Our local Secret Garden Tour is always fascinating – eight local private gardens this year and all open in aid of the Milford Garden Club, here in Pennsylvania, which does such an impressive job beautifying our little town with flowers. And this year we found our, rather indistinct, picture in the local paper’s report of the last weekend's event – half the family is in the picture.

Well, at one of the gardens open for the tour – the smallest and definitely the most interesting – I spotted a very distinctive plant that not only had I not seen before… but which I didn’t even know it existed. It was a twisted form of the Japanese bitter orange – Poncirus trifoliata, an extremely vicious plant.

 I’ve always liked Poncirus trifoliata. It’s a member of the Citrus family but much hardier than oranges and other fruiting citrus and its unexpectedly large white spring flowers have a lovely fragrance. And the stems feature long curved, sharp and very dangerous spines. Boy, are they nasty. For its hardiness, it’s been used as a rootstock on to which oranges and grapefruits were grafted.

It actually makes fruit under its own steam, and Michael Dirr, in his Manual of Woody Landscape Plants, says: "Ripe fruits set aside for several weeks become juicy and develop a sprightly, slightly acid flavor. Serves as a substitute for lemon, pulp can be made into marmalade, and peel can be candied. After removing the numerous seeds there is not a whole lot of pulp left over." Hmmm… sounds like fun. There were a couple of unripe fruit on the plant I inspected near the gate to the garden. Doesn’t sound worth sneaking back in the dark of the night to sample.

But this was a form with twisted stems, like the plant known as Harry Lauder’s Walking Stick, the twisted hazel – Corylus avellana ‘Contorta’. In fact, that was how it was described in the handout - Harry Lauder’s Walking Stick. No, it’s far more interesting than that.

Checking around I find it has a name – Poncirus trifoliata ‘Flying Dragon’ and that this form, because it’s much slower growing than the usual one we see, is used as a dwarfing rootstock for Citrus.

OK – that’s enough about some obscure plant that it’s almost impossible to buy!