What Causes Yellow Kale Leaves

I haven’t had the best of luck on my balcony garden. The oak greens were wiped out by cabbage worms and the purple kale had an aphid infestation.

Now the leaves on my kale containers are continuing to yellow. From what I’ve heard and read there a bunch of causes for the leaves of kale to yellow.

It could be a lack of nitrogen, so I added coffee grinds to help with the yellow leaves. That didn’t work.

I’ve also read that it could be because of poor drainage. I stopped watering them for a bit. That didn’t work.

Someone else said that it could be due to lack of watering. I watered more frequently. That didn’t work.

The most important thing is that kales are a decent size, so I am gonna harvest and eat them before the end of the week.

This is another reason that I don’t read many gardening books (except for “Grocery Gardening” ) and listen to the “experts” because there is no one right answer.

I’m sure there are a million other causes that people can think of for yellow kale leaves. What are they?

httpv://www.youtube.com/watch?v=DoQ06KH794c

Meemsnyc June 23, 2010 at 7:47 pm -

Hmm, that is frustrating!!
Fern @ Life on the Balcony June 23, 2010 at 11:18 pm -

The majority of the time yellow leaves means drought stress. My guess is that you either didn't water frequently enough, you didn't provide enough water when you watered, or temperatures on your balcony were too hot for the kale to be able to keep itself hydrated (water was evaporating off the leaves faster than the roots could draw up new water).

In general, it;s pretty hard to grow kale in the summer months in So Cal. It's usually a late fall to early spring vegetable here.
Mike Lieberman June 24, 2010 at 2:21 pm -

Thanks Fern. I'm gonna harvest and eat them soon. Not sure about the drought thing. I put my finger pretty deep in and the soil was moist. The reservoir container has also been continuously filled with water.

I think it could either be the insects or not enough light. My balcony is east facing with an overhang. Gets about 4-6 hours of direct sunlight. Don't think that my fire escape got much more.

The most important thing is that it's growing and I can eat it. If all of the leaves were yellowing, I'd be really concerned. We'll see what happens after I pick them.

Thanks for the input.
Bwilson7064 June 25, 2010 at 4:10 pm -

I have the same yellow leaves problem with my herbs. My fire escape faces south and gets very hot in the mid day sun. I did forget to water for a few days and they are in rather small pots. I will try more watering and larger pots. Will let you know if that works.
this_urban_homestead June 28, 2010 at 3:40 pm -

Ugh! You are playing the guessing game like I am. I have blossom end rot on some very newly formed tomatoes. The causes? Lack of calcium, too much nitrogen, or maybe uneven watering! BAH!
Mike Lieberman June 28, 2010 at 4:08 pm -

Most definitely a guessing game. There is no one right answer. It's good to know what it could be though.
Kristen July 3, 2010 at 4:22 am -

I had the same problem with some leaves on my tomato plant… picked them off and (fingers crossed) they haven't come back!
Mike Lieberman July 3, 2010 at 5:23 pm -

You'll figga it out.
mememe July 21, 2010 at 11:36 am -

Yellow leaves can be caused due to specifc things but kale requires a minimum of 4hrs of sunlight so if ur giving i that, its should be fine:P

i think the main reason causing this is because it is dying out, it is overgrown and it needs to be harvested.
Mike Lieberman July 21, 2010 at 2:24 pm -

Thanks for the tip. They've since been harvested…and eaten.
Mike Lieberman April 11, 2011 at 1:16 am -

Thanks. Appreciate the info.
Nina Rickett July 27, 2013 at 2:48 pm -

All of my kale is stunted in growing and it all turned yellow. Now all of my celery has turned yellow as well… Grrrr
M D November 24, 2013 at 5:00 am -

If your acid loving plants, like azaleas or gardenias are looking a little
yellow, mix 1 tbsp of vinegar to 2 cups of water and pour at the base
of the plant. Repeating this process every two weeks should turn that
yellow to green. Maybe it will work for Kale?
Guest April 3, 2015 at 4:57 pm -

My kale plant just developed one yellow leaf located on the outer edge. The plant started growing 12 months ago and survived a harsh winter. Lately the weather has been below freezing temperatures so I haven’t been watering it enough. The plant is in full sunlight. All other leaves look very healthy and growing.