The left-hand portrait, below was painted by John Linnell in 1840 and purchased by the Linnean Society in 1877. From the sadness on his face one can surmise that Loudon was becoming aware that his his health would not allow him to carry through the many projects he would like to have completed before his death, in 1843.
The date and of the portrait on right is unknown but it was published posthumously, in 1845, as a frontispiece to his Self-instruction for young gardeners. Judging from the comparative youth and optimism of the drawing one can suppose that it dates from the time of his wedding (1830). The fact that it was published by Jane Loudon offers some support for this conjecture. John Martin, a witness at their wedding is a possible artist but is not known to have done any comparable work.