black rot on grapes
It’s a sad story, a bad tale to tell, a tale of woe, weeping, and gnashing of teeth. It’s the tale of the sick grapes and the bad tomatoes and… it’s happening in my garden. Still, I think I’ll survive. But thank goodness I’m not depending on the produce of my garden to feed myself.
It’s hard to believe that just one week ago I was making your mouth water with my photo of beautiful, growing, green grapes on my garden vine. What happened? The short answer is that my grapes have black rot, caused by the fungus Guignardia bidwellii. Had I known what to look for I’d have figured this out several weeks ago, while the fruit was still good, because the leaves of my grape vine had telltale spots. As it is, it’s really too late to do anything at this point. Fungi thrive in hot, wet weather and black rot is apparently endemic east of the Rocky Mountains. Now I know that it wasn’t the squirrels which ate my grapes last year, it was the black rot that got them… sounds like something from a pirate movie. Obviously I wasn’t paying attention last year. Back then I suppose I had a brown thumb.
Then there are the bad tomatoes. Fortunately they’re really not too bad – only a couple of them are affected. I guess the problem is called blossom end rot. This time it is not caused by a fungus, but seems to be due to variations in water availability and cold, or excessively hot, weather during fruit set. The temperature and water fluctuations cause calcium to be unavailable to the developing fruit. It’s too bad the fruits from my garden aren’t likely to be any more perfect than my lettuce this spring, or my spring greens last fall.
I’ve got my answers, I’ve learned my lessons. Grape vines need good air circulation – there’s a reason people have those terribly organized vineyards. I’ll have to decide if I will keep the grape vine and spray it next year, or if I will let it go and plant something else. And tomatoes need mulching and regular watering, even when they are not wilting. Next year I’ll mulch them when they are small – I’m not sure I could get in to mulch them now. I’m keeping a good eye on them though and I’ll water them before it seems necessary.
In case you need to look these up:
- More about black rot from University of Illinois extension office.
- More about blossom end rot from Ohio State University extension.
How is your garden growing? Do you get frustrated by setbacks like this? Have you had any of these problems? How long has it taken you to master gardening?
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Congratulations on the new site, Alison – it looks fantastic!!
As far as grape-growing problems go, when I still lived in CA I had a grape vine growing outside the kitchen window…we didn’t have any problems with rot, but an entire family of raccoons completely destroyed the vine every year without fail! In a one-night binge, they would eat all of the grapes and pull down the vines & the trellis on the side of our house (which they used as a ladder!) in the process.
And I think you must be right about the tomatoes – my Italian Grandpa was obsessed with his tomato plants, and I remember him watering them constantly. And he kept them in raised beds; not sure what he did in terms of mulch.
I am counting the days (60!!) until we move into our new house, and I can’t wait to start planning a garden
Hey Laura, thanks for visiting and for the positive feedback. That’s a good story about the raccoons. I enjoyed reading it
I’m trying to be more regular now with the tomato watering. Today I see a couple of the larger tomatoes which aren’t quite as green. Maybe it will be less than a week until I have a juicy tomato to harvest.
Have fun dreaming about, and planning, your garden.
Alison