It will supply organic manure, add nutrients and help to retain moisture in the soil. Borax 18 Iron sulphate 18 Copper sulphate 18 Zinc sulphate 16 Sodium molybdate 2 Double superphosphate is preferred to superphosphate as it contains less cadmium which is a toxic heavy metal. Bulbing starts six to eight weeks before harvest when the base of the stem is 1.5 times the diameter of the main stem and small cloves can be seen internally in cross-section. On fertile soils, garlic can be grown with much smaller applications of fertiliser. On alkaline soils, applications of extra trace elements may be necessary after planting and before bulbing.
Zinc deficiency is seen as a 'Z' bend in the newer leaves.
Manganese deficiency is seen as streaking of younger leaves and as leaf twisting around the stem axis. It is recommended that nutrient analyses are made of the soil and irrigation water before planting, plus one to two analyses of the youngest mature leaves after planting. This will enable some adjustments to the fertiliser program and provide information on nutrients that are deficient or toxic. Some of the suggested nutrients in the programs in this publication may be deleted or reduced, if it is obvious that they are sufficiently high in the irrigation water and soil, including sources from compost and fertilisers from previous cropping. Do not apply excess fertilisers, because nitrogen, phosphorus and potassium are easily washed through sandy soils by rainfall and irrigation.