This year have been lucky enough to source a range of cold tolerant citrus.

I live 4miles to east of manchester at the foot of the pennines. Like most of UK we are zone8 but also in the Liverpool-Manchester heat island.

Main problem is that we are very rainy and are therefore heat zone1. Summer would usually be low to mid 20's*c rarely mid to high and even rarer 30 or more.

Put my citrus under fleece 30 october.

Since then had 4hrs frost (18-19/11 -0.2*c, 22-23/11 -2.4*c, 23-24/11 -1.8*c and 25-26/11 -1.6*c) daytime temps between 5-13*c.

Temperatures under the fleece have dropped to a low of 4*c.

Under the fleece the only variety that is defoliating is cisuma. Citranges, citremons, citradia, citrandarins, citrumelo, citrangequats, ichangensis and its hybridd are still green and healthy.

So far am not deluding myself that with protection at least so far I may be successful eith my potted collection and just have to find a method for in ground culture undrr my conditions.

good luck with your Citrus collection......keep the updates coming.

Have tried poncirus in open ground died of rootrot - soil too wet in winter. Have just moved them from pot to tomato pot.

For those not familiar a tomato pot is open bottomed so allows the plant free access to the soil whilst raising roots above any water logging.

Flying dragon outgrows pt in pots here. Maybe flying dragon is just in bigger pot and has more stable soil conditions.

US119, morton, troyer and carrizo survive most winters here on their own roots through winter in pots but put on no growth. C32 and C35 seedlings did well for a decade putting on growth. C35 went in the first of 2 unusually cold winters and C32 in the following. I don't think low got to -10*c.

All my current plants are on poncirus rootstock bar one which is on swingle citrumelo.

Hi yuzuquat,

I am more to South than you, 48°N, formally middle of USDA z8 ( average yearly minimal around -10C), but in January and February the freeze sometime stays for weeks. This year up to now we have had three short night frosts, the lowest with -1.7C.
My garden is on the slope, soils are fertile loess, poncirus is growing without any problems and fruiting every year. I tested a multitude of hardy hybrids, the completely hardy up to now is my variant Swingle citrumelo (Swingle5* ) and ichangquat 6-7-2, both from B.Voss. They are flowering and fruiting every year. Citrange Morton and citrangequat Thomasville are also growing fine and bringing a lot of fruits but suffering one winter in four.

Thanks Ilya and T
Will keep an eye on real measured temperatures here throughout the winter.

Don"t think winter cold is my real problem here rather the lack of summer warmth and amount of rain.