Left empty after the troops departed, by 1945 the fitments of the house were put on sale and the Estate began to fall into disrepair. By the 1950s the House was demolished. The great oaks, which had been so cherished by Thomas Phillips Price were felled, presumably for the value of the timber. The deer park was overgrown, the Walled Garden was a tangle of weeds and the lakes were silted up.

So it was in 1966 that work began to preserve the future of this once great Estate. Despite the alarming level of dilapidation, real potential could be seen in the landscape. The directors of Kew and the Agricultural Land Service recognised Marks Hall was something special and worth saving. Marks Hall began being talked about as a potential Arboretum. This perhaps, could be a way to fulfil the wishes of Sir Thomas Phillips Price and reflect his passion for the trees.

First a Charitable Trust was established in 1971. Then a concerted programme of renovation, clearing and landscaping began. A master plan was drawn up, and work began on the development of an arboretum of national significance, with scientific and educational value. 

Marks Hall Gardens and Arboretum has been opened to the public since 1993. The Arboretum today is a collection of trees from all temperate areas of the globe. They are mass planted in geographic zones within the heritage landscape. It makes for some striking views and vistas across the Essex countryside.

Now with annual visitors of over 40,000; over 1,400 annual members and an industrious team of 80 volunteers who ably assist the staff team, it continues to inspire all those who visit.