The majority of today's roses have a grafting point that many gardeners look at with suspicion when it comes to burying it. Opinions are divided on the subject...
What is the grafting point?
Today's roses are often grafted. A variety chosen for its aesthetic characteristics (beauty of the flower, abundance of the bloom, perfume...) is grafted on a resistant rootstock, which makes it possible to obtain plants offering all the qualities required to be appreciated by gardeners. The rootstock allows better resistance to cold, humidity or to a specific soil (acid pH, clay soil...) as well as to various diseases. The more vigorous the rootstock, the more likely the rose will remain healthy.
The grafting point qualifies the part where the graft has been fixed on the rootstock. It can be recognized by the bulge it forms on the stem. On classic roses, it is located a little above the collar (part corresponding to the junction between the roots and the stem). Branches are always formed after the grafting point, but sometimes it happens that the rootstock takes over and branches come out under the grafting point. It will be necessary to cut them to favour the graft.
Questions at the time of the plantation
When planting a rose, the gardener is sometimes at a loss as to where to place the graft. Some recommend to bury it, others not: it is difficult to find one's way...
Everything depends on the region and the planting period. The best time is between October and May, except in high altitude and in heavy soil where it is preferable to wait until March to favour the chances of recovery.
In mild regions and in humid soil, the rosebush should be planted with an apparent grafting point. It is not necessary to bury it. It would risk rotting.
Everywhere else, it is recommended to bury the grafting point, about 2 cm deep, in order to protect it from the cold and to avoid that the rootstock produces suckers. This is particularly valid for the frosty varieties as well as the dwarf cultivars.
Ridging will be done every week during the first two months to keep the grafting point buried. As soon as spring arrives, the protective mound can be removed. If you plant in spring as soon as all risk of frost is eliminated, it is useless to bury the grafting point especially if you live in a mild region.
Generally speaking, if your soil retains excess humidity, think of ensuring a good drainage before planting and prefer to cover the grafting point with a thick mulch of dead leaves to avoid cryptogamic diseases attacking this sensitive part especially if it is constantly bathed in mud.
