Hollow stem, a condition of cabbage, cauliflower, and broccoli, may occur during very rapid growth. On affected plants the interior pith tissue of the stem or head is collapsed or cracked and often hollow. Usually the head or stem must be cut open to see the damage.
Solutions
High temperatures, in combination with high levels of nitrogen and large stem diameters, are associated with the disorder. Wide spacing of plants may also contribute to the problem. Plants deficient in boron may exhibit symptoms, but when boron deficiency is involved, the interior of the cracked stem cavity is darkened. Keeping nutrients at recommended levels and avoiding excessive rates of growth help prevent hollow stem.
