(Bloomberg) -- Tesco Plc has joined discounter Aldi in limiting purchases of some fruit and vegetables in the UK after difficult harvests due to cold weather in southern Spain and north Africa.

Both retailers are capping purchases of peppers, cucumbers and tomatoes to three units per person. The moves follow Morrisons which has a limit of two products and Asda with a restriction of three.

The British Retail Consortium expects the disruption to last for a few weeks as supermarkets manage the supply chain issues. Shoppers in the UK have been posting pictures on social media of empty shelves in vegetable aisles across multiple supermarkets.

Read More: Asda Rations Sales of Fruit and Vegetables After Shortages

Grocers depend more on imports around this time of year, particularly from sunnier places such as Spain. Domestic production normally only starts in late March or April and supplies have been hit by labor shortages and the higher cost of energy and fertilizer.

Asda, the UK’s third-largest supermarket, was first to introduce restrictions this week, with limits across tomatoes, peppers, cucumbers, lettuce, salad bags, broccoli, cauliflower and raspberries. Morrisons’ cap applies to tomatoes, cucumbers, lettuce and peppers.

Colder weather than usual in Spain and northern Africa has led to produce growing more slowly than usual and prevented it from ripening. Almost every retailer in the UK sources from these warmer regions.

In the Spanish region of Almeria, production of tomatoes, peppers and cucumbers fell by more than 20% in the first two weeks of February, according to Fepex, Spain’s federation of fruit and veg exporters. A warm start to winter followed by a cold snap has hampered growing.

In the UK some farmers using greenhouses to grow salad vegetables have lowered heating to save on expensive energy bills, leading to less output. 

Brexit

Some shoppers are contrasting shortages in the UK with full shelves elsewhere in Europe, raising the question of whether Brexit has a role to play in the lack of availability. Agricultural greenhouses in the UK have been “hurt horribly” by Brexit, Justin King, former CEO of J Sainsbury Plc, told LBC radio.

Still, Irish stores are also seeing shortages stemming from Spain and north Africa and retailers are looking at alternative sources of supply, according to Retail Ireland.

Meanwhile, UK retail trade union Usdaw is appealing to shoppers to go easy on checkout staff who have to enforce rationing across products. 

“Retail workers aren’t responsible for setting limits on what customers can purchase,” Usdaw tweeted. “It’s never acceptable to take out your frustrations on shop staff.”

--With assistance from Olivia Fletcher and Megan Durisin.

(Updates with Tesco from first paragraph, more details from seventh.)

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