Growth 0.01? Is that a glitch?

There are many systems at work and the easiest thing to miss is the adjacency and moral bonuses. It's not very clear by the improvement type in the tool tip is tells you which bonuses will level the improvement. There are also growth improvements with other adjacency types (Colonization Center levels with All Construction). I'm my current game I'm playing the Korath and turn 31 I have 0.07 (1 pop every ~15 turns) pop even with a -15% growth penalty.

One of the first buildings you build is the colonization center. It's 0.01 natural growth plus 0.01 growth per "all construction" adjacency level. In my example, I have a level 3 but you can easily stack it to 9 or 10 and get 0.10 growth per turn so you'll need those cities.  You will also get up to 50% growth bonus from high moral. Then in the tech tree there are two primary routes although you can take both. Colonization has a hospital line (percentile growth) and Governance has the Immigration line has flat growth options but moral penalty.

If you play around with it you'll find you can stack it quite well and then "shuttle" people off with a Colony ship to colonies that have worse growth. 

Thank you for the well written response.  I will play around some more.  In the past population grew on all colonies at 0.1.  You are describing getting 1 planet up to that level by turn 31.  I've been playing small maps but I have yet to have the need to build cities.  The "city" building is a very early tech too.  Seems strange to give us a building that has no use so early on.  I read one of Brad's posts about the update and he mentioned they lowered asteroids from 1 to 0.5 because they wanted to make population stronger.  Major population just isn't possible in the short game.  

It's weird that an ideology can give you a fully loaded colony ship and you can go from 5 pop to 10 pop just like that.  Growing that population would have taken so much longer!

The switch to 0.01 was made a few updates ago, along with the tech paths and buildings to increase growth (hospitals were already there, but not the flat growth/reduced happiness path).  It was intended to make population growth a decision (in terms of research and buildings) rather than let all civs grow fast together.