By now the vineyards will be greening and growers on the watch for frosts that could kill the tender shoots.
Because of the flourish of planting in the late 1990s, many of the Cromwell basin vineyards are now about 15 years old, and beginning to show maturity, Northburn general manager Paul Tudgay says.
As vines age they tend to produce more intense wines that are tighter when young and benefit from a couple of years of bottle age before release.
That is certainly true of the wines I tasted on this trip.
Northburn vineyard is on Northburn Station, on the northern side of Lake Dunstan, and is known for its fine merino wool.
Its wines are characteristically spicy with a hint of mineral.
Tom Pinckney, who, with his wife Jan, owns the station, says they always had a vision of their own brand of wine as they were in a wine-growing and tourist region and they planted the first grapes in 1999.
However, they also wanted more than just a cellar door, and with Jan's background as a chef and caterer, they also planned The Shed, built from recycled timber from the farm which houses a cellar door, restaurant and function centre.
Northburn's first vintage was 2003, and the pinot noir from that year is fully mature, silky and still with complexity and charm.
Northburn's first riesling from the Jewellers Shop block (named after a mining claim) was made in 2007 and is delicious now, rich and mouthfilling with a hint of mineral and honey.
The 2010 in comparison is youthful, tight and delicate with a hint of lime and marmalade and promises to develop with more bottle age.
They also make a serious rosé: well structured, dry and refreshing, just the thing to accompany lunch in the vineyard.
• Mark Weldon and Sarah Eliott bought the former Olssens vineyard, one of the oldest in Bannockburn, a couple of years ago and have since bought two nearby vineyards.
Terra is close to the river, below the original vineyard, and Diggings on the hill on the Cairnmuir side of Bannockburn from which its good value Mysterious Diggings pinot noir comes.
Last year, they built their own winery on the Sancta block, part of their plan to focus on their sites and the interconnections between the wines, the vineyards and their individual blocks and the people who work there.
These are beginning to emerge as the owners, the vineyard team and winemaker Jen Parr get into their stride.
It will be interesting to follow the progress of these dedicated new owners over the next few years.
Two different rieslings, planted in adjoining blocks, have produced quite different wines.
The Miro's Block dry 2012 is silky and lively with a dry finish, and the Slapjack 2012 is sweeter with lovely fruit and a steely shaft of acidity.
The two wines that most impressed me on this visit were the fine, complex but restrained River Block chardonnay 2012 and the perfumed, gamey Shingle Beach pinot noir 2012 which won't be released for some time yet.
For summer drinking there's a bright fresh rosé with more substance than many, a Mysterious Diggings pinot gris 2012 oozing pears and nectarines, and the good value charming, perfumed Mysterious Diggings pinot noir 2012 with dark fruits and a hint of earthiness.
• When Graeme and Gillian Crosby of Domain Road planted their vineyard in 2002 there were only a couple of other houses in the Bannockburn street, but now it's looking almost suburban.
In addition to the original vineyard in a former orchard next door to the Bannockburn camping ground, they have recently planted a 10ha vineyard, Defiance, off Felton Rd.
It looks like a hot little basin near some of Mt Difficulty's vineyards so it will be interesting to see the wines that come from there.
Besides its dark, spicy pinot noir, which has impressed from its first vintage, and their concentrated, tightly structured premium Paradise pinot noir 2009, Domain Road produces some stylish whites.
I tasted the 2008 riesling from their first harvest, a limey, oily, wine with a steely backbone that is drinking well now.
The 2008 sauvignon blanc has developed deliciously and is crisp with hints of peas and gooseberries.
• Warwick and Jenny Hawker planted their Black Poplar vineyard on the Pisa flats on the Wanaka road nearly 20 years ago and live in a converted woolshed on the site.
Their silky Black Poplar pinot noir is intense and complex and has built a fine reputation for itself, but the more affordable, attractive Pisa Range Run 245 2011 (named after the pastoral lease number for the original Kawarau Station) is very drinkable, being red-fruited with savoury undertones.
Recently they released their first light zesty riesling (2012) from vines planted about eight years ago.
It appears dry and she recommends it with curries.
