When this card is flipped face-up: You can choose a number from 1 to 5, then excavate that many cards from the top of your Deck, send any excavated Plant-Type monsters to the Graveyard, also place the other cards on the bottom of your Deck in any order. If this card is excavated from the Deck and sent to the Graveyard by a card effect: You can target 1 Spell/Trap Card on the field; destroy that target.
Rose Lover and Amarylease are plant type monsters that benefit from Sylvan Komushroomo's effect since they are activateable from the graveyard. Using their effect helps with special summoning higher level plant monsters easier.
Using monsters on the graveyard, you can use Powerful Rebirth to special summon from the graveyard. It's limited to level 4 or lower monsters only, but you can use Lord Poison to attack into your opponent's monster so you can special summon a higher level from your graveyard.
Magical Merchant is not a plant type monster but its effect helps excavate and send to the graveyard, which compliments the Sylvan monsters play style, and can help speed up the process. Sylvan Waterslide is a trap version of the effect so you can activate it when your opponent attacks. Depending on the Sylvan monsters you use in the deck, this can potentially turn the duel around.
Sylvan Marshalleaf, World Carrotweight Champion & Rose Lover
Sylvan Marshalleaf is another card you want to get from this card effect for destroying your opponent’s backrow.
World Carrotweight Champion is a good card to be sent to the graveyard with the effect of Sylvan card. If it is in the graveyard and you have Rose Lover in your hand, activate the effect of World Carrotweight Champion to special summon itself from the graveyard to your side of the field by discarding Rose Lover. Then you'll get another chance of special summoning a monster with the effect of Rose Lover.