Advice needed on planting in a newly designed garden...
We have recently terraced and designed our garden and it's time to start planting. I have two big flowerbeds, a couple of smaller squares (ca 70cm x 70cm), a narrow but deep trough at height... and various pots. The soil is heavy clay/alkaline and I've mixed in sand and top soil and dug the beds through (phew), but it's still quite heavy and lumpy... I've tried to choose plants that love that sort of thing... I've included two pics, one with annotations.
Some other considerations:
1. It's a south-facing garden but uphill on a north-facing slope, so while summers can be scorching because it's very sheltered, winters are dark and sun-less (and often wet..). You'll see the extreme terracing in the pics.
2. My main concern is picking a tree - i was thinking the evergreen magnolia but eucalyptus are also meant to be great for wet soils since they drink a lot, and they're very nice, too, and evergreen. And then the question is, where does it go? I was thinking the bottom flowerbed since it's the wettest and also has the most space (the squares on the left are only ca 70cm x 70cm) but I would love to hear views.
3. I'd like to have climbers on the sides since the walls on each side are tall and bare.
Thank you so much in advance.