We have had several enquiries asking how to control annual weeds in new sown leys this spring, especially in herbal leys or multi-species swards where herbicides are not an option.

The dry weather this spring and early summer has led to perfect conditions for strong flushes of spring germinating annual weeds popping up in new leys. Quick growing, aggressive species like Fat Hen (Dung weed), Redshank and Charlock have grown strongly in the absence of competition from reseeds that are struggling to establish quickly due to a lack of moisture. These aggressive weeds will make use of open areas and bare ground, with the aim to flower and set seed quickly to ensure survival and another flush of weeds later in the year.

The good news is that these annual weeds can be controlled with some well timed topping or flailing. While a rotary topper will do the job, it can leave excess biomass in lumps which can smother some of the struggling sown seedlings. A flail mower is preferred because this will shred the weeds and tends to spread the biomass in a more even and lighter covering.

If the weed cover is particularly dense (see photos below) consider flailing once at knee height to avoid a big build up of biomass, leave the field for a week or so and then flail down to 'welly toe height' to remove the rest of the weed pressure. Aim to carry out any flailing operations in dry conditions and once the morning dew has dried off, to help the biomass become brittle and spread more easily.

If some of the sown seedlings have been baked out and lost during the recent hot weather, the new ley may need to be assessed in early autumn and either topped up or possibly resown.

However the management mentioned above in the first 6-10 weeks of the new ley can in many cases transform what looks like a messy disaster, into a successful reseed by the autumn, despite the challenging conditions.