The capsule, which contained pictures, paintings with a theme of town life, also carried depictions of what the children thought old age would be like and was set into the ground at West Hall, the former home of engineering company Mouchel that is now a care home.
Some of the new residents of the home, which allows independent living, also contributed to the capsule. It is planned that the capsule will be opened in 2037, 25 years from now.
Jonathan said: "I was very pleased to be able to preside over the planting ceremony and was impressed with the enthusiasm of the children and the effort they had put in."