Can Epsom Salt Help Keep Marigolds Blooming From Fall Into Winter?

If you're trying to keep your marigolds (Tagetes) blooming long after everything else has started to fade, Epsom salt might be just what you're looking for — operative word: might. Simply put, Epsom salt is magnesium sulfate, a mineral that helps plants make chlorophyll, turn sunlight into energy, and maybe even show off a few extra blooms. The low soil temperature and cooler weather of the fall can cause magnesium deficiency to occur. A little diluted Epsom salt can sometimes nudge plants into producing more flowers and staying nice and green for longer. But will it work for your marigolds? That really depends.

When magnesium runs low, plants show it in a bunch of ways. Leaves turn yellow between the veins, growth slows, stems get weak, and flowers may struggle to open or look droopy. Marigolds are no exception. Magnesium essentially powers a plant's energy engine, helping leaves capture sunlight and turn it into food. Without it, everything from leaf color to flower power takes a hit.

That's where Epsom salt takes center stage. If your soil is crying out for magnesium, a little boost can sometimes perk up marigolds. But while Epsom salt could be the cure for your marigold's magnesium deficiency, there's a caveat: too much can actually backfire, so a little caution goes a long way. When used wisely, this simple trick can help you enjoy the many benefits of planting marigolds in your garden, keeping your blooms healthy and a lot happier throughout the season.

If you're going to try Epsom salt, keep it simple: dilute it in water (about 2 tablespoons per gallon) and use it sparingly, no more than once or twice a month. You can spray it directly on leaves in the morning or evening, or pour it around the base of your plants. Foliar sprays are usually the quickest way for magnesium to reach the plant, but if your soil already has enough, skip the drench. Be sure to test your soil first for deficiency before embarking on this bloom-saving escapade. Also, check your plant's care instructions for any do's and don'ts.

Remember, Epsom salt is just a supplement; not the main solution. Even though marigolds are relatively low-maintenance, they still need basic care. Hardy in USDA Hardiness Zones 2 through 11, marigolds like their soil on the drier side, so let it almost dry out between waterings. During really hot spells or dry stretches, give them a good drink, but don't let the soil get soggy. Always water at the base of the plant—wet leaves can invite powdery mildew and other fungal issues. Mulch around the roots helps retain moisture and keeps weeds at bay. Once your marigolds are well-established, they can handle a little drought, but they'll reward you with more blooms if watered about once a week.