As promised, some exciting news from the vineyard this week…
At Kim Anderson’s vineyard in Charleston spring has well and truly sprung – despite the fact that it still feels like winter to me! And as I found out from Kim last week, I’m not the only one who has been feeling the cold.
Spring arrives in the vineyard
Budburst occurred in the Pinot Noir on the 22nd September with all other varieties following quickly.
What is budburst?
Bud burst refers to the period in early spring during which grapevines emerge from dormancy to produce new shoots. Small buds on the vine will now give rise to leaves and flowers. Bud burst is brought about by changes in the air and soil temperature
During the bud burst phase, the vines are quite susceptible to frost damage. This makes it a particularly delicate time during the process of cultivating grapevines.
So, you can probably guess what happened next…
And not just once…
The vineyard has been hit with four frost events since then! The last one was the worst in Kim’s recorded history – it lasted from 9.10 pm at night until 7.30 the next morning.
Luckily Kim uses a frost sprinkler system. He has a weather station near the dam beside the frost system computer which starts the sprinklers when the temperature drops. That dam contains a large volume of water which holds a lot of heat. Still, the temperature got as low as -3 degrees there during the worst of it.
The frost extended up and over the hill behind the vineyard, which is highly unusual for this vineyard. So much so that Kim doesn’t have sprinklers on the higher ground. All the vines being sprinkled on the lower part of the vineyard were saved from damage. The photo above is taken from the top of his Sauvignon Blanc and shows the sprinklers working beautifully. Unfortunately, the unprotected higher part (about one-third of the total) was badly burnt. It will be a nervous wait for Kim over the next few weeks to see what recovers.
Hang on, why on earth would you water during a frost??
Cold air around newly formed buds on the vine is one of the biggest concerns for a vineyard manager. If the temperature drops below zero degrees Celsius, as it does during a frost, the vines essentially get frostbite. The sap within the bud freezes and causes cells within the bud to burst. They look as if they have been burnt. It destroys the new shoot and the tiny bunches of grapes within.
The idea behind using sprinklers during a frost is that the water absorbs the cold air around the vine and protects the newly formed buds. The frozen water around the vine is actually “warmer” than the air. The ice protects the buds from the colder air.
Check out the “ice igloos” around the individual buds in the photo from Kim’s vineyard. This will protect the buds as long as the sprinklers run through the duration of the frost, plus the hour after sunrise (when the frost is at its worst).
Other ways to protect against frost
Other than having his frost sprinklers in place (and working properly!), Kim would have been preparing for potential frosts by doing a couple of other things…
- Fact: moist soil tends to stay warmer than dry soil. A regular watering schedule, particularly in dry, cold weather can help protect the vines from freezing temperatures.
- Good weed management practices ensure that cold air is kept down low at ground level. If long weeds are left to grow around the base of the vines, then the cold air will sit up around the top of the weeds which is closer to the buds. Have a look at the first photo again – Kim is doing a beautiful job of his weed control.
So, what now?
The buds in Kim’s vineyard which have been damaged are lost. Luckily though, it is still relatively early in the season. The vine has the ability to reshoot from the second and third buds at each node. The vine will still produce fruit, but the yield will be lower as those secondary and tertiary shoots are less fruitful. Fingers crossed he won’t be too badly affected.
Damage like this can upset the vine balance due to the lower bunch numbers. Kim will have to do a lot more canopy management than usual. With fewer bunches, there will be more vegetative growth which will need to be trimmed back to allow sunlight to reach the bunches that do form.
Are you interstate and disappointed you miss out on all our wonderful events? How would you like to have Rob, in your home, taking you through your own personal tasting? Well, that’s exactly what we’re planning to bring you with our new virtual wine tastings!
Here is a sneak peek at a draft version we did for one of our lovely Sydney based Jockey Club members. He was desperate to be a part of Rob’s sell-our Vertical Shiraz tastings last weekend, so we made it happen for him!
Would you like a virtual visit from Rob? Do you have a collection of Somerled wines in your cellar that you’d love to show your closest family/friends with some wise words from the master himself to accompany them?
Tell us what your version of an at-home tasting with Rob would look like and we could make it happen for you too!