The family-owned, 85-acre arboretum near Bedale is regularly named in lists of the best places in the country to see the leaves turn.
This World War Two gun post was hidden on a Yorkshire farm for 70 yearsThe majority of the 80,000 people who visit every year do so between September and November - with October half-term the busiest week in the calendar.
Amazingly, this nationally significant collection of rare tree species and beautifully landscaped gardens are maintained by just one full-time gardener and the Ropner family, descendants of a German shipping merchant who have owned the Thorp Perrow estate since 1927. Sir Leonard planted the arboretum in the grounds in 1931 and his grandson, Sir Henry, still lives in Thorp Perrow Hall today with his wife, two children and widowed mother.
The gardens - described as 'amateurish' as their designer had no prior arboricultural experience - were a private family retreat until 1977, when Sir Leonard died and his son Sir John was advised to preserve the tree collection for the nation. It opened to the public soon after.
Thorp Perrow has since grown to become more than just a horticulturalist's delight - it's now a family-friendly attraction with a programme of events suitable for all ages.
Head curator Faith Douglas has seen Thorp Perrow develop significantly since beginning her role 10 years ago, and the former mental health nurse is now helping the family and a dedicated band of 20 volunteers prepare for the crucial autumn season.
"We've seen big changes - the trees have grown of course! We've expanded the wildflower meadows and become more family-friendly - it's important for the future of the arboretum to educate children."
The 18th-century gem in Ripon that's only open once a yearFaith has organised mindfulness walks, photography workshops, fungi tours and the coveted Lunch in the House - a twice-yearly event where guests can enjoy a two-course meal in the Ropners' elegant dining room and a talk by a fungi expert. The highlight of the autumn is the Halloween trail, which is hugely popular with children.
"Halloween is definitely our busiest time, but we deliberately site the trail away from the main tree avenues, as we recognise that different sorts of people come for the leaf displays. Lunch in the House is very popular, the hall is a real family home and we only open it twice a year.
"The colour here is so beautiful - you don't need to go to New England to see incredible leaf displays, they are just as good in this country.
"Sir Leonard Ropner was mindful of the different times of year when he planted the trees - there are three autumn 'bays' that really come to life at this time of year.
"Thorp Perrow is a very beautiful place, and we do see a lot more people coming to take their own photographs now. I do all of the Instagram shots on my mobile phone, but it's good to see people with the proper old cameras too!"
Preparations are well underway for the autumn rush - extra staff have been recruited to help in the tearoom, which started life as a Portakabin in 1980 and has been extended several times since then.
"It's all hands on deck now. We are looking at things like grass management - we have a strict cutting regime as it's important to protect the fungus. Different areas of the grounds need different preparation, and we have to manage the car park too, especially in boggy weather.
"We have one full-time gardener and 20 volunteers. Lady Ropner, Sir John's widow, cuts the grass - it's still very much a private collection and we don't have the cashflow for large numbers of staff.
"Autumn is our shop window, so we have to make sure the grounds are immaculate - the borders need weeding and the paths must be kept clear. The tearoom gets so busy now that we have opened a pop-up cafe in the bandstand."
Guided tours will reveal secrets of Scarborough's oldest cliff tramwayFaith has already observed promising signs that this autumn is set to produce some stunning colours.
"The trees look at their best in the second half of October. The signs are positive - I think it's going to be a good year. 2012 was probably the worst year for the colour, as it rained all year and the trees were affected.
"Last year the colours were very bold and gold, while in 2017 there were more yellows. I have noticed differences in the trees between years, as I keep records - more of them are dropping green leaves now, which I think is due to climate change."
Thorp Perrow Arboretum is open daily from 10am-5pm. www.thorpperrow.com