More than two decades ago, Sue Manners painstakingly began to pull up the turf surrounding her Elizabethan home to turn it back into a glorious garden. Now, each year, she throws the gates open to the public so we can all enjoy the stunning results of her creativity and back-breaking toil

IT is 21 years since Sue Manners set out to transform the land surrounding 16th Century Thornton Hall from a paddock into a beautiful walled garden. And since 2005, when she first decided to share this magical plot with the public under the National Gardens Scheme, raising money for charity in the process, visitors have flocked in to see what she has achieved.

Many have left amazed. Sue has put years of back-breaking work into slowly converting a blank canvas into the beautiful floral extravaganza we see today and the result is a joy to behold. It is perhaps one of the most important private new gardens to have been created over the past ten years and, in tribute to her skills as a plantswoman, she has rightly been called “the Beth Chatto of the North”.

Thornton Hall, near Darlington, was originally built in about 1550 by Ralph Tailbois and three distinct walled gardens were created, with magnificent Elizabethan raised borders – unique in this area – so that the ladies could sit and admire their flowers without moving. Then in 1696, the infamous window tax came along, the hall fell upon hard times and the gardens disappeared and were replaced by orchards.

It was 300 years later that current tenants Sue and her husband Mike decided they wanted to make something out of the gardens, which were being used as paddocks and grazed by cattle and sheep. Work started in 1995. "There was never any grand master plan. The garden just evolved," says Sue.

She lovingly began to plant up the first one-acre walled garden with no knowledge of gardening whatsoever. In the following years, helped by family and friends, she has created one of the most stunning gardens in the country.

This is very much a plantswoman's garden, housing many unusual and rare perennials, including large collections of peonies, delphiniums, hostas, roses, lupins, heucheras and clematis. These are interspersed with interesting trees and imaginative shrubs in a profusion of mixed curvaceous borders and island beds.

Sue is particularly proud of her collection of hostas and the garden's north-facing border is dedicated to more than 250 variants of this intriguing plant. "I love finding the right places for my plants,” says Sue. “I always say they get dizzy in my garden because they go round and round until I've found the ideal spot for them."

A garden like this is just made to be shown off and Sue and Mike open its gates each year to raise money for charity. The open days are so popular that they have been able to raise large amounts of money even when it's been rainy and blustery. There isn't much that can deter visitors from coming in their hundreds to see this beautiful and colourful patch of County Durham.

What are your latest projects?

Every year sees a new project. Over the past year we have been renovating the Chapel Folly, which is almost finished. An old font has just been added. The folly has lovely views back to the hall, so you can appreciate the original architecture from 1550, as well as the newer addition from the mid-1600s. More seating has also been added around the garden where visitors can sit, ponder and reflect.

Where is your favourite corner?

It changes as the year progresses. In spring, it’s the corner directly in front of the hall, where snowdrops, crocuses, primroses and hellebores all announce the arrival of spring. Then I progress to a very peaceful area to the right of the pavilion to watch the shy waterhens making their nests on the pond, followed by the arrival of the swallows who love to swoop down onto the pond and quickly back up again, just playing with the water. On a warm summer evening the tranquillity, peacefulness and scent that the white garden has to offer is breathtaking. Finally, as we reach late summer, my favourite corner changes again to the thatched swing in the hot border where all the dahlias, cannas, heleniums and crocosmia offer us a riot of colour in red, orange and yellow. I enjoy the odd glass of wine at 6pm in the summerhouse where I can catch up on the day’s events with my husband and enjoy the last of the day’s sunshine.

What wildlife do you have in the garden?

A huge variety, from hedgehogs hibernating in the winter to the oyster catchers which return mid-March, often nesting on top of the gunnera beside the pond. Amongst my favourites are the song thrushes, woodpeckers and wagtails and we only realise how many birds we have when we are cutting back in the autumn and find a large selection of nests all beautifully disguised among the shrubs and trees. We have a pair of apricot call ducks on the wildlife pond which, as well as producing numerous cute ducklings, are also good at keeping the garden slug population down.

