the flowers.

When they have finished, allow the growth to die down naturally. In early May, I took the pots out of our greenhouse and they've been standing outside all summer, taking whatever weather has been thrown at them. The grit in the mix keeps the compost well drained. They need that, or they'd rot.

When gardeners were more interested in growing freesias, they used to be able to get named varieties, such as the fabulous 'White Swan'. Now you are mostly offered mixtures, singles or doubles. The yellows seem to grow more strongly than the other colours.

Like freesias, lachenalias come from the Cape and tick to that same southern hemisphere clock. You need to plant them now to flower by next April and they also need the protection of a greenhouse or cold frame to get them safely through winter. In South Africa, they're called Cape cowslips, but the species I grew (L. pustulata) didn't look anything like our native cowslip.

The first thing to appear are two weird leaves which come through quite soon after planting: stiff, thick, fleshy things, covered on the upper surface with bumpy little lumps like frogspawn. Between them rises the flower stem, very stout and covered in a soft greyish bloom. The sweetly scented bell flowers (there may be up to 20 of them) are held in a spike 9cm (4in) long and come out alternately around the stem, each supported by a strange, jutting little bracket. They are beautifully marked, the ground colour white with a hint of pale blue which becomes deeper at the base of the flower. The top two petals fold back to display the knobby little stamens and style, which jut out precociously. The lower petal curls down and away from the centre. Each one is tipped with a purple line.

Perhaps the closest thing we have got to this in Europe is the Spanish bluebell, but the lachenalia, named after Werner de Lachenal, an 18th-century professor of botany at Basel university, is very much more complex and interesting. You need to grow them in pots, for they are not hardy, but in a cool environment (10C/50F) the flowers last a long time (more than six weeks) so a potful of bulbs makes a good display. Use two parts of a loam-based compost (John Innes No 3) mixed with one part 6mm grit and water only moderately until growth starts. Reduce watering as the foliage fades and keep the bulbs dry until fresh growth starts again the following season. Feed every two weeks while the plants are in active growth. Six bulbs should fit comfortably into a pot 15-25cm across. Plant them 5cm deep, 3-5cm apart. They build up into pleasingly robust clumps.