Three years ago I planted 3 Alnus cordata (Italian Alder) along the top of the forest garden, all at the same time.
Italian Alders are great: they’re nitrogen fixing, very fast growing and you can raise the canopy to let in light for plants below.
One of the trees had root damage from voles living under the mulch, one had sawfly damage and has gone off on a tangent. The third (pictured above) has grown straight and proud.
I bought a replacement whip from Ty Rhos Trees, be interesting to see how quickly it can catch up.