Epsom salts are widely available at pharmacies because of their usefulness as a bodily cleanser. Soaking in Epsom salt is recommended to treat numerous conditions and strengthen your natural resistance to certain illnesses. However, Epsom salts can also be used to revitalise other living organisms; indeed, Epsom salt can be used to benefit plants. According to the Orange County Register, Epsom salt is not technically salt; in other words, it isn't sodium-based. Its main ingredient--magnesium--is known to replenish plant nutrients for stronger, more robust plants.
Read the Epsom salt label to ensure it is pure Epsom salt. The ingredients should indicate whether or not additional materials were mixed with the Epsom salt. Some Epsom salts come with sea salt or other products mixed in, and these compounds can actually damage your garden.
Determine the amount of Epsom salt needed based on how much water you typically use per day. You'll need to mix the salt into your entire supply of water all at once, so keep track of how many full watering cans you use in order to get a good estimate for your required amount of water. According to the Epsom Salt Council, most common houseplants require 2 tbsp of salt for each gallon of liquid used during normal watering. For example, if your houseplants typically soak up 2 gallons of water per day, you'll need to add 4 tbsp of Epsom salt to your normal watering regimen.
Pour your daily amount of gardening water into a large bucket for mixing. Use hot water because cold water does not dissolve Epsom salt as easily.
Mix the required amount of Epsom salt into the bucket of hot water. The solution is thoroughly mixed when all visible grains of salt have disappeared, completely dissolving into the water. The water does not need to be boiling hot, but should be above room temperature. Typically, using hot water directly from a standard kitchen hot-water tap will work well.
Wait for the water to cool to room temperature since most plants thrive best on cool water.
Stir the solution again; some of the dissolved salt will have settled on the bottom and you need to redistribute it throughout the mixture.
Fill a watering can with the Epsom salt solution and water your plants with your usual amount of water. Refill the can as needed until you have watered all your plants with the Epsom salt solution.
Repeat daily for the best results. Epsom salt cannot be overused, according to the Epson Salt Industry Council, as cited by the Orange County Register, so water with it regularly to ensure healthy, robust plants.
The procedure for applying the salt differs if you're using Epsom salt to revitalise tomatoes or roses. For tomatoes and roses, do not mix Epsom salt into your routine watering. Instead, dry Epsom salt should be applied to the topsoil, near the plant's base. For tomatoes and roses, use 1 tbsp of dry Epsom salt for every foot of plant.