Courser isn't all that expensive now, since it is in the clash pack (around 9-10 dollars from tcg average, I just checked myself). If you wanted to get them, I'd get multiple copies of the clash pack, as some of the alternate arts could be valuable in the future.

For sideboard, I'd recommend Soul of New Phyrexia , it's especially useful in the control matchup, as you get at least one activation, unless they run Dissipate . Is your local metagame running a lot of constellation decks? If so, you can keep some of the Back to Nature , but four is excessive. I'd recommend running 1-2 Reclamation Sage , as they provide devotion, can target anything you need it to, and they can be hit off of Genesis Hydra . Four of the archetype is really excessive, I would only run one at the most. If you have problems with planeswalkers, I"d recommend Pithing Needle . If you have trouble with fliers, I think Plummet is okay, but Arbor Colossus can handle fliers just fine. Maybe Restock so you can get some things back in longer games?

Splashing for red isn't extremely difficult land wise, as Temple of Abandon is relatively cheap now, as is the Xenagod.

Nice deck

agree with scopesightzx about Reclamation Sage it is more versatile and is rarely a dead card.

I would run Voyaging Satyr in place of Golden Hind , it is a better defender (early game) and enable shenanigans with Nykthos, Shrine to Nyx

Thanks never woulld have thought about Voyaging Satyr . Will think about throwing in Reclamation Sage

Have you considered Nissa, Worldwaker ? You run enough forests to make it quite strong

yeah i have many times, but Nissa, Worldwaker is too expensive. If she wasn't so expensive i would have ran her a long time ago

I would add Ranger's Guile to the sideboard to help defend your critical guys. Also consider the hasty Mistcutter Hydra . While mono blue seems gone, a lot of the 3 color decks have blue in them, and the synergy with Solidarity of Heroes is ludicrous.

Mistcutter & solidarity are both already in there

I was thinking about your comment where you said that you'd consider looking at the Genesis Hydra + Invasive Species combo and thought I would point something out.You can get a very similar effect from playing a Roaring Primadox over an Invasive Species and it would cost you less mana to pull off as long as you did it two or more times. I know that mana isn't really an issue on the ramp deck, but you are saving almost a whole pump of mana you could be putting on to Heroes' Bane . You probably thought of this already but if you didn't I hope it gives you something fun to try out at least!

My buddy runs a very similar deck but he runs Polukranos, World Eater , Heroes' Bane , and Scourge of Skola Vale as his hydras, he's normally finishes top 8 at our lgs