Planters or containers filled with annuals need frequent fertilizing. Every time you water you are flushing out nutrients that need to be replaced. The recommendation is to fertilize weekly at no more than half strength.......weekly weakly :-))

Thank you gardengal

I fertilize all my container annuals every week. Fertilizer Friday!

Every time you water you are flushing out nutrients that need to be replaced.

==>> presuming the pot has drainage,.. and they are actually flooding the plants with enough water for it to actually flush out the bottom ...

its been very coldish in my MI ... and OP is in z4 .. though the last week might have been warm.. it might not have been warm enough.. including all night.. for the fast growth of a warm season plant like these ...

always remember.. its not how warm the day is.. its how cold the soil gets where the roots are.. gets at night .. and pots dont retain warmth.. like mother earth might ...

just be patient ... quell those instant gratification needs ..

many peeps just use 1/4 strength water sol fert to every watering ... just to maintain fert .. without worry about over dosing a pot ... sooo.. its a watering can thing ... i used to keep a gal milk jug of fert around.. and just put one quart into the watering can .. and then fill with water.. and come to think of it.. it was a 2 gal can.. so i was down to 1/8 strength ...

ken