All grass and weeds should be removed prior to planting. This process limits competition which can result in high plant loss. If the area is covered with vegetation two applications of a broad range herbicide is recommended for eradication. An additional measure to guarantee a weed-free bed is sterilization of the soil with a fumigant. If a sterilant is to be used, extreme care should be taken.
Amending the soil is not always necessary. In a very heavy clay soil, one option might be to till in a sandy loam topsoil and/or sand to help increase aeration. For a lighter soil that is lacking in organic material, peat moss can be incorporated.
A low nitrogen or balanced fertilizer can be incorporated into the root zone, to help promote rooting. Slow-release fertilizers can also be used, but at reduced rates when incorporated into the soil.