Squeeze lime juice into a large bowl. Gradually whisk in oil in a slow trickle until fully incorporated and thickened. Whisk in honey, mint, vanilla, and poppyseeds.
Add peaches, mango, grapes, watermelon, and blueberries to the bowl. Mix thoroughly, cover, and refrigerate for 1 hour or up to 6 hours.
Fold in raspberries and strawberries just before serving. Serve it with Panera Bread Orange Scones.
Tip: To peel and pit the peach, cut a small X in the bottom, drop it in boiling water for 1 minute, and then transfer to ice water. When cool, scrape off the peel with a paring knife. Cut the peach lengthwise around the pit, twist to separate the halves, and pop out the pit. For the mango, cut it in half lengthwise around the pit, cutting as close to the pit as possible. Cut the mango lengthwise into 1-inch wide strips, and then cut the flesh from the peel, holding each strip peel-side down on the cutting board.