Roses in winter
Despite the graceful and delicate appearance of their flowers, roses are vigorous shrubs, which bear the succession of climates well. These are semi-evergreen plants, that is, they behave like evergreens when the climate allows them to vegetate at best, while they lose most of the foliage when the climate is less favorable.
This means that we can find ourselves with rose bushes with few leaves even in August, if it is very hot and it does not rain (or we do not water the garden), just as this can happen in winter, if for many days the temperature goes below of zero.
In any case these shrubs do not fear the heat and the cold, that is they are not irreparably damaged, therefore as soon as the climate returns more mild the plant resumes to vegetate fully, and to produce new leaves and new buds.
This behavior of most hybrid roses means that the flowering period is very long, and depends mainly on the climate; obviously if we live in Bolzano it is probable that the roses bloom from April until September, without interruptions, and that then they lose part of the foliage and enter a period of vegetative rest. If instead we live in Sicily it is likely that our roses will rest in August, but that perhaps they will give us some flowers even in November.
To obtain beautiful flowers already in early spring it would be better to have our roses already in the autumn; in this way they will have the possibility to develop a good root system before winter and a very cold climate, which allows them to produce lush vegetation already from the end of winter. Remember that most modern hybrid roses bloom on new branches, those produced in the current season; therefore to always get new flowers we will constantly have to stimulate our plant to produce new shoots, new branches and therefore new buds.
The cool climate and short days tend to slow or stop the vegetation of the shrubs during the autumn and winter months; in most of the regions of northern Italy, during a normal winter season, roses hardly produce new branches and new flowers; in most regions of southern Italy in winter the climate is mild, but the days are short, so even if our roses bloom, they hardly produce a large number of flowers.
So we can sacrifice any winter flowers by pruning our low roses already in autumn, if we live in the south-central, or towards the end of winter if we live in the northern regions, with a very harsh winter climate.
This practice involves the shortening of all the most vigorous branches, leaving only 2-3 buds, and the removal of the smaller and weaker branches.
In this way, when the plant starts to completely vegetate again, with the arrival of the months with a mild climate and with the lengthening of the days, we will favor the development of a large number of new shoots, equivalent to a large number of future buds.
Most hybrid roses do not fear the cold, and can withstand temperatures close to -10 / -15 ° C even for a fairly long period of time. Obviously we will have to place our rose plant in a very sunny place, so that at least the warm winter sun warms them a little.
If we live in a place where winter is definitely very rigid, with persistent snowfall for a few months, we will have to place our roses in the sun and in a sheltered place, for example in a flowerbed near the house, exposed to the south or south-east, so that it enjoys a slightly less cold climate. Certainly we will also have to get ready, at the beginning of autumn, to mulch the soil around the plant with dry leaves and straw, so as to prevent frost from penetrating excessively into the soil, until it reaches the root system.
If we want to be even more peaceful, after having mulched the soil well, we cover the plants with the woven fabric, to be secured to the ground with stones or metal jumpers, so that the weather does not move it: in this way we will create around to plants a microclimate that will preserve them from the most intense frost.
We avoid covering them too soon, otherwise we will find plants with shoots in the middle of winter.
Before it's too late
Even if we do not decide to prune our roses in the fall, it is good to do some maintenance before the cold comes, so that we can carry on through the coming spring.
First of all we practice an anti-fungal treatment, especially on plants that have suffered from scab or other fungal diseases during the summer.
Most fungal parasites present on roses generally remain dormant in the soil until the next springs, when they can undisturbed return to the tender newly developed buds; to avoid this, let's spray the plants with an antifungal, but also the leaves around them; if possible we remove all the leaves affected by fungal disease and burn them, so that they are not vehicles of further infections.
When we prune our roses we always remember to use sharp and disinfected pruning tools, disinfecting them at every change of plant, so as to avoid being ourselves a vehicle of infection between one plant and another.
Most of the botanical roses originating in Europe are deciduous plants, which in winter go into complete vegetative rest; some botanical species of Asian origin instead tend to keep the foliage even in winter.
Most botanical roses also tend to bloom on the branches of the previous year; so if we want to get lots of buds in the spring we avoid pruning our botanical roses together with modern hybrids, otherwise we will remove most of the flowers. Pruning of these roses takes place after spring flowering.