Is it just me or are your runes not showing up? o_O

Anyways, about your guide itself: You have a lot of things that I would definitely do/take on Zyra support. Several good things really popped out to me. I really like how you included Sweeping Lens once you get Sightstone, good use of coding/columns, and an example final build with both trinkets and enchantments :)

However, this being said, there are also quite a few things that I believe you should keep in mind. For one, your guide is not complete. Generally, you don't want to publish guides until you are 90% done with explanations and whatnot. I really recommend you add in chapters to explain Runes, Masteries, and Items. I can't see your runes (for some strange reason o_O), but your mastery tree looks fine from what I can tell.

Your items, on the other hand, should probably make up a good portion of your guide. While most of the choices are pretty good, there are some that I don't believe would be that great for a support. Namely, Rabadon's Deathcap. This item isn't very gold efficient if you don't have massive amounts of AP. As a support, you shouldn't be building a lot of damage, but instead be building mostly utility. In addition, the individual parts for Deathcap are super expensive and will be extremely difficult to save up for.

I personally really like the Rylai's Crystal Scepter/ Liandry's Torment duo on Zyra. Her plants will apply the slow/burn, and since the two items' passives work well together it'll do a lot of bonus damage. I'd recommend taking both of those items if you really want to go offensive :) (It also gives you tons of health, which is really nice since Zyra is squishy as heck)

For summoner spells there's no point in mentioning the non-viable ones. Speaking of which:

Clairvoyance and Ghost are really not viable choices. Flash is the only escape spell you need, and it's far more effective for getting out of trouble due to the incredibly fast cast time. Getting away from dangerous spells is far better than outrunning enemy champions, because they can usually still CC you and catch-up using gap-closers.

Clairvoyance is absolutely not something you can take. It does almost nothing of use. Other spells ( Heal, Ignite and Exhaust) can keep your carry alive in lane and/or setup kills. This spell contributes nothing to lane and very little utility elsewhere. Anyways you can already use Rampant Growth to reveal an area (the initial cast is about the same size as the reveal for the plant), rendering this spell even more useless.

Keep on working on the guide, there's definitely still a lot missing (item explanation, laning phase, team-fighting, etc.).