Would it be better to dig out the clay in my planting bed and replace it with better soil than to ammend the clay?
No. Contrary to the belief of many people digging out the clay and replacing it will not benefit your plants. First of all, you will create a “bowl” or “vase” that will actually hold the water and you may drown your plants. Second of all, your plants may grow well at first in the “good” soil, but when the roots hit the clay, they will not be strong enough to push through it. Your plants may actually become root bound in the hole.
