Wednesday, May 26, 2010

Yellowing leaves on grape vine

Recently I have noticed some yellowing in the leaves of one of our grape vines (the white one), as seen in the picture above.


We don't give our grape vines too much water, but on the Sabbatical year when there was no watering at all they produced beautiful grapes and I observed no yellowing of leaves or other symptoms of disease. So I don't think it's lack of water. Overall the local plants (olives, grapes, pomegranates) are very sturdy, suited to the dry climate and don't require a lot of water. 

I checked out this table of various deficiencies and their symptoms and it looks as though it might be potassium deficiency but I'm not sure. I mean, why just one vine and not the other? Does this have to do with the variety of the grape? Perhaps adding some compost might help? If someone out there is more experienced in growing grapes and has a bit of advice for us, we'll be grateful! 

I do hope it can be fixed - love our grape vines. I love living in a house surrounded by the lush greenery of their leaves. Some time ago, someone suggested I should cut the grapes down if I'm afraid of the wasps they attract, but I don't think I could do that. First, for Jews, cutting down a fruit tree is not a matter to be taken lightly - we would have to consult a rabbi. Second, I don't think I could give them up. They provide such lovely shade, not to mention the most delicious grapes I've ever tasted. So, again, advice is much appreciated. 

5 comments:

All things bright and beautiful... said...

If you think it's potassioum they need you could dig in some chopped banana skin into the surrounding soil - I use it as a potassium feed on some plants here in the uk. It decomposes quickly and so adds to the soil texture and nutrient value and will do no harm if it is not potassium that is required.

Morag said...

Anna,
First check to see that the yellowing leaves aren't on a stem that has been damaged somewhere along its length either by having been broken or scraped or insects. Look carefully for swellings in the stems, chewed or ragged leaves or globs of foam that indicate insects. If there's no damage and the yellowing spreads check the soil chemistry. Yellowing usually reflects a lack of iron or copper, sort of vegetative anemia. Take a yellowed leaf in to a local agricultural office or to a plant nursery to have them diagnose or to the library to go through a gardening book and see if any pictures of disease conditions match your leaf. You might need to spray for fire blight or rust, both contagious plant diseases.
Linda

messy bessy said...

Your grape vines may be different than the ones we have here in the midwest US, but ours only get healthier if you prune them down to the ground.

We bought a house about 80 years old, and the grape vine out back seems about that old too! We have TRIED to get rid of it, as it overwhelmed the narrow strip of dirt that is our only place for gardening, by cutting the entire thing down, leaving only the stump that was too large to cut out. Well, we had one summer of an orderly garden, but the next year the thing just exploded, and now we have given up trying to contain it. My husband built a skeletal canopy over the back gate and the thing is already covered with vines.

The only problem is that the grapes it produces are too bitter to eat, although abundant.

So if you did cut that particular vine back, it might actually do the thing good? (But I'm only speculating.)

Bless you!

Mrs. Taft said...

Do you guys have aphids there? Aside from the things mentioned already, aphids suck the 'sap' out of healthy leaves and cause them to yellow.

quinnr said...

Due to the age of this posting this topic may well be history by now. However, I have yellowing grape leaves, on grapes I've had for some several years, that until recently were very healthy. From my research I've learned that a Black Walnut tree in the vicinity can cause such yellowing and eventually death of the vine. I have a maturing American Black Walnut in the immediate area. It's roots, as I understand, are toxic to other plants. It's own defense to avoid sharing the nutrients of the soil in which it is planted. I think the walnut tree is going to have to go.