Brassica respond well to Boron in the soil, but deficiency symptoms usually appear too late for remediation, so it is important that there is adequate supply at the early stages. Boron deficiencies are more common on sandy soils with a higher pH than 7. The symptoms vary across the brassica species, but the following is common across all crops; Curling of leaves with brittle margins Cracked and corky stems, petioles and midribs Hollow stems Interveinal (between the veins) chlorosis on old leaves ‘Brown heart’