Answer: Raspberries are brambles and, whether you consider it a blessing or a curse, the roots tend to colonize an area pretty quickly. Aside from digging the plants every 3-4 years and then replanting only a few, you may be able to contain the roots in the same way running bamboo roots are contained - fiberglass or galvanized roofing panels set on their sides in a deep trench. These panels are relatively inexpensive and available at home improvement centers (look for them in the patio roofing section). They come in 6 to 12 foot lengths and 24-inch widths. I'd set them about 3 feet away from the berry plants to give the roots adequate room to grow. Best wishes with your berry harvest!
Q&A Library Searching Tips