Roses are not the best plants to grow in a continental climate but for some reason expats like myself seem determined to have them, come what may. But anyone who has visited the gardens at Venzano near Volterra or the private gardens at Sant'Arcangelo overlooking lake Trasimeno will know what can be achieved if you pick the right rose and treat it properly.
I will talk about specific roses in a separate blog but here are a few thoughts on growing roses where the summer is hot and dry but the winter is cold.
I hate to say this but I have not been entirely happy with many of the roses I have bought from local vivai (garden centres) unless it is something terribly ordinary like Iceberg. I find that named roses and old fashioned roses tend not to come quite true to type - for example, the Zephirine Drouhin that I bought from the exalted Vivai Margheriti is too pale a pink and lacks the intense carmine shade that it has in England. All the roses that arrived by mail from Peter Beales have done very well. Harkness were disappointing: of the 5 rose bushes named Susan Daniel (a friend of mine) one turned out to be red and another died even before the spring arrived. But the three survivors are fabulous. A lot of local suppliers offer a wide range of Meilland roses but I have not tested the Meilland from the original breeders in France to make a comparison.
Site and soil
A Med Garden Soc member who breeds roses in Liguria told me that roses really like clay. Well that's just too bad: here I have essentially stones with a bit of dust in between. The challenge is to get some humus into the soil. Farmyard manure is like gold dust (see another blog on this topic) so I have to use stallatico, which is stable manure dried off and packaged in bags.
To help the poor plant conserve moisture in summer it is essential to mulch around the roots with bark or anything else that comes to hand. This is the single most important gardening technique that I have found.
Climbing roses are, by nature, plants that grow in woodland and reach up to find sunlight above the tree canopy. It follows then that a good place for them is with their roots in the shade and head in the sun, if possible. My Zephirine Drouhin was burned by the sun this sumer despite being mostly in the dappled shade of an olive tree. The leaves will grow back in the autumn but it looks unsightly in the meantime. A pergola is a good way to get the shade onto the foot of the plants: best to use climbing roses or ramblers with slender, pliable stems, otherwise it can be struggle to get them to bend to the shape of the frame.
The shrub roses in the vineyard though just have to tough it out in full sun: grapes are happy with roots in stones and blazing sun all day, so better get to like it. The Chinese roses are a little shy of the cold but seem to withstand frosts, so in fact they do alright here.
Pests and diseases
Roses catch all the same diseases as grape vines but show signs of distress quicker, which is why they are often planted at the end of rows of vines in order to act as an early warning system. Roses therefore have to be checked early in spring for signs of fungal attack then sprayed with the same stuff as goes on the vines.
Black spot is a major problem here too. Regular spraying with Rose Clear helps keep it in check but making sure that prunings and dead leaves are taken away is also important for prevention. A Med Garden Soc friend disinfects the soil around her roses every autumn using Jeyes fluid - which you can't buy in Italy. She comes back from trips to England with it secreted in the suitcase. Are we mad or what?
I used have trouble with deer eating the roses but then hunters came and shot them. Tragic. I would rather have sacrificed the flowers.
There is a lot of hype about pruning. The Royal Horticultural Society recently published an article where they revealed the truth which is that pruning does not really matter all that much and you can hack them back with a hedge trimmer and it makes little difference. I do not prune the Chinese roses or climbers. More important for climbers, I find, it making sure that the stems are bent over so that they sprout side-shoots, otherwise there is a tendency for the lower part of the plant to be bare and leggy.
It is impossible to buy bonemeal or decent rose food in Italy. A guest speaker at the Giardino Romano club recommended bonemeal and when asked where to buy it she replied 'England'.
Foliar feed is surprisingly effective: when spraying the vines for disease it helps to add liquid feed - I use this same mixture for the roses and they enjoy it. I have also tried seaweed as an organic foliar feed. It is supposed to help the plant photosynthesise better in the hot weather and I think it helped but carries the disadvantage of leaving brown splashes on the leaves which are not so attractive. If a rose is looking a bit feeble then a dose of oxblood diluted in water is a good tonic.
The Royal Horticultural Society has run trials and found that roses don't really care whether they have organic or chemical food. I prefer to be on the safe side and use bonemeal, stallatico and Top Rose, which I bring from England.