Can't harvest seagrass from tall seagrass

using shears, I am able to harvest 1 seagrass from natural and artificial seagrass blocks. As the Wiki states, this is normal behavior. However, I should also be able to get 2 seagrass from tall seagrass. Using the shears I break the tall seagrass and I get nothing. This makes seagrass a very finite resource as I have to venture far from my base in the world made in 1.12.2 to get to 1.13 chunks. This makes turtle farming very difficult as I can't get much seagrass.