Just noticed, Zyra's plants don't activate lifesteal. Or maybe they do...?

Is it the same for all summoned minions or just a bug? If not a bug, why? Is it because it has a different type of health? I think it has 2hp and a hit is an enforced 1 damage. Is that it? The damage dealt and health returned are so small, there isn't even a message for it?

Edit: clarification - i was playing as Cait in aram and had and . Grevious wounds was on and healed accordingly from minions, but no health came from Zyra's summoned plants. Healing occurred normally from minions after Wounds expired, but still no health from the plants. I only noticed it when there were no minions around to leech from.