How will the scenery be in early March?

Sakuras bloom in the south first and then moves it way up north. Depending on the weather in Japan now, it might still be a bit too early for sakuras in early March. You might have better luck in Fukuoka or Osaka, or like others have suggested, peach blossom.

You might want to check this link in March:
http://www.jma.go.jp/jma/en/Tourists/indexe_tourists.html

I know they update cherry blossom blooming dates in early March.

If you want to see cherry blossoms in particular, I'd recommend going in late March, early April.

Early March can go either way. Snow is still possible, or else it might be quite warm and Spring-like. It's a little early for sakura, but there will be plenty of other things blooming and budding-like the other answer says peach blossoms will be out.

Tokyo/kyoto is always worth visiting regardless of the weather... there is always the food !!!!!
but otherwise spring or fall are the best times temperature wise.
Summer can get super hot and rainy season super humid "mushi-atsui"
Winter gets cold, and can have snow, but visiting old castles and temples in the snow is also awesome.
Won't be any sakuras yet.

if you haven;t been before... goto Tsukiji market, tokyo tower, akihabara, harajuku, kyoto castle, and every different kind of restaurant you can get to :)

have fun

there will probably be no sakura trees but they probably will have peach blossoms i think
I think that if you dont like HOT weather, you should go in march
it will probably be like, just the perfect temperature