Very unlikely. While it is high in phos it is still just a rather basic fertilizer (although spikes like that are totally dependent on your watering regimen to work). The cause if far more likely to be something in either the variety - have asked for the name in your other post - or in the weather or the growing conditions you have provided it. Is it in a container or ground? What size container? What mix used? How much and how often do your water? Age of plant?

Need much more information from you to be of any help.

Dave

"likely to be something in either the variety "

Agreed!

I believe, the NPK ratio is off. Normally plants need 3 times as much N than P. Here what you have seems to be quite the opposite. I am not suggesting that it can cause bitterness. JMO

Sey

One can wonder about what is in this fertilizer besides NPK. The NPK numbers are just that. The amounts of N, P and K. But there is more to what you sprinkle on than N, P, and K. If this fertilizer wasn't over-applied, it's hard to believe that 2-4-7 would do anything bad, or even that noticeable.

Thank you all who responded to my question!!!

I dont know the variety, but it seems that might be a factor since a different variety growing in the same conditions does taste better.

the plants are in the soil and it is fairly heavy clay soil with some compost mixed in. The problem is probably that it has been raining a lot lately and the spikes must have dissolved a lot faster than they should have.