Usually, his cherry season finished in mid to late January.
Mr Jackson put the early season down to the hot weather Central Otago had in November.
The weather had been mostly dry and he was ''praying'' for no further rain until the end of the season.
''It's not so bad if you get a cold rain at night; they can survive that as long as they're dry in the morning, but it's these warm rains in the evening at 5 o'clock when the sun's out ... that do the damage.''
This early season had not impacted the demand for cherries, Mr Jackson said.
''Because it's Christmastime there's plenty of cherry eaters and, being early, we've started exporting earlier as well.''
The orchard exports about half its crop to countries such as China, Taiwan, Korea and Vietnam.
Finding enough cherry pickers had not been a problem for Jackson Orchards. In fact, it had to turn away some people seeking work, Mr Jackson said.
It employed about 50 casual staff.
''Because we're on a main road we seem to get the call here first; we've been a bit lucky that way.
''We say to them we're full but we believe there are other growers looking for staff ... we generally give them a map of where to go and try.''
Mr Jackson also said they had begun picking apricots this week, which they did not usually do until early January.
45 South chief executive and Summerfruit NZ chairman Tim Jones, of Cromwell, said his orchard produced a late variety of cherries and would be finished by January 25.
He expected the cherry crop would be up by about 20% from last season.
Jerry's Cherries owner Jered Tate, of Teviot Valley, said his varieties of cherries would keep him busy until early March.
''So far, so good,'' he said. ''On my watch, there are heavy crops all round.''
He expected the crop volume to be up from last year, but did not want to estimate a percentage.