Publication : 2008
We publish hardiness observations that we consider of high interest.
They are reported in various languages other than French.
The observations may concern the death or the survival (with various levels of damage) of a plant.
We must be rigourous and do not forget, as far as possible, the following details when reporting hardiness observations.
General informations about location, local climate and soil conditions.
Age of the plant.
Height of the plant.
Negative temperature which killed the plant or was whistood by it.
General wheather conditions relative to the period including the observation (number of days with negative temperatures, snow or rain, wind etc.).
Possible existence of factors having contributed to reduce the frost effect (plant entirely covered with snow, protection against the main winds by trees, bushes, wall, house, location on a well exposed slope with drained soil, mineral blocks spreading during the night the accumulated diurnal heat etc.).
Morus nigra is less hardy than Morus alba.
For the people who live in the borderline for Morus nigra to survive, I give evidence that some Morus nigra varieties are extra hardy.
If you select these varieties, it is possible to grow Morus nigra under wheather conditions that, in general, this species doesn't withstand.
I live in Austria, 80 km east of Salzburg, 420 m above sea level. Average annual temperature 6...8°C, precipitation 1800 mm. Winters may bring -18°C during 2 or 3 weeks.
I bought a Morus nigra 'Bigfruited' from the Netherlands 20 years ago. It died a year later.
In 1988 I got two ordinary Morus nigra (each 80 cm tall) from the Hungarian wine region (20 km south of Bratislava, Slovakia).
They started fruiting 2 years later, and they fruit every year (3 kg at least drop to the ground).
Morus nigra är mindre köldhärdigt än Morus alba.
För dem som bor i områden där Morus nigra är på gränsen till härdigt, kan jag tala om att det finns varieteter av Morus nigra som är extra härdiga.
Om man odlar dessa varieteter är det möjligt att odla Morus nigra under förhållanden som denna art normalt inte klarar.
Jag bor i Österrike, 80 km öster om Salzburg, 420 meter över havet. Den årliga medeltempreaturen är 6-8C och den årliga nederbörden är 1800 mm. Under vintern kan temperaturen sjunka till -18C under 2-3 veckor.
Jag köpte ett Morus nigra "Bigfruited" från Holland för 20 år sedan. Det dog ett år senare.
1988 fick jag tag på två Morus nigra (vardera 80 cm höga), vid den ungerska vinregionen (20 km öder om Bratislava, Slovakien).
De började sätta frukt efter 2 år och har därefter satt frukt varje år (minst 3 kg som faller ner till marken).
CRATAEGUS AZAROLUS (Cultivar 'White Italian')
I live in Gothenburg, Sweden.
Two years ago, I grafted a plant of the yellow fruited Crataegus azarolus 'White Italian'.
I planted it out last year in a place which is protected from cold northern and eastern winds. It was about one meter high.
At the same time as 'White Italian' I had grafted a second plant of Crataegus azarolus species (an unnamed cultivar which produces big red fruits, selected by a French Mediterranean nursery). This other azarole plant, also one meter high, was planted about ten meters away, in a wind protected site.
I would say that there were almost the same conditions for both the plants.
This winter was unusually cold and the cold also stayed for over two and a half month.
The snow cover was also heavy, up to 75 cm.
We had a lot of nights with temperatures under –15°C and for one night it reached –19°C.
Quite a lot of plants died for me this winter, for example Vitis, Cudrania, Broussonetia, Ficus etc.
These conditions were perfectly whistood by the 'White Italian' cultivar, which was very healthy after this awful winter, even for the part above the snow cover (which is a factor reducing the frost effect).
In January I discovered serious damages on the other azarole cultivar, and in March I noticed that it was dead.
This may indicate that 'White Italian' could be hardier than other Crataegus azarolus cultivars.
It will be interesting to observe the future behavior of 'White Italian' for a long period to determine its real hardiness...