This will give you and your kids a hands-on project all summer that will give them ownership.  Plant an organic garden.  I must admit that I used to not have a “green thumb”.  Over the years, I have “cultivated” one.  In early spring I purchase organic seed packets or save seeds from fruits and vegetables that I have grown in earlier seasons.  Begin by sprouting some in small containers with drainage holes.  Our soil got depleted from earlier tomato crops, so now I am attempting to revitalize the soil in one area of our garden.  I have planted corn, pinto beans, and pumpkins together with sunflowers growing on the side for fun.  My husband asked the gardener at his work for the bag of leaves he was about to get rid of.  Along with good compost soil, I have laid a layer of leaves around all the newly planted sprouts and have, additionally, added some topsoil.  Already, the soil is transforming.  I unearthed a red worm the other day, so there is some sign of life!  You don’t need a lot of growing space.  Since lettuce prefers cooler weather, I have some growing in a pot in a shaded area of my patio.  You may want to have planter themes.  For example, if you enjoy Italian food you might want to plant tomatoes, basil, oregano, rosemary, zucchini, squash, bell peppers, and green onions.  At harvest time, make a pizza or spaghetti together.  You can do math while growing plants.  After planting two sunflowers sprouts (or corn, etc.), take a daily measurement using inches and centimeters.  Scientifically try to reason why one plant is growing faster than others.  Make a mosaic art project using old or unwanted seeds.  Studies have shown that eating healthy food, being physically active, not watching too much television, and getting the right amount of sleep contributes to higher academic success.  Your children/students will continue learning throughout their summer while getting outdoor exercise, nutrition, and enjoyment.