Yesterday started with a frost but the sun soon saw that off and it was a lovely day. Today is overcast and theoretically milder but with no sun and a brisk, though not cruel, east wind it feels much colder. Yesterday we got lots of gardening done and, as a result, I need to take it easy today. Having ‘done in’ my back lifting paving a few weeks ago I have been seeing a chiropractor twice a week since and tomorrow is the last session (for a while) so I need to be a bit sensible. Lots is happening in the garden but I am going to feature a few of my houseplants. I have neglected any mention of them for what seems like years, so it is time, if not timely, with all the colour in the garden, to mention a few.

We will start with Pachira aquatica, sometimes called the Malabar chestnut. I first knew this large, tropical tree when at Kew when I worked in the Palm House. I would climb the spiral staircase to the upper walkway and gaze at the amazing ‘fibre-optic’ flowers. Each comprised five thick, creamy petals, often said to resemble a peeled banana, and a central cluster of long, creamy, orange-tipped stamens. Morning work always started with clearing up fallen leaves from the cast iron gratings and many of these were from this huge tree. It is curious that, almost half a century later, I am doing exactly the same thing!

While pachira was a plant only seen in botanic gardens then, it is now one of the most common houseplants. Like many people, I got (and have bought in the past) mine from IKEA. The large flowers, said to be among the largest of all tree flowers, beaten only, perhaps, by magnollias, give rise, after being pollinated by bats, to large fruits that contain up to 25 large seeds. These are sown and four or five seedlings are plaited and planted to produce the plants we are so familiar with. Most are plaited and cut off at about 1m high. They then sprout and a relatively inexpensive ‘large’ houseplant is produced.

Pachira is in the Malvaceae (or Bombaceae if you prefer), the family that gives us hibiscus, hollyhocks and chocolate (Theobroma – possibly in Sterculiaceae – Malvaceae seems to be in a state of flux). It is native to South America but is grown in many tropical countries where the seeds, which are said to taste like peanuts, are eaten. It is a medium-sized tree that grows in wet soils and has palmate leaves, rather like a a horse chestnut (aesculus).

As a houseplant it is bold and relatively easy to look after. It requires good light but not direct sunlight, which will scorch the leaves. It is often said that it needs little water but I do water mine liberally and it is fed at least once a week – I tend to feed continually with a small amount of fertiliser in every can for most of my houseplants. It needs a winter minimum of 10c and then the soil should be kept a bit drier. I do not mist this plant but I do mist other plants in the conservatory daily and there are lots of plants around it.

There are two ‘annoying’ features of the plant.

Firstly, it grows very fast. It tends to grow in spurts, producing growths that can be 1m in length. Then the shoots stop for a while to mature before more growth is produced. For this reason I periodically prune out one or two of the tallest shoots so there is always new and old growth. You could prune back all the young shoots in one go if you prefer. If in a shady spot the new growth will be very thin and likely to lean but you can always prune these back half way.

Secondly, it is always dropping a few leaves and every now and then it decides to have a proper leaf-drop. This is normal and many tropical plants do this.

When it comes to pests, red spider mite can be an issue though, at present, mine is OK. Mealy bug and scale can also be troublesome. I am battling with mealy bug having introduced it in a stag’s horn fern I bought. I wipe off what I see on the pachira but it is not too bad. I have had my plant three years and it is probably 4m high.

Overall, this is a good houseplant. I have seen very small plants with plaited stems just 20cm high. I don’t think these would be very successful in the long term because they are sold as ‘desk’ plants and when you consider the potential height of the new growth it would be tricky to keep them at a sensible height. Of course, few houseplants are sold with the intention that they should live!

I don’t know why, but everything I write about seems to lead to confusion and it seems that the pachira grown as a houseplant is not P. aquatica but P. glabra. The difference will be obvious when the plant flowers – P. glabra has pure white flowers, but that is not going to happen in the average home. Pachira glabra stems also become swollen at the base when young unlike P. aquatica so it is likely that the houseplants sold are strictly P. glabra. But like so many things, it is probably best to plead ignorance and stick with P. aquatica and not rock the boat.

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