Genus: Lycium

Many thanks for both of you for the answers and patience :)

I hope that with a little help all my plants will survive the winter!

Thanks again
Moni

Well the R.H.S. Encyclopedia of Garden Plants, gives the same degree of garden hardiness to my Zantedeshia of two frost symbols as your two less hardy Vaccinium, and my Arum has lived outdoors for 20 years and the books hardiness rating describes 2 frost symbols as being hardy down to -5 degrees, in fact with a little protection (winter mulch) my plant has survived down to -10 and probably less, so in your case, at least for the first couple of years I would just cover them with a bit of fleece but only when deep cold is forecast, otherwise they should be fine, but poaannua has a point if you live at a higher altitude than me at about 100m above sea level, you would want to consider permanent winter protection most frost hardy plants will survive short period of less than the labels suggest, but if the temperature is constantly less then fleece and dry mulch of bark or something is the way to go

Hi Moni. The tmperature here goes down to between -5 and -10 C.. I don't protect the Lycium barbarum, but suggested your doing so as I imagined your temp. would be much lower, at such a height.. Bedtter safe than sorry.
Best Wishes.

Thank you John for the details! Do you know the real hardiness of the V. floribundum and the V. cylindraceum? Do you think that wrapping with that thin white garden fabric would be enough protection to them?

Peter, I read everywhere that Lycium barbarum is hardy to -15 degrees. How do you protect yours? And what are the minimum temperatures where do you live?
Thank you for the info about Debregeasia. I think I'll plant it outdoor next spring, than protect it during winter...

I think you should protect the Lycium of both kinds.
Debregeasia edulis Is not reliably hardy, It should make a 6ft. shrub but at Arnold Arboretum is cut down to ground by frost but regrows.Although it does not flower or fruit the leaves are so attractive with their contrasting bright green upper surface and white under surface they are worth growing
Quoting from @The Standard Cyclopaedia of Horticulture' by L.H.Bailey. A work now much out of date..

Debrageasia edulis, no idea
Vaccinium Nummularia: Grow in acid peaty soil, or sandy moist but well drained soil in full sun or partial shade, borderline fully hardy grows to about 300mm high by 600mm across, native of Bhutan (Himalayas)

Vaccinium Floribundum: same growing conditions as above but not quite as hardy maybe a little more protection from strong winter winds, grows to 1m high by 2m across, native of Ecuador and Peru.

Vaccinium Cylindraceum; again same requirements as above but again a little less hardy than Nummularia, grows to 2.5m high by 2m wide native of the Azores, but is a R.H.S. medal winner

Thank you John and Peter for the replies!
Sorry for my terrible English, but I have torture you with more questions :)
I live on the hills of Bologna, not near the sea, so we have very hot summer and cold, wet winter with minimum temperatures about -10C. This is a very windy places and all my plants are in full sun, being on the top of a hill. Should I plant them outdoor right now or would be better in spring? And are they deciduous or just are not in good shape? I'm asking this because the L. chinenesis has all it's leaves while the barbarum almost nothing. (And no John, these are different plants, the L.barbarum has rounded leaves, the other has oblong ones.)
I bought some other unusual plants (at least here they aren't common), but found very contradictory informations about ther hardiness, but even the final size and form. Could you please tell me something about these?:
Debrageasia edulis
Vaccinium nummularia
Vaccinium floribundum
Vaccinium cylindraceum

Thank you very much!
Monika

I find they live best near the Sea. Mine here get Slugged every year... I know them as The Duke of Argyll's Tea Plant.. It was growing as a hedge at Pwll Gwaelod in West Wales, where mine came from. They should flourish with you. They probably prefer sandy soil and good light.

Lyceum barbarum, you need to grow this in moderately fertile soil in full sun, they apparently don't mind dryish soil and good as a windbreak, I think the chinenses is one and the same thing, as barbarum common name is chinese box thorn

The colouring isa strange blue, but the main difference from the photo on the Victorian Nursery website is the width of the leaves in your picture.

I grew some from seed in two batches and one lot has narow leaves on a single ste,. and later ones look more like a wallflower plant!

Any thoughts?