This will come on your way to 250,000 pts.
This will just take time...pts per flower are the same throughout all levels, but the higher the level the greater the "After Round Bonus". Suggest to play Expert for more points per time spent...but I would stick to Standard until you earn level 20 once.

The Green Thumb achievement in Flowerz (WP) worth 57 pointsReach level 20 in a single game of Standard or Expert mode.