Plums

In May we spent a weekend in Rotorua, and took the opportunity to scout out their market, held in Kuirau Park – lots of stalls with lots of vegetables and plants. There was another sale going on there too – once a month the friends of the library hold a dispersal sale of old stock from the library. Of course, I had to have a look through the books on offer.
One just amazed me – a book published in Britain and dedicated to purple-leaved plums. Now, I like purple leaved plums, but I would not have thought there was enough information to make a solid book on them.
I was tempted to buy it (I have far too many plant books!) but in the end decided it was not really a book I needed.
I thought of the book again this week as I noticed the plum trees in full blossom, including some of those purple-leaved varieties – and I still do not think I need the book!
The most common purple plum is the dark form of the cherry plum, Prunus cerasifera ‘Nigra’.
Most of us will be familiar with the cherry plum, Prunus cerasifera, as it will grow wild with the slightest encouragement. I know my childhood home had three or four large trees of the variety in its boundaries. The plums from these trees kept my family in jam for many years, and one tree – which may have been a hybrid with a Japanese plum – gave fruit big enough to be bottled.
The purple form ‘Nigra’ has small but very pretty light pink flowers at this time of the year, followed by almost black foliage. As the leaves mature through the season they lighten a little, but largely retain their depth of colour. In the summer there is a crop of small red fruit.
This tree is very useful for providing dramatically dark foliage in the garden, and will be a great contrast for lighter foliaged trees. It grows to about four metres.
‘Thundercloud’ is similar, with single pale pink flowers and deeply coloured foliage, as the name suggests.
P. cerasifera will cross with other plums, and other members of the vast Prunus genus, including the early-flowering P. mume, the Japanese Apricot.
Although there are many varieties of P. mume grown overseas, and sometimes a small selection of these can be found in New Zealand, the most popular by far of these is ‘The Geisha’. This has lovely scented flowers of claret rose, borne in mid-winter. The flowers are small, and carried among a tracery of bare branches. This tree picks well, and gardening friends have told me the flowers will scent the whole house when a generous bunch is picked.
There is a large specimen of the tree near our house, and I like to take a special walk along to look at when it is flower – it is just stunning.
One of the most popular of the flowering plums is a result of crossing P. mume and a dark coloured form of P. cerasifera – Prunus x blireiana. This has fluffy pink, fully doubled flowers at this time of the year, and as the flowers fade the coppery red leaves appear. Over the summer the leaves gradually fade to greenish bronze.
This variety gives a cheering display in the garden, and is also good for picking. It will grow to about four meters and is popular as a street tree, as it does not have many fruit.