In my early days of collecting, filled with rampant paranoia about earthquakes in Southern California, I avoided all breakable items. Not so anymore! This was the very first vintage breakable item I ever bought.
This is the Alice Heart planter, by Leeds China Company of Chicago. There is some confusion about what role Leeds actually had. Most people think that Leeds was actually not the manufacturer but rather a distributor; production being done by many different companies including American Bisque, American Pottery and Regal China. To my knowledge there is no way to distinguish any differences between manufacturers.
There is no makers mark on the planter, but there is a bold copyright notice on the bottom.
The Alice heart planter is from later in the Leeds line, which started back in the 1940s; they did lots of pieces. Most of the salt and pepper shakers, cookie jars and planters you see with Dumbo, Mickey, Donald, and Bambi figures are by Leeds. Alice and Peter Pan were the last two films for which Leeds produced pieces, and as such they are much harder to find (the Peter Pan Treasure Chest planter is exceedingly hard to find). The heart planter is by far the most common of the Alice pieces, I'm pretty sure the reason is that it makes a damn fine Valentine's Day present.
The Alice Heart planter does have a variation (yay!), that being the same planter with gold highlights.
The gold highlight version is quite scarce, you will see perhaps hundreds of unhighlighted planters before seeing a highlighted one.