Sweet Rocket or Dames Rocket is reminiscent of phlox with a head that consists of a billowy cluster sweet white blooms.  Plant these where you want them to reseed.  Plants grow 3-4' tall.
 
An excellent cut flower, cut when blooms are 2/3 open.  It's fantastic in the landscape and lovely in the vase.  Plant 10-12" apart.
 
Seedlings come in 2.5" pots.  
 
There is no refund or warranty on plants after purchase.