food for flowering plants

So today i picked up a container of schultz bloom plus plant food. It says to use 1/2 tsp per gal of water with outdoors blooming potted plants. If i do this do i only need to thoroughly water both of my plants once ? I am un sure because this is my first time using bloom foods on plants (mine started pre flower) and when should i water them with this? Any help at all, thanks.

Pic of the plant food i got-

Use 1/2 of what it says and wait at least 10-14 days before giving it another dosage.

oo alright thanks. and when should i first water it ? 1-2 weeks after it begins flowering ?

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