Hi, can you tell me why my broccoli heads are yellowish coloured right from when they start forming a head until ready to pick. I've never had this problem until this year. They have grown good healthy plants it's just the heads.

Hi Sue, broccoli is a gross feeder and requires high doses of nitrogen to stay green and healthy. Has organic matter such as compost, sheep pellets, blood and bone been dug in to replenish the soil after the previous crop? 

Also, it pays to rotate crops and not grow the same crop in the same place each season. Where the cabbages or cauliflower have been plant lettuce or spinach the following season to prevent disease common to those crops spreading.

Apply a nitrogen rich fertiliser, preferably a liquid now such Tui Seaweed & Fish fertiliser as this is instant feeding for the broccoli. Make sure you are replacing the nutrients that are being taken out after each crop.