Ok, so this is something that I can work with.
First, I suggest siding the Hedge Guard. It isn't worth using against many decks so just side it in when you think it'll actually be useful. Soldier of Mist Valley looks random here, especially since you don't have both Brain Control and Mind Control. Rose Tentacles is only useful in the Black Garden build. It's actually a pretty awful card outside of that build. You should definitely be adding in some copies of Gigantic Cephalotus. He's a nice, easily summoned beatstick. I'd also consider maxing out on Botanical Lion. Remember that the Lion's stats are basically 1900/2000 and they increase if you have another Plant monster on the field. He's 1 of the best beatsticks available in a Plant deck and has some of the best stats of any 4 star monster. You can also try adding Violet Witch, who is a good searcher, although Sangan may be enough in some cases. Since your monster count seems somewhat low, you may want to consider adding in an LS engine of 2 Ryko, 2 Lyla, and 2 Light Brigade. That will give you more effects that destroy your opponent's cards while also loading up the grave for Lord Poison and Pot of Avarice. You should also consider maxing out Tytannial and definitely do so if you add the LS engine.
For your s/t cards, Fissure is a bad card choice. Smashing Ground will always be better and neither will be needed if you decide to run the LS engine because Ryko will take care of you in that respect. You should never need 2x Lightning Vortex. 1 should always be enough. Mark of the Rose is a fun and interesting card, but it messes with the targets for Pot of Avarice and Lord Poison and it can't be used early on in the duel. Pollinosis is tough to use properly outside of a Black Garden deck, because you don't have those extra tokens from Black Garden that you can tribute. Wall of Thorns, like Mirror Force, is sort of a card that you have to be careful when maining. It isn't chainable, and unlike Mirror Force it's also slightly more situational. I suggest keeping a couple copies of it in the side to make sure your opponent isn't using a deck that can easily clear your field each turn before siding it in. Pot of Avarice is an important card for the deck and you should have at least 2 mained. Definitely max it out if you add the LS engine. I'd toss out the Threatening Roar. It was an awesome card in the March format, but now there are slightly less OTK-style decks . . . it's more about control, so you probably won't be needing Threatening Roar like you did last format.
An alternate way to play this deck if you don't add the LS engine is to add in Barbaros, Skill Drain, and Trade-In, then use less copies of cards that could get hurt by Skill Drain like Botanical Lion and Twilight Rose Knight. Trade-In works for both Barbaros and Tytannial so you should have plenty of targets for it.
If you decide to keep the Marks of the Rose, then I'd suggest also adding in Mind Control, then having even more tuners such as Gale and maybe E Tele + Krebons/Psychic Commander.
If you decide to run the LS engine, other cards to consider are Necro Gardna and Plaguespreader Zombie.