Low on Magnesium If your gardenia needs magnesium, this will cause the leaves to turn yellow. You can remedy this with a fertilizer high in magnesium, or you can add some Epsom salts to your soil. Mix one teaspoon to one gallon of water and apply every two to four weeks.
Give the plant a boost (and maybe return some green to yellow leaves) by applying magnesium sulfate or Epsom salts. Mix a tablespoon of either in a gallon of water and sprinkle around the plants. Thrips – about one-sixteenth of an inch long – love gardenias.
Adding Epsom salts, or magnesium sulfate, is supposed to replenish the missing magnesium, perking up the gardenia in the process. Some gardeners recommend a one-off dosing, others a feed at regular intervals.
A. Gardenias are evergreen but still drop leaves. The yellowing is caused by a lack of magnesium. We suggest feeding with Tui Enrich Rose, Camellia, Azalea & Gardenia controlled release fertiliser in early spring and late summer, and applying Tui Organic Seaweed Plant Tonic regularly.
If your plant's leaves are turning yellow, it might have a sulfate deficiency. If your plant's leaves are turning yellow but the veins remain green, it might have a magnesium deficiency. Epsom salts are a great solution for both of these problems.
Verdict: Unless you have a magnesium deficiency in your garden, there is no need to add Epsom salts. Doing so could even be harmful to soil, plants and water. Find out more about healthy soil and getting a soil test.
Epsom Salt for Plants
It's also said to help seeds germinate and repel slugs and other garden pests. But unless your soil has a magnesium deficiency, the University of Minnesota Extension Service recommends against adding Epsom salt. Too much can harm your plants and soil.
Feeding and mulching Gardenias are fed during the growing season from spring to autumn with a complete fertiliser such as Seasol plus Nutrients Roses & Flowers. Water it in well after application. Plants also benefit from liquid feed such as PowerFeed PRO SERIES for Roses & Flowers during the growing season.
Most Gardenias flower in spring and summer, so the end of summer or early autumn is generally best. Just make sure the plant is well watered before and after pruning, and feed just after pruning with Yates Dynamic Lifter Soil Improver & Plant Fertiliser.
Gardenias use a lot of nutrients to produce so many glorious blossoms. Feed your shrubs by applying an acidic, slow-release fertilizer such as an azalea or camellia fertilizer. For the organic gardener, blood meal, fish emulsion or bone meal work well.
Sprinkle a teaspoon of Epsom salts around the plant and water in. Iron deficiency first affects new leaves. Apply iron chelates. Treat both in late spring and again in summer.
Spraying your gardenia with an antifungal agent (such as horticultural oil with baking soda and insecticidal soap) can reduce the risk of infection or infestation.
Frequently Asked Questions. Should yellow leaves be removed from gardenias? Most of the time (especially if the leaves are yellowing due to age), the discolored leaves will fall off on their own.
“Magnesium and sulfur are essential nutrients.” Although magnesium and sulfur occur naturally in soil, they can be depleted by various conditions, including heavy agricultural use. But unlike most commercial fertilizers, which build up in the soil over time, Epsom Salt is not persistent so you can't overuse it.
Liquid seaweed products like Seasol also help to acidify your soil and gardenias really love this. However, to give your gardenias an additional boost, you might like to replace the regular Seasol with either Seasol Plus for Roses and Flowers or Seasol PowerFeed Pro.
Are Coffee Grounds Good for Gardenias? Don't worry about adding more coffee grounds to your gardenia soil; these flowers absolutely love coffee. In addition to being an excellent source of nitrogen, the acid in coffee lowers the pH of the surrounding soil, stimulating the roots of acid-loving plants such as gardenias.
Fertilising Gardenias
Gardenias are heavy feeders and like lots of iron and magnesium. Every 2-3 months from spring to autumn feed with a dose of cow manure and a bit of Certified Organic fertiliser if your soil is particularly poor.
Do not apply Seasol and PowerFeed during the heat of the day. As PowerFeed is a fertiliser it may burn the foliage of the plant or lawn.
You can't overdose on Seasol. It's not a Fertiliser.
Azalea, Camellia, Gardenia, Evergreen Fertilizer 4-8-8
Specially formulated plant food to help produce healthy roots, stems, leaves and flowers on Azalea, Camellia, Gardenia, Evergreens and other acid-loving plants. Can be used with new and established plants.
Epsom salt can improve the blooms of flowering and green shrubs, especially evergreens, azaleas and rhododendrons. Work in one tablespoon of Ultra Epsom Salt per nine square feet of bush into the soil, over the root zone, which allows the shrubs to absorb the nutritional benefits.
For many people, drinking Epsom salt is generally safe. However, those with kidney disease or heart disease, pregnant women, and children should not consume it. A person should speak with their doctor if they are unsure about drinking Epsom salt. People can use Epsom salt as a laxative to treat constipation.