There are very few trees which will tolerate deep shade since their instincts are to grow up to the light.
However, since most gardens have shady spots the trees which will thrive there are especially valuable.
|Acer||palmatum and cultivars|
|Ilex||aquifolium and cultivars|
|Prunus||laurocerasus and cultivars|
|Prunus||lusitanica and cultivars|