For the second year in a row, I’ve unsuccessfully tried to grow courgettes. They grow to about 5cms in length then the base of it burgeons out into a large bulb shape, then the remaining thin part of the courgette turns bright yellow. What am I doing wrong?
Sorry to hear you are having trouble with your courgettes, it can be frustrating when it happens over a few seasons. There could be a few reasons for the problem. Courgettes prefer a hot, sunny, reasonably dry position in the garden; with moist, free draining soil. If your soil is water logged you may need to add in more compost or a vegetable mix to help with drainage. Prior to planting it can also be beneficial to mound the soil slightly to reduce the possibility of the plant getting too wet via rain or irrigation.
Another potential cause is that you could be overwatering your plant. This can cause discolouration and development of fruit and also encourage blossom end rot, which can cause the fruit to yellow and rot on the plant. It is better that a courgette is on the dry side rather than excessively wet. But of course don’t let the plant dry out.
Excessive fertiliser can also lead to large leaf growth, misshapen fruit and limited or no courgettes. Courgettes are comparatively low nutrient loving plants and so long as the soil has been prepared well before planting, they should grow well. You can apply fertiliser once the fruit starts to form fruit and water it in well.