Plant and flower imports are rising while exports are falling, according to the latest Defra figures.
The annual Agriculture in the UK plants and flowers update was published by HMRC last month. It shows that exports fell to £56m in 2014 from £61m in 2013.
Imports rose to £1,106m from £1,079m. Cut flowers were among the highest risers, up from £663m to £691m, despite campaigns for retailers to sell more British-grown bouquets.
But tree imports fell from £62m to £51m after cuts in grants for woodland planting. In 1995, tree imports were £6m and cut flowers £256m.
Bulb imports peaked at £95m in 2011 but reached £82m in 2014 under provisional Defra figures.
Defra works with ADAS to collect data on production areas, which have remained steady at around 12,000ha for several years, although were as high as 20,000ha 20 years ago.
The value of production fell slightly from £1,191m to £1,166m, which is still the second highest total ever, having broken through the £1,000m mark in 2011.
The 2014 figure is split into £42m flowers and bulbs in the open, £796m hardy plants and flowers nursery stock and £328m protected crops - all of which showed marginal falls.
HTA chief executive Carol Paris said: "With the strength of the pound the cost of plants from the continent is attractive. Tree imports being down is more to do with forestry grants."
Cut flowers Call issued for more growers
The Scottish branch of UK cut flower grower network Flowers From the Farm (FFTF) has called for more local growers to come forward to meet the demand from Scottish customers for homegrown bouquets.
Paula Baxter from Mill Pond Flower Farm in Foulden, Berwickshire, said there are just 12 Scottish growers registered and "there is a big demand". She sold out of her cut flowers in 2014 and is growing 10 times more in 2015, with dahlias a big focus, she added.
Speaking at Gardening Scotland, Baxter said: "Florists now want to use British-grown."
Interflora was caught out using just one British variety out of 60 in its "quintessentially British" display at the RHS Chelsea Flower Show last month. "If they wanted to change to use more British flowers they could," said Baxter.
She added: "It's terrible because what they are saying is British-grown is not in season. It gives a false view of what is possible and what is available.
If these flowers are British then they should say they are and promote that."
Baxter described an increase in the value of cut flower imports from £663m in 2013 to £691m in 2014 as "disappointing", but added that buying of home-grown cut flowers is rising too.
FFTF will be exhibiting at the RHS Hampton Court Palace Flower Show on 30 June to 5 July.