A tangle of elders and brambles at the foot of the northern slope of the valley has now been replaced by the first 50 trees of the new St Herefrith Plantation - named after an early Christian Martyr slaughtered by the Vikings in Louth.
A mix of specimen native varieties went in this week.
The second tranche of 50 trees will be planted in the autumn, with hundreds more to follow after that.
Following the Trust’s long-standing policy, established trees are always bought to ensure they have the very best chance of survival.
Meanwhile, the toilet block roof was removed due to leaking skylights, and this has now been fixed.
A Hubbard’s Hills Trust spokesman said: “The plan had been to simply replace the skylights, but closer investigation revealed the felting had disintegrated and major works were needed.
“A team of local builders were soon on the job and the roof was quickly replaced and should now be good for another few decades!”
The spokesman added: “Other major changes at Hubbard’s Hills are now in the planning stage, and the damaged bridges in the Hills will also be replaced in the near future.
“Possible designs are being considered, considering the need to deter the ever-increasing vandalism that the Hills are suffering.
“Moves will also be made to stop visitors destroying the amenity by creating mud slides. The rain shelter is also due to be restored.”