Hi @Lisbeth1,
That appears to be a cherry laurel tree, which is a species that has an extremely dense and invasive root system. These roots spread well beyond the tree’s canopy and aggressively compete for both water and nutrients. When you till the soil and find it full of roots, that is a clear sign that the tree has colonised the bed. Vegetables, which are shallow-rooted and require rich, uncompeted soil, will often become stunted under these conditions. The fact that potatoes and onions grow reasonably well makes sense, as they are more tolerant of poor soil and competition than many other crops.
To make your patch more productive, you would need to exclude the tree roots from the growing area. This can be done by installing a Root Barrier sunk deep into the soil, or by constructing raised beds with solid bases or liners that prevent roots from entering. Alternatively, container growing can bypass the issue entirely.
You can improve the growth of your vegetables by adding nutrients in the form of composts and fertilisers and keeping up a regular watering schedule, but even with additional care, the tree will likely outcompete your crops unless some physical separation is created.
If the cherry laurel stays, you’ll have better success with tougher crops that tolerate root competition, such as potatoes, onions, garlic, leeks, carrots, beetroot, parsnips, kale, silverbeet (chard), perpetual spinach, and hardy herbs like rosemary, thyme, sage, oregano, and parsley; however, nutrient-hungry plants like tomatoes, cucumbers, zucchini, beans, and corn will likely fail unless grown in raised beds or containers where the tree roots can’t invade.
Let me know what you think, and if you have further questions, please don't hesitate to ask.
Jacob
