How do I plant seeds?

[Black Jesus]

Also why do invasions bypass defenses and spawn underground randomly? Kinda negates the point of having defenses.

[Graknorke]

Seeds are for the planter boxes (I forgot the name of them) in the bottom right of the raw materials research tree. After the building that lets you speed up growth rate.

[Prometheus0000]

The fact you can't replant stuff is like oxygen not included (and a whole lot of the game it looks like), but that game gives you a clearer route to farming. It's completely not obvious you won't be able to replant stuff after removing it, so you can easily screw yourself over (or so it looks like). It should be mentioned in the tutorial.

[FreedomFighter]

Originally posted by Black Jesus:

Also why do invasions bypass defenses and spawn underground randomly? Kinda negates the point of having defenses.

If the infected grave that trigger to attack your city has no direct route to it, it will dig into your city instead. So for now, go out and explore. If you found a grave then clear the path for it to your city.