Summer crops grow best at temperatures between 75° and 85°F during the daytime and 60° and 75°F at night, so maintain grow area temperature according to plants need. If its winter then the grow area temperature should be between 60° and 65°F during the daytime and around 50°F at night. You can place a heating pad made for plants and provide accurate air circulation to keep your plants energetic. You need to use compost that is specially designed for containers, as it will hold onto water better and have extra nutrients to get your plants off to a good start. Since rain cannot reach your plants, provide them enough water but avoid excess watering because too much water can result in disease.
Aphids, mites, and whiteflies can attack your windowsill vegetable garden so try to spray the entire plant with lukewarm water. In your windowsill garden, you can grow vegetables that take up little space, such as carrots, radishes, and lettuce, or crops that bear fruits over a period of time, such as tomatoes and peppers, for best use of space.