The Diaplant method

At Diaplant, almost every tree grows in open ground. Not in plastic pots, not in artificial substrate — in soil, in the field, in Amarante. And every three to five years, each tree is lifted, its roots are pruned and the specimen is replanted in another plot, with more room. This cycle is repeated over years, sometimes decades, until the day the tree leaves the nursery for its final destination.

The technique has a name. In German it is called Verschulen — literally, “re-schooling” — and it was born in the nurseries of northern Germany and the Netherlands in the second half of the nineteenth century. Carlos Azevedo learnt it from nurserymen in those regions and brought it to the 33 hectares in Amarante, where he applies it with the adaptations that the Iberian climate and soil demand. In the Iberian Peninsula, Verschulen is practically unknown. Diaplant is one of the few nurseries — perhaps the only one — to adopt it as its main production method.

The principle is simple: each transplanting forces the tree to regenerate fine, active roots close to the trunk, building a compact, cohesive rootball. At the same time, the crown is trained, the balance between the parts above and below ground is assessed, and the tree gains a readable history — not only of growth, but of responses. A tree that has been through four or five of these cycles has already proved, repeatedly, that it knows how to move. The rootball comes out whole. The roots grow outwards, radially, instead of circling round themselves as they do inside a plastic container. The result is a tree better able to establish itself at its destination — and to keep growing once it is there. There are occasional cases where a container makes sense, and in those cases it is used. But the rule, at Diaplant, is the field.

This work demands constant observation. Some decisions follow protocol, and some depend on reading the specimen directly: the species, the girth, the vigour, the transplanting history, the behaviour of the rootball, the exposure to wind, the soil that will receive it and the effect intended in the project. The team knows where each tree comes from, how it behaves and what its limits are — and it is that connection that allows each decision to be adjusted to the actual specimen, not just to a reference on a list.

Nor does the Diaplant method end at the nursery. Choosing the tree, transport, unloading, planting, staking, the first watering and aftercare are all part of the same chain. A mature tree is not simply produced. It is prepared to go through that whole chain — from our field to your garden — without losing what it gained over years in the ground.