Owen Paterson had "no indication" his wife was suicidal in the weeks before she killed herself, an inquest heard, as the MP paid tribute to her "devoted, loving" character.
Rose Paterson, 63, was found dead in remote woodland near her home in Ellesmere, Shropshire, on June 24 after looking up ways to take her own life on the internet.
The mother of three, who was chairwoman of Aintree Racecourse, committed suicide by hanging, the senior coroner concluded at her inquest.
Mr Paterson, the Conservative MP for North Shropshire, said he had no idea his wife of 40 years was intending to take her own life.
"Rose had a number of plans for the next following days," he said in a statement read at Shropshire Coroner's Court.
"She would be having a remote call and was due to come to London to celebrate my birthday. On June 25 she had a TGV train ticket to France to see our daughter. She was not suffering from depression and she was not taking medication.
"I had no indication Rose had been thinking of taking her own life."
Mr Paterson said the coroner's verdict that she hung herself was "tragic" for everyone who knew her.
He added: "Rose will be remembered as a devoted, loving wife, mother and grandmother, as well as a most successful professional in her varied careers in the arts, charity and racing.
"We are still a long way from beginning to come to terms with her death."
The MP said he had texted his wife at 10pm on the day of her death asking her to ring him, but received no response. The last person to see her alive was her son at dinner the night before.
Louise Lane, a long-term friend of the Paterson family, told the court she had been acting "out of character" before her death and hadn't said hello when she saw her.
Recording a conclusion of suicide, the coroner said Mrs Paterson had a "previous history of anxiety and depression" and police found no suspicious circumstances surrouding her death.