Is this planted heavily enough?

Personally (my opinion) I would call your tank "moderately planted" at the moment. To get it to being heavily planted (IMO) it would need plants covering 75%+ of the total bottom surface. Your rocks and driftwood (I know you are going to add some more on the driftwood) have a bold presence in your tank right now, and the plants need to take that role in the beginning.

I finally listened to all the advice this time on setting up my 55 gallon, and made sure I had enough plants. I actually filled (and I mean FILLED) a 55 and a 20 gallon with all the plants I bought. I traded in the extra plants a day after I filled the tanks. Two weeks and everything was well established and the plants were nutrient hungry. I had to add 1/4 Nitrate and a few drops of Phosphate every day for the next week or it would become depleted . Now it's gotten to be about every other day. I'm about 1 month into this tank so far, and only minor traces of algae are seen. I have some serious light over this tank, though, so it may go a bit slower in your tank. I used Water Sprite over about 1/4 of my surface area (lower light side) and these have sent out roots like crazy.....looking for any nutrients to consume.

Do yourself a favor and at least buy some floaters for a couple months. You can always trade them or toss them (don't throw into a lake or stream.) I would also (just me) add some more ground cover to start filling in the bare substrate areas in the front. I do like your basic aquascaping, and I think the background will look good when the plants have filled in a bit. It may help add some more depth to your tank (looks like plants go farther back).

The background works really well if you plant the same plants that are in the picture in front of the background. I placed some Alternanthera Reineckii in my tank (not paying attention to my background) and the next day thought, WOW, those plants have really filled in! It turns out that it was just the background picture had the same plant right behind where I planted them......LOL! It looks really good, and adds several inches of apparent depth to an otherwise narrow (front to back) tank. 55 gallon tanks are hard to add depth to, so you gotta use any tricks you can!
 
Your tank looks nice, but I can still see gravel. :)
Get some for-ground plants, dwarf sag, dwarf sword, ect.

Here are some examples of a heavily planted tank. This guy has it going on...very nice tank.

I thought my tank was heavily planted!!. Must get more plants--must get more plants.
 
My 100 gallon is "heavily" planted right now I think. Here's a pic:

My 100 gallon tank

You have a decentply planted tank, Given decent conditions it should fill out well.

As always i suggest finding a way to inject some c02 into your mix. I can't emphasize what a difference c02 has made in my tanks.
 
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