Which garden implement could you not do without?

My Flymo contour cordless grass trimmer and lawn edger, the quick and easy way to trim and edge the contours of your lawn.

Which are your favourite plants?

That’s never an easy question as every season my favourites change and plants can be favourites for different reasons. I like to have something scented, whether it be a Sarcococca confusa, Daphne bholua "Jacqueline Postill" or Viburnum Carlesii in spring or Philadelphus Belle Etoile (the single-flowered mock orange blossom with the orange centre) in July. These plants all stop you in your tracks with their intense scents.

Plants can also be favourites because of their sentimental value. In our family, we quite often buy presents of plants, shrubs or trees to celebrate special occasions such as birthdays, anniversaries or weddings. I have a fabulous Prunus serrula, which my daughter Victoria and son Will gave me for my 40th birthday. I love its polished, red-brown, mahogany-like new bark as well as its stunning autumn colour. Likewise, we planted a very impressive Trachycarpus Fortunei in front of the ornamental pond in August 2014. This incredible palm was used as the centrepiece in the marquee for our daughter Victoria's wedding in July 2014 and brings back wonderful memories of a very special day.

Do you feed the family from the garden?

Yes, from an ever-expanding vegetable/fruit garden. The difference in flavour from supermarket fruit and veg is huge. I think at times people have forgotten what flavour is. We love all vegetables and enjoy growing and experimenting with lots of varieties but our favourites would have to be asparagus, leeks, spinach and parsnips. We have one peach tree on a south-facing wall and it never fails to produce a good crop. They don’t store very well and need to be consumed immediately, but we usually have plenty of takers for this job.

Do you go on plantswoman’s holidays?

I love going on plantswoman's holidays. I don't know if my husband Mike would agree, but he usually comes along too. Every year we will visit a different part of the country, from East Anglia to Cheshire, fitting in as many gardens as I dare. Currently my two favourite gardens are Gresgarth Hall, in Lancashire, home to Arabella Lennox-Boyd, and Sissinghurst, in Kent, designed predominantly by Vita Sackville-West.

Looking back at the past 21 years at Thornton Hall, what are you most proud of?

I have just really enjoyed having a complete blank canvas and being able to do exactly what I have wanted in such a beautiful setting around a Grade I-listed hall. I have planned every part of the gardens, sourced and bought every plant (except the presents) and planted every plant. There are not many people who are fortunate enough to say that. And I am very proud of the many thousands of pounds that the garden has already raised for charities.

In the past 20 years, I have learnt that a garden is actually not dissimilar to children – you nurture, cajole and hope that your efforts will be fruitful; you suffer agony when a particular specimen struggles to survive; you wait anxiously to see how a plant will fare in a particular place. You feed and water your plants; you suffer huge anxiety if they don't grow; and on reflection, the only real difference between growing plants and raising a family is that you don't have to change the plants’ nappies or wash their clothes. And most importantly, they can't answer back.

I also learnt to be patient because a good garden takes years of planning, investment and foresight. Gardening can be back breaking, but it is also a great way to keep fit and beats going to the gym any day. I can't see myself ever hanging up my trowel for good.

OPEN DAY DATES FOR 2016

(11am to 4pm)

Bank Holiday Monday, May 30, including entrance to Specialist Plant Fair in the Courtyard with many rare and unusual plants for sale.

Wednesday, June 15, in aid of NGS;

Wednesday, June 22;

Sunday, June 26;

Wednesday, June 29;

Wednesday, July 6;

Wednesday, July 13;

Sunday, July 17.

Homemade light lunches and afternoon teas are available. There are no picnic facilities. Wheelchair friendly. Group bookings available. Admission £6. Plants for sale.

For further information, visit thorntonhallgardens.co.uk