He said the economic climate "might make it difficult for some people to buy trees", but added that it was still unlikely there would be enough trees available.
Hay said it would be three or four years before supply met demand after a lack of planting around five years ago.
He added that more potted trees were now available, with consumers keen to be seen as environmentally friendly by planting them outside after Christmas.
Dumfries-based Glaisters Farm owner Sally Young said: "We have never got enough for sale. We wish we had a few more.
"We plant one-and-a-half or two trees for every cut tree we sell, but it is the green thing to buy a potted and not a cut tree."