The Calabrese pepper has its origins in Italy, where it is prized for its hot taste and the attractive appearance of the small round, red peppers. It's often fried or pickled. The plants and seeds are not commonly found, so if you want to grow this Italian delicacy, you'll need to search for a specialty seed company. Like other hot peppers, the Calabrese thrives in soil that has plenty of compost and other organic materials and where it gets full sun.
Start seeds in pots or flats indoors about six weeks before your final spring frost. Fill your pots or flat with standard potting soil and then water well, until water comes out the drainage holes. Plant seeds the correct depth and distance apart, according to packet instructions. Cover your pots or flat with clear plastic to increase the temperature and keep the soil moist. Then set it in a sunny spot where the temperature remains above 60 degrees F at all times. Remove the plastic as soon as you see sprouts above the soil's surface.
Prepare the planting area by spreading a 3- to 4-inch layer of organic compost and other materials, such as grass clippings, on top of the soil where you plan to grow your peppers and then dig them under to a depth of 8 to 12 inches.
Set your Calabrese pepper plants into their permanent outdoor location after the final spring frost. Dig holes with a trowel that are large enough for the plants' roots and then gently set the peppers into the soil, covering them with additional soil with your hands or your trowel. Add a 1- to 2-inch layer of compost or other mulch around the plants to keep the soil moist and warm. Water thoroughly by running a sprinkler over the planting area for about 20 minutes and then water them at least once a week when the soil begins to dry out.
Fertilize your Calabrese peppers about one month after planting with a balanced plant food, such as one having an N-P-K ratio of 12-12-12. After that, give your plants one more feeding, but avoid fertilizing after the end of July because an early frost might damage new growth.
Spray your Calabrese plants with insecticidal soap as soon as you notice any sign of aphids or other insects. Spray in late afternoon when the area is in shade, and repeat your application every other day until all signs of the insects are gone.