How about creating a personalized seed saving kit for him. You can add packets of different seeds that he loves and artfully package it in a decorative tin or a wooden box. You can also add some gardening gloves, a small notebook to keep track of seed growing, and a plant label marker. Additionally, you might want to consider adding a guidebook on seed saving techniques or even a gift card for a gardening store. This will let him know that you pay attention to his interests and enjoy supporting them.
Or you can get him a star map with the date of your anniversary.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.