{"id":1669,"date":"2012-04-23T12:32:38","date_gmt":"2012-04-23T12:32:38","guid":{"rendered":"http:\/\/www.my-grape-vine.com\/blog\/?p=1669"},"modified":"2012-09-22T05:44:42","modified_gmt":"2012-09-22T05:44:42","slug":"spring-frost-damage-on-grapes","status":"publish","type":"post","link":"http:\/\/www.my-grape-vine.com\/blog\/spring-frost-damage-on-grapes\/","title":{"rendered":"Spring Frost Damage On Grapes"},"content":{"rendered":"

Spring frost damage is a common problem among grape growers!<\/p>\n

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\"spring<\/a>As you can see from the picture on the left, spring frost damage<\/strong> on grapes can cause severe damage and if you grow your grapes in colder climates, you will sooner or later have to deal with\u00a0spring frost damage<\/em>.<\/p>\n

What makes\u00a0spring frost damage<\/span> a big problem is that preventing it, is not easy – economically and practically. \u00a0Some years you will have no\u00a0spring frost damage and another year you can loose all your grapes due to\u00a0spring frost damage.<\/p>\n

Even here in South Africa, where temperatures are known to be mild to hot, we sometimes face dangerous Spring temperatures and many grape growers in the lower\u00a0region\u00a0of where I live, have suffered crop losses because of\u00a0spring frost damage.<\/p>\n

Most grape growers from the US who grow their grapes in climates colder than zone 6, will\u00a0definitely know what I’m\u00a0referring\u00a0to.<\/p>\n

When will spring frost damage occur on grapes?<\/span><\/h3>\n

Generally, there are two type of spring frost. \u00a0Advective and radiattion frost.<\/p>\n

Radiation frost damage happens with clear night skies and calm airflow or wind conditions. \u00a0With clear skies, radiant heat from the earth moves up into the upper layers of the atmosphere and the calm wind conditions allow the air to mix. \u00a0An inversion occurs where the a layer of cold air is trapped below the layer of hot air from the dadiation.<\/p>\n

Advective frost happens when a cold front moves into an area with gusty winds trapping the cold air on at ground leve.<\/p>\n

Spring frost damage<\/a> – what\u00a0happens\u00a0inside the grape vine?<\/h3>\n

I will not dig too deep into the physiology of the grape vine, but\u00a0spring frost damage occurs when the water inside the plant cells of the grape vine cools down to temperatures below freezing. \u00a0Ice crystals form and damage the cell membrane of the plant cells, causing the sap flow to escape from the plant cells once the temperatures increase.<\/p>\n

Choosing your site to prevent spring frost damage:<\/h3>\n

The most important factor that will influence\u00a0spring frost damage is your site location – not even planting the correct variety, or using the correct pruning methods will fully safeguard your grape vines from\u00a0spring frost damage.<\/p>\n

Cold air is heavier than hot air and will form pockets of cold air in valleys, near rivers and even alongside a tree lines. \u00a0Avoid planting your grape vines on these location as far as possible; especially if\u00a0spring frost damage is a problem in your area.<\/p>\n

Planting your grape vines on a down slope, will force the cold air to move away from your grape vines, into the lower areas of the land – this could help prevent\u00a0spring frost damage!.<\/p>\n

Trellis & training systems to help prevent\u00a0spring frost damage<\/h3>\n

As said earlier, cold air is heavier than hot air, so the temperature close the surface of the ground is colder than a few feet higher. \u00a0Using a higher trellis system could make the difference between light and severe frost damage.<\/p>\n

Cultivation practices to help prevent\u00a0spring frost damage<\/h3>\n

Here are a few tips that might just save your grape crop from\u00a0spring frost damage.<\/p>\n