kale various vegetables Vegetables

Kale, Cauliflower, Broccoli, Collards – Keep This in Mind

This bit of information might be useful when you’re planning what to plant where.

If you raise or plan to raise cole crops, such as broccoli, kale, collards, and cauliflower. They — ” leave a chemical residue in the soil called thiocyanate. “  While —”this natural substance protects these plants from soil- dwelling insects and weeds……..it also inhibits germination of any seeds, including lettuce seeds planted nearby during the season. However, by the following season, the thiocyanate breaks down and is no problem.”

Lettuce seedlings will fare just fine.  It is only the germination of seed that is effected.

I happened upon this information when one of my readers had a problem with seed germination that may have been attributed to this. The problem came up again one evening when I spoke to another of TMG’s readers.


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  • aha!! I had some corn salad and a little kale that overwintered in one of my raised beds. I pulled the corn salad this spring and planted spinach…which wouldn’t grow until now (in this hear ) I wonder if the corn salad left the same residue.

  • I don’t know if corn salad leaves that residue or not. I’ve never read anything about it, but if I come across anything I’ll let you know.


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