Lemon Juice
Health
Lemons are a great source of Vitamin C and Citric Acid. Vitamin C has been shown to reduce the risk of heart disease and stroke and help the absorption of Iron thus being useful in treating anaemia. Citric Acid has been shown to help avoid kidney stones forming by raising the pH of Urine and making it more difficult for them to form.
Drinking lemon water is a great way to get a vitamin C boost. Vitamin C also is a good antioxidant and and daily glass of lemon water can help prevent illness. reference reference
In addition to these health benefits, the citric acid in lemon juice helps make it a great cleaning product! From cleaning pots and pans, removing stains from marble work tops, to killing bacteria on cutting boards or removing odors from your microwave. reference
Folklore and witchcraft
Overall, lemons are strongly associated with cleansing or repelling evil and attracting prosperity. The concept of prosperity is often expanded to include all good things, including fertility. Lemons are also frequently employed as catalysts in luck formulas. Lemon blossoms, in particular, are considered a powerful attractant for positive things.
One of the easiest ways to use lemons is in the lemon energy cleanse. Take a fresh lemon and either use it whole or cut it into slices. If you slice it, sprinkle the slices with salt, and place them in the most high-traffic areas of your home — places like living rooms and dining rooms. Give the lemon a few days, then give it a look over. If it’s neatly dried, then all’s well. If it’s soft, discolored, bad-smelling, or moldy, repeat the process with a fresh lemon.
Using lemon juice as a cleansing wash not only cleans well as described above but can be used to remove bad or stagnant energy. In general, lemons are a good thing to keep around where people (especially guests) congregate. You never know what kind of energy other people are bringing in, so keeping some fresh lemons where you usually socialize is a good way to counteract any kind of negative energy. reference
Lemons are also associated with the element of water and the goddess Artemis, who is often invoked for protection, purification, and healing. When combined with other herbs or oils, lemons can be used to create powerful spell ingredients that can help bring positive change to your life.
In hoodoo, a form of African American folk magick, lemons are used in spells for protection, as well as to break curses and hexes. reference