New to the sight!! What to get the man who has everything?

Hello everyone, my name is Jennifer and I am new to the sight. I am 26 years old, very happily married with two young boys. I enjoy gardening, however my husband LOVES to garden and in fact has quite the green thumb for a young man. He can name nearly every plant by sight and knows many plants by thier scientific names. He was taught everything by his grandparents who were also very skilled, award winning gardeners. He has grown a vegetable and herb garden every year since he was 5 years old, and has kept a journal of all of his gardening successes and failures as well as a detailed list of every plant he has ever grown (which is probably well over 2000 plants). He turned our mundane backyard into a beautiful French-inspired formal edible garden. He is an amazingly bright and talented gardener and landscape designer. I want to get him something meaningful for our anniversary which is June 20. I was thinking garden tools of some kind but he has wire and garden rakes, shovels, hand trowels, a sharpshooter, and spades. I am on a budget of around $100 as there are other gifts to buy as well. I would like to get him something unique and something he will use. Gifts that simplify gardening tasks or save time or are unique will get more consideration. Thank you all in advance.

What is his favorite plant? Or tree? Get him a high end version.

There are daylilies or hostas that can cost $100, or $200. There are unique rare dwarf conifers that can as well. A unique plant he can garden and grow is a good gift. You won't find these at Home Depot, you'll have to go to a big nursery or mail order.