Gardening: Weed with royal roots

By Leigh Bramwell

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The common broom (planta genista in Latin) was the emblem of Geoffrey, head of England's royal family that died with Richard III.
The common broom (planta genista in Latin) was the emblem of Geoffrey, head of England's royal family that died with Richard III.

When you type a plant name into Google and the first six websites returned are regional councils, you know you're in trouble.

It's very unlikely you'll be told by these councils that your purchase of 100 broom plants was "inspired and why not plant a whole forest of them?".

No. They'll say: "Broom is an aggressive plant which survives at up to 1500 metres above sea level and grows almost anywhere". Naughty, naughty, naughty.

And once, when back in my neck of the woods where we spoke of broom and gorse in the same breath, I'd have agreed.

Until about a year ago, when I needed something to use as a tall backdrop to a garden of grasses and rocks. I was considering grevillea, but while I was looking for a nice one in the nursery I came across pink broom.

For whatever reason, pink broom isn't as weedy-looking as yellow broom, so I told myself they were native New Zealand brooms and took a heap home. Seeking to reassure myself with a Google search, I quickly discovered that there's more to broom than meets the eye.

Admittedly, the European version is a problem species in the cooler and wetter areas of southern Australia and New Zealand, crowding out native vegetation. But broom in general is one very interesting plant, and I'm pleased that its quirkiness will give me several excuses for growing something other people think should be annihilated.

Not that you could annihilate it even if you wanted to! Many broom types have even evolved to adapt to fire, which kills the above-ground parts of the plant, but creates conditions for regrowth from the roots and also for germination of stored seeds in the soil. It's good to know that if it ever stops raining and should our garden spontaneously combust, the broom will regenerate.

Pretty much all broom likes sunny sites and sandy soils - in fact its dense, dark green stems and very small leaves are evolutional adaptations to dry habitats. It tolerates and often even thrives in poor soils and growing conditions, which is probably why it's popular as a landscape plant for wasteland reclamation and sand dune stabilising. Two more ticks for the much-maligned plant are that it's a food source for the larvae of some butterfly species, and on the Canary Islands is widely grown as sheep fodder. So there.

People used to eat it too: the flower buds and flowers of common broom can be used as a salad ingredient (raw or pickled) and were a popular ingredient for salmagundi ("grand sallet") during the 17th and 18th centuries. However, there are now concerns about the toxicity of broom, with potential effects on the heart and problems during pregnancy. Should you be forced to defend your broom in company, you can mention that the Plantagenet kings used common broom (known as "planta genista" in Latin) as an emblem and took their name from it. Genista tinctoria (dyer's broom) provides a yellow dye and was grown commercially for this purpose in parts of Britain into the early 19th century. It was common to have a bundle of broom at weddings, but be warned by the traditional Sussex rhyme: "Sweep the house with blossomed broom in May/ sweep the head of the household away".

Pink Broom can grow to 4m high in the favourable south.
Pink Broom can grow to 4m high in the favourable south.

New Zealand broom

If you're in the parts of New Zealand where common (Scotch) broom is considered a problem and a weed, it's possible to still grow New Zealand's own native broom, Carmichaelia australis. I bought some of this on a recent shrub-buying spree without knowing it was a broom, and I'm loving it.

It grows to 3-5m and is hardy and fast growing. It's a slightly dizzy-looking thing with disorganised, willowy spines heading off in all directions, and I think its mad foliage looks great planted at the base of a group of cordylines. It is named for Captain Dugald Carmichael, a Scottish soldier and botanist who studied New Zealand plants.

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