Walnut trees (Juglans regia) are a good choice as tree species in agroforestry systems in Flanders (Belgium) because of their ecological characteristics. Moreover, walnuts are gaining popularity fast among consumers making it a promising business. That is why recently there has been a relatively strong increase in the number of walnut plantations in Flanders. However, to maximize profit and get the most out of your system, it is important to think in advance on what products you will put on the market and how. You can increase profi tability by valorizing as many parts of the tree as possible and processing waste products where possible. When planting walnut trees in an agroforestry system the choice is usually made to produce eithertimber or nuts. Although it is more complex in terms of profitability, a combination of both goals is possible with certain varieties (for example Coenen) or by planting seedlings (usually faster growing). Nevertheless, there are also a lot of innovative business models ...