In a small bowl, whisk together oil, vinegar, salt, pepper, and tarragon.
Thinly slice cucumber. Split 30 of the fatter peapods and remove the peas; set aside. Gently rinse chervil, mâche, and mesclun and gently spin twice in a salad spinner to thoroughly dry the leaves.
Put greens in a large bowl and toss gently but thoroughly with 3 tbsp. dressing (leaves should be barely coated), adding more dressing if necessary.
Divide greens among plates. To each salad, add a few slices of cucumber, some sugar snap peas (both whole pods and just the peas), and some radishes. Drizzle with any remaining dressing, if you like, and top with whole flowers and flower petals.
*Use only unsprayed, organic petals and blooms. If you're growing your own flowers from seedlings, be sure to buy organic plants—and don't spray them as they grow. To buy edible flowers, try gourmet grocery stores and farmers' markets; avoid flowers from florists and nurseries.
Note: Nutritional analysis is per serving.