Harvesting is a big one. Picking ripe fruits from trees, picking annual vegetables like the usual tomatoes and cucumbers. Going out at night and picking slugs off the brassicas or placing beer traps. Spreading wood chips around the base of trees. Watering with compost tea, gathering weeds for said tea. Chop and drop weeds. Gathering eggs, clean coop, feed chickens, water chickens. Spread soiled chicken bedding amongst perennials. Water annuals if needed. If you have other animals there’s allot to do there. Trim overgrowth if needed. A ten year old can do all of these things.