Grapes buds are not growing

Asked June 11, 2018, 9:03 AM EDT

I have 5 year old grape vines that are budded (green buds) and have started to swell and just stopped. I should have several feet of growth by now. What is happening?

Hillsdale County Michigan grapes grape diseases frost damage

1 Response

You do not say what type of grape you have. The green buds in the picture are tertiary buds which develop when the primary and secondary buds are killed. these develop at the base of shoots and areas around the dead buds.
This can result from winter cold or spring freezes after the buds start to grow.
Your area got down below -10 F on December 28
and January 6
Those temperatures are cold enough to hurt European wine grapes but most hybrids and lumbrusca grapes can go down to -20.
I have seldom seen those temperatures kill all the buds on a vine.
If you did not see damage after the 'Polar Vortex' years of 2014 and 2015 , I doubt winter injury was the cause. Are you seeing a lot of growth from the base of the plant..
There are some insect pest which attack the buds as they are swollen
Grape flea beetle
climbing cut worm
These too seldom kill all the buds so you should have had some growing shoots.
The long cool spring could have kept the buds swollen and susceptible to cutworm damage.
The last possibility is a spring freeze. Grapes are very susceptible to freeze injury in the swollen bud stage and during early shoot growth.
Looking at the weather it looks like May 8 is a likely culprit. The temperatures got down to about 25. I have seen almost total losses in grape vineyards that get down to 25 during late swell or bud burst.
You say the buds started to grow and then turned brown and stopped growing. This sounds like a spring freeze to me and I have seen many.
Typically the vine looks dead and then about a month later you see new buds pushing. These shoots will grow but the buds with flowers were killed so there will be no fruit this year but the vine will recover.