Answer: Sunflower seed hulls are somewhat allelopathic, meaning they may inhibit the growth of some other plants. In my experience a small quantity in the compost pile does no harm, but I would hesitate to add a disproportionate amount of them at a time. Do be sure too that the compost is well processed and "finished" before applying it to the garden. This should help ensure that the chemicals in the hulls are well dispersed.
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