ΔE 15.7, loose: different enough that you should pick on purpose. Straken Green is a little darker, cooler than Thicket Grove.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 16). Straken Green is a little darker, cooler than Thicket Grove.
The same difference applies the other way round: Thicket Grove is a little lighter, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Thicket Grove on the colour wheel See Straken Green on the colour wheel
All matches: Thicket Grove equivalents · Straken Green equivalents