To harvest the plant you can right-click it. Left-clicking will harvest the plant as well as destroy it, leaving only crop sticks. Harvesting Coffee may yield Coffee Beans. Left-click harvesting can also produce Coffee Seed
Note: Since Aurelia and Ferru look identical to Coffee prior to the final stages of growth, it is advised to place Iron Ore and Gold Ore under the farmland instead of 4 dirt blocks to ensure maturity of the plant. Having both works so long as they are within 3 blocks.
When growing Coffee, an extreme amount of patience is needed. It is highly recommended to use a Crop-Matron filled with Weed-EX, Hydration Cells, and Fertilizer. It is important to note that excessive use of Weed-Ex will lower the crop's stats over time.