Asparagus ‘Erasmus’ (Purple asparagus) is best planted in sandy soil, before planting you should loosen the soil well and sprinkle some fertilizer in the hole. If the asparagus is above the ground, you do not need to cover the outlets with soil to harvest the green asparagus. You can harvest the asparagus in May and June. Stop harvesting at the end of June otherwise the plant will weaken too much and not come back enough the following year. It is also important to remove the yellow foliage in the fall.