I can tell that the flowers are producing seed now and will soon 'dehis' (technical term for falling off on purpose) instead of the plant just wilting from lack of nutrients because the stems are turning color below the flower heads.
Cutting the stems at an angle and as close as you can to where the first leaf below the flower attaches to the stem (the leaf axle) makes your plant look very nice and it maximizes the remaining leaf area. Your plant will need all the leaves it can get to produce enough carbohydrates to survive the Summer. It will need to grow new roots to take up nutrients and to repair or replace damaged (including sun burned - yes plants can sunburn! - tissues).
If all goes well here in Southern Nevada, this daisy mum will bloom again this Fall.
|Time to dead-head these mums.|
|Prune with anvil towards plant.|
|Prune at leaf axle.|
|Not wilting, ready to produce seed.|
|Plant will allocate resources to new leaves and roots now.|
|The pruned blooms make great mulch.|
|Properly pruned, these mums will look great until they are ready to produce new blooms.|