I had this problem all the time in Nevada.

With few exceptions, all the kids I tried to employ were worse than useless. The few exceptions were kids who were raised in ranching families who had to sell the outfit and move to town for some reason. I had kids who I told to show up in boots, long pants and with gloves that fit them. They'd show up in shorts, flip-flops and with no gloves. Their parents then would yell at me when I would fire them - because they showed up without the proper work attire.

In hindsight, for liability reasons, I wouldn't hire a kid under 18 ever again for anything other than sweeping floors and maybe mopping them. Lawyers have explained to me what a risk I was taking in hiring 16 & 17 year olds and turning them loose with power tools like weed whackers and simple things like pitchforks.

 
You should also be aware that, while the federal minimum age for employing a minor is 14, state laws can further restrict your ability to employ a minor. eg, Some states have very specific laws against employing minors with any power tool that could cause significant injury.