FOCUSING IN CLOSEUPS WITH KIT LENS.

welcome to forum......My opinion differs here regarding your photograph.... IT IS NOT THAT U BROUGHT 550D in front of the flower and shot only one photo....What I feel here, if anybody wants good flowers photographs, focus on the stamen...the judgement of sharpness begins from stamen and the stamen in ur flower is diffused. IT is the case of simply not focusing correctly.
U r new to DSLR...however there is LCD screen to check sharpness and exposure....even with kit lens at 5 inches u will get good focusing on this type of flower at 5.6....however since it is a closeup photography, f8 and f11 r necessary.
--I recommend Shobin's point of underexposing by half stop....As I set my all cameras at  half stop minus compensation....In low light I may change to 0 compensation....so it is a matter of choice and lighting conditions....You keep on aperture priority, u shd have to check the aperture each time u remove the lens cap. Otherwise for learning photography and correct exposure setting with Shutter speed and aperture, which play main role, try in MANUAL settings....Once u master and keep reading the light, aperture priority will certainly of great help, finding out the DOF importantly and for high speed shooting Shutter priority I prefer....all the best, Anand.

It is simple Anand...ur autofocus system told u that the flower is in focus...yes, the petals look sharp and there are many points of autofocus on the screen in viewfinder...I generally keep set the point in centre...so I feel less worried...As M_BHAKT says u might have went too close to flower......In closeup focusing with kit lens we move up and down and here ur autofocus system, u thought is working.....I tried with my kit lens, that when I went below the fixed range of focusing, say 5'', there is autofocus signal but no BEEP. Just went above to 5 inch, the beep was heard and that confirmed that the subject is in focus........just remember and pl go through the manual as many times u can...There are assortment of features...Definite they help a lot so we are more confident while shooting.....macros,closeups to landscapes, portraits..and and......just guess??....(with due apology to Anand)....JJmehta forum.