I am always confused when told to deadhead various flowers, never certain exactly what part/s are supposed to be taken off etc.

My current question is regarding both upright and trailing geraniums and verbena. When the parts ( you see I'm so technical ) of the verbena that were flowering sort of 'dry up' should I take them off? I haven't been and some of them are starting to look a bit yellowish.

With the geraniums, do you just pull off the flowers or do you 'snip' directly behind where all the flowers were?

Sorry if this seems a tad simplistic, but I'm a newbie to gardening. Possibly a tad simplistic, too. lol