Plants should grow just fine in about any water conditions, without any additives like fertilizers.
Fertilizers can then be added after the plants have adapted to your water conditions/parameters to add extra nutrients to the plants.
One HUGE thing for a well planted aquarium is how much light your tank has, and what kind of substrate you are using.
Those two things will determine a lot if your tank can effectively sustain live plants.
If I were you, I would aim somewhere around 1.5 WPG (Watts per gallon) of light.
With 1.5 WPG, you can get a pretty wide range of plants.
As for substrates, I would look in to substrates made for plants, like this here.
http
/www.caribsea.com/pages/products/planted_aquar.html
Other than that, plants will actually use ammonia and nitrate as a source of extra nutrients.
I would have to say, IME & IMO, plants are not really effected all that much be temperature (within a limit), KH, GH or pH.
Now, as far as Co2 goes, if you have an aerator in your tank, you are going to have around 6-8 ppm of Co2 in your tank at all times, which is just fine if you have no more than 1.5 WPG.
Now, if your lights are over 2 WPG, than you are going to have to start thinking about getting a pressurized Co2 system and pump Co2 directly into your tank. If this is done properly, the Co2 level in your tank will be around 30 ppm.
Having over 2 WPG and pumping Co2 into a tank is many for fish keepers that are aiming for a very HEAVILY planted aqaurium, and I would not suggest to do that until you have built up enough experience about plants, and are then willing to take that extra step.
As for right now, 1 - 1.5 WPG, and adding a fertilizer like Seachmen, you are going to have a very nice planted tank.
-FHM
