The raspberry bed is a priority because the canes have a mass of roots just below the surface that thrive under a deep surface layer.
A mulch has several benefits. It helps retain soil moisture and a cool temperature in hot conditions, conserves warmth in winter, and suppresses weeds.
A range of materials, including heavy duty plastic sheets and bark chippings are used, but cow or horse manure that has been exposed to the elements over several months is ideal because it also offers nutrients.
A well-weathered organic manure is key to growing successful fruit and vegetables. Added to beds between late autumn and early spring, it keeps the soil rich in humus.
Where there are edible crops that swell, such as potatoes and courgettes, or soft and top fruits that demand copious amounts of water, humus is necessary. It is the sponge that absorbs and stores soil moisture, releasing it on demand.
If a vegetable patch fails to make much progress and there’s no obvious sign of pest or disease, you must consider whether the land is impoverished. When did it last receive organic matter or fertiliser?
It makes sense to replenish annually those elements used to produce a healthy crop.