What are Companion Crops?

Companion crops are those that are grown alongside the cash crop to serve a purpose, but which are not taken through to harvest. They are common in horticulture (nurse crops), but have recently been introduced to agriculture to try to help with insect pressure.

Since the ban on neonicotinoid seed treatments for OSR this crop has become increasingly difficult to grow as cabbage stem flea beetle feed on the crop when it is establishing, often destroying the crop early. Where the crop survives and makes it to the spring, their larvae can cause damage, or destroy the crop before harvest. At Brixworth Farming we have not planted this crop for three years and have not harvested it for 4!

How we have used Companion Crops (2023)

This year we have grown OSR at two our of blocks, which were planted with companion crops (Buckwheat and Clover). These were chosen to try and help protect the OSR plants from flea beetle (although the benefits are not proven, there are very little options available!). They were also chosen to help fix nitrogen and make it available to the establishing OSR crop (clover) and to mobilise insoluble phosphate in the soil making it more accessible to the crop (Buckwheat).

These plants were taken out by either the frosts in December, or through chemical control later in the year, so they do not become an issue later on and do not set seed and become weeds for the following crops.

Establishment has been reasonable this year, although it did struggle on the heavy soils due to the lack of rainfall in summer. There was some flea beetle damage in the autumn, but it was not significant, and there has been some larval damage this spring (some of the areas that were slow to come into flower). Where the larvae got into the stem behind the growing points, this, in conjunction with the frosts in December and January, have killed some of the plants. Thankfully, this has resulted in just a crop thinning, however some parts of the country have seen complete crop loss because of this.