Scotsdale Garden Centre has a £5 money-off voucher for trees over £20 from 1-24 December through Beautiful Gardens magazine that goes out to four million addresses.
Managing director Caroline Owen said: "We offered free local delivery last year because we were worried about the economy and it is hard to take that away. Prices are the same as last year although there have been slight increases in prices to us on some sizes."
Meanwhile, Abercorn Garden Centre has sent a £5 off offer to its 7,000 email list.
Alton Garden Centre director Andy Bunker, who buys 40,000 Christmas trees for the Tillington Group annually, said: "They arrived quite early this year and we expect to sell about the same as last year.
"We're paying £23-£25 for a six-foot tree and they are rarely more than six feet now. We sold 2,500 trees five years ago but expect to sell 1,500 this year." He added that prices for bigger trees were "frightening".
British Christmas Tree Growers Association secretary Roger Hay said: "Wholesale prices have gone up because of fuel costs and VAT rises but I'm hoping that most growers will be sensible.
"But there may be a more noticeable increase in prices of trees over 2.5m high because of a shortage. Last year, people were inclined to cut more trees to meet market demand so they have not been left to grow."
He added that prices generally were £1-2 more at the wholesale end. "We're estimating sales of eight million fresh trees, about the same as 2010. Imports are quite small because the Danish kroner and euro are 20 per cent worse than last year."
Supplier Needlefresh managing director Chris Hood said: "There's an inherent lack of volume in the market at the supply end and the dry spring weather has meant that trees have not grown as much as anticipated.
"Prices are up five per cent on average, or more for larger sizes, but there's great angst at both supply and retail level about putting prices up any higher although diesel is up, fertiliser is astronomical and labour is more expensive."
He added: "The signs indicate a tree shortage. Everyone is importing from Ireland, Denmark, Germany, France or Belgium."
Real Christmas Trees owner Graham Gilbert said: "Large trees are permanently in short supply with growers as well as retailers."