Working on an article about catmints, Nepeta, recently it suddenly struck me: Why does Nepeta racemosa ‘Walker’s Low’ (left, click to enlarge) have such an unsuitable name? You’d never describe it as “low” growing.

Checking what I said in my own book – my big fat Encyclopedia of Perennials – I see that I gave the height as 24in/60cm. When the Chicago Botanic Garden reported on their trial of nepetas back in 2007, they gave it 30in/75cm. America’s Perennial Plant Association, when it gave ‘Walker’s Low’ its Perennial Plant Of The Year award in 2007 gave its height as 24-36in/60-90cm.

Of course it tends to flop, rather elegantly in fact, and if trussed up to keep the stems vertical would be even taller – though perhaps less appealing. But how did a plant that can reach 3ft/90cm in height come to be called “low”?

I’ve been rooting around trying to find out for the last few weeks – and have not come up with a definite answer. Can anyone help?

It’s often said to have been raised in Ireland or named for an Irish garden, but the leads turn out to be dead ends. The garden writer Jane Taylor (author of The Shady Garden, Fragrant Gardens and of the very useful Drought Tolerant Plants) has been cited as having discovered the plant – but I’ve been unable to contact her. [If anyone has contact details, please email me privately.]

Just to emphasize the fact that ‘Walker’s Low’ is not a short plant – we now have a dwarf version, reaching just 15in/38cm. It’s called Junior Walker (‘Novanepjun’) and was created by “gamma-ray mutagenesis” – tissue-cultured plants of ‘Walker’s Low’ were treated with gamma radiation, then grown on, planted out and assessed. One neat, bushy and prolific plant was chosen, give the code name ‘Novanepjun’ and the selling name of Junior Walker – acknowledging the saxophonist of that name, leader of the Tamla Motown band Junior Walker and the All Stars. It’s just starting to appear in the US, not yet in the UK.

So – does anyone have any ideas - or better still facts! - about how ‘Walker’s Low’ got its name?

* My article on nepats appeares in the May issue of the Royal Horticultural Society's magazine, The Garden.