It depends on whether you're steaming them with or without the locally harvested golf balls. If they're recently retrieved from the yard, they're tender and steam quickly and compliment the artichokes nicely. If it is a ball that has lodged in a grassy hillock somewhere near the fence and been sun-baked for weeks or months, steaming takes considerably longer. And forget marinades, they just don't help. You need to serve them with a strong flavored sauce.