Five golden rings: Yorkshire's poshest Christmas trees

“No bauble can touch another bauble. There can’t be more than one bauble on the same branch and the thread has to be the same length on each one,” she says, turning round a Christmas present in one of the rooms so that the bow faces the front. “I swear they move things around just to see if I notice.”

As Castle Howard’s retail manager, the festive design of the house is down to Kelly who will begin dreaming up next year’s design in January.

“I’ve been here 11 years now and each year it gets a little bit more outlandish. Visitors now expect Castle Howard to go large at Christmas and we can’t disappoint. The scale of what we do is incredible. This year for the first time we have put a garland around the archway of the first steps people walk up. Just for that we had to get the scaffolders in. One of the lads asked what we were doing and when I said we needed it to put a Christmas decoration up you could tell he thought I was nuts.”

While the Howard family sign off Kelly’s designs she says they have never objected to any of her suggestions.

“There are some rooms where it feels right to have a picture postcard tree with all the trimmings. And others where I can be more experimental, like this.”

We’ve arrived in the dressing room where the centrepiece is a Christmas tree made of books.

“When I told our head of collections what I wanted to do I think he thought I had lost the plot, but people here are very good. They go with me. What you can’t see is that we’ve threaded ribbon through the books so we know which shelf they need to go back on. We are all a little OCD around here.”

Elsewhere in Lady Georgiana’s dressing room, which has been overtaken by a giant pile of presents, another tree is decorated with blue and white china cups and saucers while an upside-down tree has been suspended from one of the ceilings.

“I went out and chose that one myself. It took a while to work out how to get it out of the ground with the roots intact, but once we had we sprayed them gold – bingo,” adds Kelly.

In one room there is also a miniature replica of Castle Howard made entirely of gingerbread.

“We wanted it to be to scale and to include all the different elements of the property, not just the main house,” says Sam Bompas, of Bompas and Parr, known for making edible works of art. “We used the same computer software that an architect would and then flattened the design out. Basically it’s a bit like making a piece of Ikea furniture in reverse.

“Most of it was constructed off site, so it’s always a bit nerve-wracking when it comes to transporting it, but I think it looks fabulous. Also because the gingerbread recipe we use is low in fat and butter it will survive for years so I am hoping the house we’ve made won’t just be for Christmas.”

Nothing at Castle Howard is done on a small scale. There are 42 trees lining the driveway and inside the house the main 28ft tree, which took 12 men to manoeuvre into place, requires 2,000 baubles alone.

“It takes us two weeks from start to finish to complete the decorations and this year one of the peacocks tried to kill me,” says Kelly, who is sporting a nasty gash on her arm after one of the decorative birds fell while they were trying to fix it in place. “Some of the colour schemes mirror the wallpaper in the room itself, but a lot of people have been asking why there is a black swan on each of the white trees in the Garden Hall. I know they want there to be some deep and meaningful reason but I just thought it looked good.

“There is an area of the storeroom they call Kelly’s corner which is full of things I’ve found on the estate which I think might just come in useful. We rarely buy props in because there is no shortage of beautiful things all around us. A few years ago for example we found a doll’s house. It had been made for one of the children in the 1920s and while it was in pieces it still had the original curtains attached. We had it rebuilt and it’s now one of the centrepieces of our Christmas trail.”

This year’s theme is “bringing the outside in” and Kelly’s right-hand woman is head of gardens Adele Hirst.

“I just do what she tells me,” says Adele. “In fact, when it comes to Christmas everyone does what Kelly tells them. Where possible we use as much natural foliage as possible. There are a couple of rooms where the humidity means we have to go artificial and the festive hat they’ve put on Fortuna this year isn’t real because we have to protect the marble.”

Fortuna is one of Castle Howard’s most familiar figures in the sculpture gallery and this year she is sporting some particularly festive headgear, but it’s a rare corner of this stately pile that hasn’t been given a makeover.

“I’ll have to change the main garland up the steps at least once and the big tree will also have to be swapped, but with careful watering we should be able to make everything else last. I come in every morning before the first visitors arrive and spray everything. It has to look exactly the same when we close the day before Christmas Eve as it did the day we opened,” adds Adele.

It’s the same story at Chatsworth House where preparing for Christmas is a year-long job,

“We already have a sketch design for 2017 and we will soon start thinking about the year after that,” says textile department supervisor Susie Stokoe. “There are 24 spaces that need to be filled and the design of the route is so important. This year we have gone for a Nutcracker theme. Each room has been transformed into a scene from the ballet and the fact we have live dancers really makes the whole place come alive.

“We had talked about doing The Nutcracker for a number of years, but I was slightly nervous as it is something that has been done so thoroughly by so many people, but I think it looks just beautiful. I said to one of the ballerinas the other day: ‘Imagine how many people’s photographs you’ll be on this year’ and it’s true the response from the public has been incredible.”

Like Castle Howard, Chatsworth gets ready for Christmas while the property is open to the public. That in itself brings its own challenges and Susie admits that everyone holds their breath when the biggest trees are brought in.

“It’s always a worry that something will get damaged, but we are a pretty polished team. It is a really special time of year at any stately home and while I am biased, at Chatsworth what I hope we give people is the true spirit of Christmas and I think you do have a very special atmosphere in a property like this which is not just historic but is still a family home.”

So do those behind some of the most lavish festive decorations in the country have any tips for turning your own home into a winter wonderland?

“Oh God, no, I don’t even have a tree,” says Kelly. “My house is a tinsel-free zone.”

“I am thinking after seven years of decorating Chatsworth that maybe I should embrace Christmas at home,” says Susie. “But that will only mean buying a wreath for the front door. When you have a job like this you soon develop bauble-itis.”

Castle Howard is open for Christmas until December 23. 01653 648333, castlehoward.co.uk. As well as its usual daily opening times, Chatsworth House is also open Thursday and Friday evenings until December 16. 01246 565300, chatsworth.org