Soil Preference

Soil PH: 6.0-7.0, Ideal 6.4-6.6

Leeks need a deep, rich, fairly neutral soil. It should be well drained, because the plants will remain in the ground through much of the winter and are susceptible to rot in wet soil. They do particularly well in deep intensive beds.

Leeks can be planted fairly early in the spring, so gardeners often prepare the growing bed the previous fall.

Soil Preparation

Compost (N), 2 inch(es), in top 6in of soil, 1 time

Incorporate 2˝ of compost or aged manure into the top 6˝. If the soil is compacted, you might want to consider double digging, because Leeks like loose loam. 

Standard Mix, 5 pound(s) per 100 sq. ft., in top 6in of soil, 1 time

Incorporate a standard mix into the top 6" of soil along with the compost. It will supply any additional nutrients required.