Raspberries need well-draining rich soil that is kept moist, but not wet, and full sun for 6-8 hours. If there is any shade, it is best in the afternoon. An ideal pH for raspberries is 6.0, which is a little on the acid side. Coffee grounds add acid to soil for raspberries and blueberries. Fertilizer burn can manifest in brown, crispy edges of leaves. If your plant leaves have brown edges this means the plant may be stressed. This stress can be from a number of factors, but the most common are: too little or too much water, too much fertilizer, or attack from an unseen enemy (aphids, borers, blights, viruses). Usually, though, it's an easy fix. You might also try mulching the soil surface.