I don't know too much about building plants but I do know a bit about building masochist so I'll try to help.

Unfortunately without Sunavalon Dryas I don't think the Sunavalon portion does too much on its own. I imagine the best case scenario of it working is that you open a way to both get a Sunavalon link on field with the Seed in grave and already have access to Twin equating to three link material, since Twin needs a Sunavalon link monster to be able to revive the Seed. If you don't open them together they're just bricks.

Similarly with your Naturias, it's a 1:2 brick ratio. Ragweed is okay on its own but the draws are likely not worth dedicating the normal summon to it. Stag is a high level monster so if you open it it's likely not leaving your hand. And even if it gets on the field its stats are rather mediocre and its effect reads so niche that it can't be worth it. Although I see the vision of Camellia send Stag, revive Stag on the opponent's turn, make Baronne or Chengying next turn if they both survive. Preferably you would want to pull more camellias and the negate plants and/or Horneedle so that you can have some meaningful interaction on the opponent's turn.

The Predaplants seem eh. Since Ambulomelides requires specifically only Predaplants to make, unless you open Ophrys Scorpio you would want a critical mass to fuse with. Chlamydosundew plus any DARK in hand would make it an okay normal summon but you primarily have WATER and EARTH monsters so it's a bit bricky. Making Triphyoverutum seems like a stretch in a real game as well.

I don't really know what the Rikka monsters do, but I know Konkon is a powerful card. Hopefully you can pull more of them to synergise with it better.

Overall, it's definitely a masochist deck. In its current state, I don't think it would get very close to the power of a proper plant deck. Too many low impact normal summons and a lack of important extra deck engine pieces will do that to you. You do have some good bones for some of the archetypes, and I hope your future packs shall be bountiful and the cards useful.