Visitors to the Exotic Garden regularly ask me what is my favourite plant or group of plants. This is a question that I always find difficult to answer as I love all plants and usually say the one I am looking at right now! Every year some plants in particular do really well or are new to the garden so register high on my list of favourites, but the ones that seem to catch most of my attention at the moment are the Bromeliads.

This time last year I wrote an article about this fascinating family of plants and since then my collection has grown considerable almost becoming an addiction.

Well at least they aren't deleterious to my health, only my pocket, though they often scratch my arms when moving them around as some are fairly spiky beasts! Many gardeners have or know of Billbergia nutans, an epiphytic bromeliad with greyish-green leaves native to Brazil, Uruguay, and Argentina in South America. It is surprisingly hardy as it will take a few degrees of frost quite happily if grown in a dry situation.

It does look stunning when in flower, though, with its slender pink-bracted stems which bare arching racemes of flowers with pink tubes and bright green recurved petals and spectacular purple-edges.

The down side is that for the rest of the year it tends to look more like a rather boring tussock of spiky grass.

There is a more interesting cultivar named Billbergia Santa Barbara with irregular creamy white edges with similar flowers that is well worth seeking out.

Most of the Bromeliads available in this country are grown in vast greenhouses in the Netherlands and are generally known for their intense spikes of colour, such as the Guzmanias which are green leaved with a central spike that can be bright red, yellow, pink, purple and so on. Unfortunately when not in flower they are just plain green and being truly tropical in nature are quite tricky to overwinter successfully. Because they are relatively cheap to buy they are often thrown out after flowering like cut flowers, though the flowering spike does last for several months.

Like all Bromeliads, once the inflorescence has finished (being monocarpic) the whole plant slowly dies over the following year, but as this happens small plantlets known as pups appear around the base of the parent plant. These can be removed when they are approximately one third the size of the parent and potted into a mix of roughly 50/50 mini-bark chips and general purpose compost thus simulating the sort of growing medium they would find in the wild.

A large number of Bromeliads are epiphytic, meaning that they grow on tree branches or pretty much anything they can get a hold of, hence the root system is not for taking up food but as an anchor to hold them in place.

I have been hunting for Bromeliads over the last few years which are grown primarily for their foliage rather than flowers as these give me a continuous display of colour throughout the summer months.

During the dull winter period the foliage tends to turn green but soon regain their glorious colour tones once spring returns and the suns power grows in strength.

Some of the most ridiculously coloured foliage can be found on the Neoregelias, a genus of bromeliads with mostly broad and relatively flat leaves often forming fairly wide plants. They have a shallow depression in the centre which is usually filled with water (also known as tank types) through which their fairly short flowers bloom, often under the water! As fascinating as the flowers are, it's the foliage that captivates the eye.

Through hybridisation, especially in the US, an absolutely vast array of colour combinations can be found, many looking as though they have come from some absurd alien fantasy world! There are more than 5,000 registered cultivars, hence the choice is enormous though it can be quite a challenge to get hold of interesting Neoregelias in the UK.

One of the most commonly available is Neoregelia carolinae which is green with a bright red centre or Neoregelia carolinae Tricolor which is a very jazzy yellow with green edges to the leaves with a bright red centre.

There are quite a few variations on this and a new Dutch one I purchased recently named Neoregelia Freddie has dark green leaves with paler green stripes and a brilliant red central rosette.

Vrieseas are also very attractive tank-type Bromeliads that are slowly becoming available in the UK. I have several very colourful forms like Vriesea hieroglyphica which has shiny green leaves with dark, hieroglyphic-like cross bands. Vriesea Gigantea 'Nova' is a rather stunning hybrid that has mottled foliage which has finally banded markings that change between green and light green to almost white. Vriesea Kiwi Sunset is a very desirable tightly banded maroonred form, while Vriesea fosteriana Rubra has rich, chocolate brown tones with creamy green bands. All these make excellent house plants that can be stood out for the summer months to keep them fresh.

I have decided to concentrate on collecting Billbergias as they tend to be very upright in habit taking up far less room when overwintering. There are some fabulous hybrids available and if I had to choose only one it would probably be Billbergia Domingos Martins. This highly desirable Billbergia reminds me of one of those tubeworms that are found clustering around deep sea vents at the bottom of the ocean! Mine is deep brownie-green with irregular splotches of white.

There are many crosses with Domingos Martins creating very interesting forms like Boracho, which is greyish-green heavily spotted white, and Pink Champagne which is a sort of bubbly pink! Space is short so I must tear myself away from the Bromeliads as there are so many other beautiful plants in bloom at the moment, especially the many gingerers which came through the winter unabashed by the cold and are now bursting with colour.

•This article was first published on August 27, 2011.