Brassicas rise to the challenge on Welsh hill farm 

Wanting to be more self-sufficient, Welsh sheep farmer Rob Powell sought a cost-effective winter forage source. Since turning to brassicas, he’s also found environmental benefits and has even begun growing a new variety. 

This autumn, Germinal forage expert Harley Brown-Keech visited Rob to see how brassicas are playing a key role in reducing winter feed costs for his flock of in-lamb ewes. Several learnings stood out that other sheep farmers can benefit from. 

Rob has grown brassicas for more than three decades across his two holdings near Builth Wells, Powys. Over time, he has refined a system that supports 283 hectares (700 acres) and 2,700 ewes alongside his wife, Tracy, and their sons, Alun and Aron. 

The ewes are a mix of Aberfield crosses that are mated to a Texel, alongside Epynt Hardy ewes that are put to Aberfields to breed flock replacements. 

They lamb mainly outdoors each year from 25th March, with finished lambs sold at Builth’s livestock market. Lambs are creep-fed from six weeks of age, but ewes receive no supplement all year. 

How Rob gets establishment right 

For anyone considering growing brassicas for the first time, Rob’s advice is clear: “Don’t cut corners. Fertility grows a good crop. Soil test and give the land what it needs. Spending more at the start pays dividends later.”  

• Before drilling, fields are soil tested to ensure nutrients are applied accurately. A soil pH of 6.3 is targeted with a K index of 3 and P of 2.   

• Typically, grass fields are burnt off. Chicken muck from the family’s 90,000-bird boiler unit is applied at 3.7-5t/ha (1.5-2t/acre), depending on soil analysis results. 

• Then the crop is direct drilled at 1.9kg/ha (0.75kg/acre) before being rolled to achieve good soil-to-seed contact. 

Cost-effective winter feeding 

Rob grows 16ha (40 acres) of swedes alongside 8ha (20 acres) of fodder beet. After trialling different varieties over the years, Rob keeps coming back to Triumph.  

“We like Triumph. It has great get-up-and-go, which is vital to get ahead of pests. They are the best swedes we have tried. 

“The ewes do really well on swedes, and I believe growing brassicas is the cheapest way I can keep ewes throughout the winter.” 

He calculates it costs £345/ha (£140/acre) to grow brassicas: “I can keep 500 ewes on 10 acres, which costs me £1,400 to grow. If I had 500 ewes on tack at £1/head, it would cost me £6,000 for 12 weeks.” 

Advice: Transitioning sheep to grazing brassicas 

Sheep are gradually transitioned onto the crop at night and go back to grass during the day. Harley stresses that transition is key to rumen health: “Brassicas are high in sugar and low in fibre, so sheep must be introduced over 7-10 days.”  

• Follow the 70:30 rule – where 70% of the diet comprises brassica and 30% fibre (such as hay, straw or silage) – to slow digestion and prevent acidosis.   

• You also need a run-back area. It doesn’t need to be huge – a headland will suffice – but animals need a dry place to lie. 

• For optimal utilisation (80-95%), Harley advises long, narrow breaks across the feed face and strip-grazing, ideally with a double fence, or block grazing.  

“It’s the best way to use the whole plant, including the stem, which contains valuable energy and fibre,” Harley explains. “Double fencing is a good idea as a safety net in case the first wire fails.”  

Sustainable performance 

While highly cost-effective, the benefits go beyond the bottom line for Rob: “It’s about being self-sufficient, and it increases the soil organic matter, which improves soil water retention. 

“Plus, with disease risks like Bluetongue, farming at home makes sense. It’s a win-win for the environment, sheep health, and profitability.” 

Resilient Redstart 

In July 2025, Rob increased his use of brassicas by planting 2.5ha (6 acres) of Redstart. As a hybrid, Redstart combines the fast growth of rape with the digestibility and cold tolerance of kale, making it a highly effective winter forage crop for Rob. 

Sown in dry conditions, Rob was impressed at how strongly Redstart yielded after rain returned. This has shown him Redstart’s potential to produce forage in drought periods. 

“Looking ahead, I can see Redstart fitting really well into our system,” he says. “If summers stay dry, I’d plant it in May to provide feed for weaned lambs in July.” 

Breaking the cycle 

Beyond their feed value, Rob says brassicas act as a valuable break crop for grass.  

“Brassicas help break the disease cycle, and I’m getting a good crop of grass very cheaply because we don’t need any fertiliser before sowing.” 

About 20ha (50 acres) is reseeded annually using either a three-year red clover and grass mixture or a long-term dual-purpose mix. This contains Aber High Sugar Grass late-heading tetraploid and diploid varieties with white clover. 

Get the brassica boost 

From variety options to establishment, we’ve got you covered: 

If you want to know which brassica options we offer, click here. 

Want to know more about establishing brassicas? View our brassica management guide. 

Need to talk it all through? Find your nearest Germinal expert here.