Very few plants grow in full (never see the light of day) shade but the following list will grow in part to heavy shade depending on where you live.
- Abutilon
- Alchemilla mollis
- Astilbe
- Aucuba japonica
- Ajuga reptans
- Campanula portenschlagiana
- Coleus
- Heuchera
- Hydrangeas
- Hypericum
- Japanese Maple
- Japanese Painted Fern
- Lamium
- Lysimachia
- Mimulus
- Rehmannia elata
- Sollya heterophylla
I would recommend that you not plant directly under a lemon tree unless the tree is quite large. A young or middle-aged citrus can suffer from to frequent watering. If you are planting around the perimeter or the edge of a pot if that is how the lemon is planted, I might suggest:
- Thyme
- Rudbeckia
- short sunflowers
- coreopsis
- Scented geraniums
- Edible salvia
- Lavender