This is a row of two year old seedlings of Morton citrange, growing outside but with some protection from the side of my winter heated greenhouse.
It can still get very cold here, as the picture taken in January 2001, confirms!
About 100 years ago, the first controlled crosses were made between the hardy Japanese Bitter Orange, Poncirus Trifoliata, and the Sweet Orange, Citrus Sinensis. These are sometimes known as Citroncirus, but more popularly as Citrange. There are now many named varieties, often grown as rootstocks for commercial citrus varieties. The Poncirus parentage invariably results in some degree of cold hardiness but also some bitterness in the fruit. The promise of delicious, cold-hardy citrus has not been realised, but these plants survive considerable frost and should be more widely known. I have yet to discover a fruiting Citrange growing in Britain. Does anyone out there know of one??
Unfortunately, I haven't yet produced any fruiting citrange plants, so I have scanned some prints from 'Yearbook of the Department of Agriculture' from 1904 to 1906. These books contain articles about "New Citrus Creations" by H. Webber & W. Swingle, describing the very first Citranges.
Click here to view these Historic Citranges pictures.
Hardy to about -10C
page updated 5th October 2005
Leaves of sweet orange, citrange and Poncirus trifoliata. The citrange leaf is very clearly a half-way-house between the other two.
I obtained budwood in 2001, and budded on to Poncirus trifoliata. The plant grew well and I planted it outside in spring 2004, somewhat protected by a fence and concrete posts. However, it seemed to be lacking nutrients and, as you can see in the second photo the leaves turned very yellow.
The last photo, in October2005, shows some improvement but still very little overall growth.
Hardy to about -12C?
Poncirus trifoliata x Citrus sinensis
(C. paradisi " Duncan" x Poncirus trifoliata) x C. sinensis "Succory"
One of the Morton citrange plants, now about 1m30 (4ft) tall, growing outside in October 2005.
Carizzo citranges in Georgia, USA. Fruits are about 2.5" (6cms) across.
Morton citrange leaves are a particularly dark green, and the side leaflets often overlap the central portion.
A Troyer citrange growing outside in my garden in England
This complex hybrid, sometimes still called a citrange, and sometimes used a rootstock, is said to be closest yet to the goal of a hardy sweet orange. I believe it is probably also the variety sold as 'Snowsweet.'