If you utilize a Plant deck, use multiple "Queen of Thorns" in order to force your opponent to pay Life Points to summon non-Plant monsters from their hand. This will be very effective against "Six Samurai" and "Tech Genus".
"Queen of Thorns" can potentially combo well with "Black Rose Dragon". If you manage to have both of these cards on your side of the field, your opponent will be forced to Set their non-Plant-Type monsters to avoid the effect of "Queen of Thorns". You can then easily use the effect of "Black Rose Dragon" to remove from play a Plant-Type monster from your Graveyard and activate its ATK reduction ability on an opponent's face-down monster since its effect also targets monsters that are set face-down, not just in face-up defense position.
A Zombie Deck can make use of this card, using Graveyard power to summon monsters without taking damage.
This works well against non-Plant Pendulum decks as they focus on summoning multiple monsters from hand but it can be avoided by Pendulum Summoning from the Extra Deck