In a large deep skillet, fry the bacon over medium-low heat until crispy. Remove from the pan and set aside.
Discard most of the bacon grease, leaving only about 2-3 teaspoons.
Reduce the heat to low and add 1 Tablespoon of the butter to the bacon grease. Add the shallot and garlic. Sauté for 4-5 minutes. While the shallot and garlic cook, bring the broth to a simmer in a large saucepan.
Increase the heat to medium. Add another Tablespoon of the butter, the zucchini, salt, thyme, and pepper to the shallot mixture. Sauté for about 5 minutes.
Add the rice and sauté for 2-3 minutes.
Deglaze the pan with the white wine. Reduce until the wine is gone.
Add about 2/3 cup of the warm broth. Stir continuously until the rice has absorbed all of the liquid.
Repeat this process until all of the broth is gone, only adding about 2/3 cup of broth at a time. This will take about 20-25 minutes in total. The rice should be soft, but still have a bite to it. If the rice is not done, reduce the heat to medium-low and continue stirring.
Remove from the heat. Stir in the remaining butter and parmesan cheese.
Stir in the lemon zest and juice. Taste and add salt if needed.
Crumble the cooked bacon and serve on top of the risotto.