Smart! Growing things that grow well in your new home! Many people get all fancy about growing native wildflowers, and pay through the nose for native plants and seeds.
You went direct to the source! Bravo!
(Maybe ID each new addition to be sure you aren't planting something non-native and invasive! The plant ID forum is a great resource for that. If the photo is sharp and includes the identifying characteristics (whatever those are), they can nail down an ID in minutes to hours.)
If you are new to growing in clay, you have all my sympathy. Drainage and compost will eventually loosen your clay and make it drain better.
Until then, beware digging a hole down below grade, even if you fill it with wonderful, improved soil. If a hole-below-grade in low-perk clay doesn't have some kind of drainage trench to let the hole drain down and away, it will become a mud wallow or "bathtub", which drowns roots.
If you just plant INTO CLAY, at the same level as the surrounding clay, excess water runs off the surface instead of staying and drowning roots. That's why they how advise "amend the whole bed" instead of just "amend the planting hole". However, in REALLY bad clay, just amending the whole bed isn't enough. The deepest part of the amende4d bed needfs a path for water to get away, or it will drain down into the bed and stay there until it evaporates (after drowning your roots and killing your plants.)
Until then, consider raised beds. Even an 8" wall above grade assures that your plants will have a 7" deep root zone even if your yard floods 1" deep in that spot. Maybe even practice growing plants in containers for long periods. That's trickier than raised beds, but many gardeners have big "pot ghettos" and raise lots of healthy plants in containers.
Water drains down into holes, but then it stays there unless you give it an exit path.
