Our nursery is divided into 130 flower beds, each about 20 square meters, so crop rotation is no problem. This has the advantage that there is almost no need for extra fertilization, since each culture uses different nutrients in the soil, but it also returns different nutrients to the soil, in the same way green manure is used. We even consider "weeds" as green manure!
The liquid manure that we make is like a kind of "health-tea", full of minerals, vitamins etc. It helps plants become strong, which means they are more resistant to insect attacks and fungal diseases. We "brew" this tea, by putting stinging nettles, comphrey, horseradish and various weeds (all parts of the plants) in a container with water. After 5 - 7 days it is ready to use, in diluted form. We use it for our young seedlings, when they are still in their trays, and when they have just been planted in the open field.
We also use it, in combination with cow-manure pellets, for certain cultures which really need extra feeding. Some of these are Canterbury Bells, Sweet Rocket and the pumpkin family.
During the winter, we let the plants die off, forming a "blanket" over the land. We do not tidy up the flower beds, because all kinds of microscopic creatures do that for us, thereby keeping the important top soil very fertile. Any woody plant parts are chopped to smaller pieces, as they need a longer period to decompose on the compost heap.