How about getting him a planter box or raised bed garden? This would allow him to grow a variety of plants and herbs right on his balcony or patio. You could also consider getting him some high-quality soil, a variety of seed packets, or gardening tools he may need. Another idea could be a book on gardening or attending a local urban gardening workshop together as a gift.
Or you can get him a star map with an important date you share.
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.