It May Improve Her Health:
This hygiene hypothesis (the belief that dirt can protect children from allergies or illness) continues to be studied. While scientists debate the issue, the take-away for parents is this: playing in dirt isn't so bad and may be helpful. However, you should still follow rules of good health, including teaching your child to wash her hands after playing in the mud or being exposed to germs. And, as even Dr. Ruebush notes, you should keep vaccines up to date since they provide an important boost to immunity.
He'll Get to Use All His Senses:
Research shows that when multiple senses are stimulated the brain is more likely to remember what’s being learned. So try teaching counting or colors or new words by using natural materials that engage multiple senses (think aromatic flowers, rough sticks, or odd-shaped rocks).
She'll Build Motor Skills:
On the other hand, give your child large sheets of paper, a bit of washable paint, and any number of fun tools for painting and you're more likely to see her get more excited and motivated to use those small hand and finger muscles. These muscles are the ones she'll use for everything from self feeding to buttoning a jacket to writing with a pencil.
Encouraging these fine motor skills, then, encourages independence as well. Just as importantly, though, give your child some creative tools and you'll end up with walls full of beautiful artwork to enjoy.
You May Raise a Scientist:
Given the chance to climb, roll, crawl, and jump freely, your little explorer can change that area can into anything he wants. It's also where he can test out "what if": What if I dump some water in that dirt hole? What if I pull some branches off of that tree? Here, your child can start asking questions, making observations, changing the situation to see if it changes the outcome. Yes, he will get filthy, but he will also be thinking like a scientist, which will set him on a path to asking and answering many more questions in the years to come.
She May Get Better at Cleaning Up:
First, consider creating a zone (one indoors, one outdoors) where your child can make a mess and doesn’t have to clean up right away. Fill this area with toys and materials that encourage dramatic and constructive play.
Next, help your child prepare for the transition from messy play to clean up by giving her notice 15-minutes beforehand that it's almost time to clean up. Remind her in 10 minutes, and then about 2 minutes before it's time, remind her again as you start picking up pieces of the activity and talking about what you're doing next (it helps to make the next thing sound really exciting -- even if it's nap time).
Give your child special clean up tools like a dustpan and brush or even a clean up apron and start singing a song like Barney's famous "Everybody Clean Up" tune. In this way, clean up feels like a game as well and can help you encourage good habits -- to follow the good dirtying up.