Spalding-based Butters already provides a series of products for Waitrose with 75 per cent of the flowers UK grown.
Butters Flowers, a division of the £52m company with a £12m turnover, is working with a grower in Boston to produce locally grown Tanacetum parthenium (a variety of chrysanthemum) to use in bouquets for Waitrose – a bloom which is normally imported from Holland.
Next year they hope to extend trials to extend the UK growing season for agapanthus so UK flowers can be used for a longer period of the year rather than relying on imports from Columbia or Kenya.
Both projects are being spearheaded by Butters technical manager Tracey Thomas – who has also been running trials for the Cut Flower Centre to help product development.
Business development manager Jo Pearson said: "The solution lies in retailers giving long-term commitments to selling UK flowers because without that growers cannot invest in their crops or their business.
"At Butters we are passionate about getting more products from UK sources on the shelves. Anything we can do to advance the UK growing sector we will. We want to work with growers to create new and alternative products and improve the quality.
"The support from Waitrose has been instrumental in helping us to do that. They are committed to selling UK flowers and that has helped enormously."
Products it distributes on behalf of Interflora, Flying Flowers and Moon Pig have 20 per cent UK sourced flowers on average – but the company accepts there is room for improvement.
Pearson said: "The concept of the Union Jack labelling is right but the execution needs to be stronger. The more we can do to promote the flag the better. We want to be waving it as proudly and as visibly as possible."
Butters Group clients include Moonpig, Interflora, M&S, Wilkinson, Tesco, Waitrose, The Co-operative, B&Q and Sainsbury’s. Butters Flowers processes nearly 3,500 bouquets a day and employs 70 staff.