It's not that unusual for certain seed to sprout very easily when left alone in the garden from year to year, while being difficult to sprout in a pot. The opposite can be true, too. Realize that the "in the garden" seed bank is a hundred times (or more) of what you have in your "in the pot" seed bank. Also take into account that the "in the garden" seed bank includes seed from previous years. Suddenly such a "failure" in the pot isn't so devastating.
