Combine strawberries, sugar, and water in a saucepan. Simmer over medium heat for 8 to 10 minutes until strawberries break down completely.
Remove from heat. Add basil leaves and press under the surface. Add lemon juice. Steep 15 to 20 minutes.
Strain through a fine mesh strainer pressing firmly to extract all liquid. Discard solids. Cool completely.
Juice lemons into a large pitcher. Add sugar and stir until completely dissolved. Add cold water and salt. Stir again.
Add cooled strawberry basil syrup to the pitcher starting with three-quarters. Stir. Taste and add more syrup as desired.
Adjust balance with more lemon juice, syrup, or a pinch of salt.
Fill glasses with ice. Pour lemonade over ice.
Garnish with strawberry slice, basil sprig, and lemon wheel.
Stir the pitcher before each subsequent pour. Serve immediately.