Of all of the gardening hacks on the web, Epsom salt must be probably the most pervasive. It was entrenched within the gardening trade lengthy earlier than “going viral” was a factor – a longtime a part of gardening folklore. However are you able to apply Epsom salt to your hydrangeas, or will it harm them?
This compound, magnesium sulfate, is really useful for thus many points within the backyard that it’s exhausting to maintain monitor. It’s claimed to enhance progress and flowering, act as a fertilizer, deter pests and illnesses, and resolve varied progress issues.
Nonetheless, while you search for the science to again up these claims, you’ll discover proof suspiciously absent. In the event you’re questioning whether or not a scoop of Epsom salt can resolve all of your hydrangea issues, you’ve come to the suitable place.
The Brief Reply
Except your soil is poor in magnesium (or inhibits the uptake of magnesium), Epsom salt is dangerous for hydrangeas. It doesn’t change soil pH and, by extension, flower colour, or enhance flowering with out deficiencies current. It additionally doesn’t deter pests and illnesses. Even when there are deficiencies in your soil, there are much better strategies of boosting general soil well being. It’s finest to maintain your Epsom salt within the residence and away out of your vegetation.
The Lengthy Reply
Epsom salt, or magnesium sulfate, is a chemical compound containing magnesium, sulfur, and oxygen (MgSO₄). It’s named after a city in Surrey, England – Epsom – the place it was initially found within the pure mineral waters (which additionally explains why the ‘Epsom’ is at all times capitalized).
Magnesium sulfate has a number of attention-grabbing makes use of throughout varied industries. Its excessive magnesium content material makes it a well-liked selection for relieving sore muscle groups.
It’s typically added to bathtub salts with soothing perfume oils. Some folks use it as a pure treatment for stress, insomnia, and even sunburn.
Within the gardening world, Epsom salt is usually used as a complement with the objective of bettering plant progress. In truth, it is likely one of the most broadly really useful “different” soil amendments that I get requested about. This ubiquity has made the substance a typical addition to the software equipment for a lot of gardeners.
Why Do Gardeners Use Epsom Salt?
Epsom salt accommodates magnesium and sulfur, two important secondary vitamins for vegetation. Secondary vitamins aren’t required in excessive quantities like macronutrients (nitrogen, phosphorus, and potassium). Nonetheless, they’re nonetheless important to general plant well being.
Magnesium performs an important half within the formation and functioning of chlorophyll. That is the part chargeable for vegetation’ inexperienced colour and their means to outlive. It aids in photosynthesis, serving to vegetation convert daylight into vitality or “meals” for progress. That additionally implies that the dearth of it might lead to stunted progress, together with different points like yellowing leaves.
Sulfur can be a secondary nutrient important for general plant progress. It helps produce important plant proteins and amino acids and in addition helps with chlorophyll formation as magnesium does.
On condition that Epsom salt accommodates two vitamins important in plant progress and survival, it turned a fast and straightforward method for gardeners to complement these vitamins when deficiencies are detected.
However that’s not the place the makes use of stopped. As gardeners continued to advocate Epsom salt, claims that it aids germination, boosts flowering, and even makes flowers extra vibrant started to emerge. Regardless of the dearth of scientific proof to again up many of those claims, it was touted as a panacea for a lot of gardening ills.
Epsom Salt and Hydrangeas
Though Epsom salt’s supposed makes use of are fairly basic, a couple of makes use of are particular to hydrangeas, from flowering to pest management. Sadly, as with the opposite advantages talked about, the science doesn’t fairly match up with the beliefs.
Altering Flower Colour
Hydrangeas are broadly recognized to change colour based mostly on the soil’s pH degree. Not all species have this means, however some Hydrangea macrophylla and Hydrangea serrata varieties do, making them broadly sought-after. Whereas this seemingly magical change is fascinating, the usage of Epsom salt does little to affect it.
Hydrangea flower colours (in species that change colour) rely on the provision of aluminum ions within the soil. The soil pH immediately influences aluminum availability. In acidic soils, aluminum ions are available, inflicting the flowers to be blue. In alkaline soils, aluminum turns into much less obtainable to the plant, leading to pink flowers.
Magnesium sulfate provides magnesium and sulfur to the soil. Nonetheless, neither of those components has a big sufficient impression on the soil’s pH degree or influences the provision of aluminum in small quantities. Due to this fact, utilizing Epsom salt received’t have any impression on flower colour.
In truth, including an excessive amount of magnesium (which hydrangeas don’t actually require in excessive quantities) might probably result in an imbalance in soil vitamins, making it even tougher for the hydrangeas to entry the aluminum they should produce blue flowers.
The decision: Epsom salt doesn’t change hydrangea flower colour.
If Epsom salt can present key vitamins in progress and flower manufacturing, it is smart to imagine that including Epsom salt to the soil round your hydrangeas can increase flowering. However in apply, it’s not that easy.
Hydrangea flowering is just not primarily depending on magnesium or sulfur, the 2 principal elements of Epsom salt. In different phrases, including greater than needed of both of those vitamins is not going to encourage the plant to push out extra flowers.
Nonetheless, magnesium and sulfur do play an necessary function in general plant well being, as talked about. Your hydrangea will flower to the most effective of its means if they’re current in adequate quantities to maintain the plant completely satisfied and all different circumstances are good. But when sulfur or magnesium, specifically, are poor, replenishing these vitamins will enhance hydrangea well being, subsequently bettering flowering.
However there’s a catch. Backyard soil often accommodates sufficient of those secondary vitamins to maintain hydrangeas happy. Even when there may be sufficient magnesium within the soil, an extra of phosphorus can restrict the quantity vegetation can soak up, resulting in an assumption that magnesium is the issue when it is probably not. The one technique to know for positive is to conduct a soil take a look at.
If a soil take a look at reveals your soil is poor in magnesium, making use of Epsom salts could assist quickly enhance circumstances to spice up flowering. Nonetheless, if there is no such thing as a deficiency, Epsom salt may have no impact on flowering. Even when there’s a deficiency, it’s much better to enhance the general soil well being with natural matter like compost than frequently including salts for short-term outcomes.
In truth, utilizing Epsom salts on hydrangeas long-term could also be counterproductive, resulting in disappointing flowers slightly than prolific ones.
The decision: Epsom salt could enhance flowering if soil is poor in magnesium, however there are higher methods to enhance deficiencies that contribute to general soil well being.
Deterring Pests And Ailments
On the earth of pest and illness delusion and legend, it appears there may be nothing Epsom salt can’t do. Some consider it’s a deterrent for slugs and beetles, whereas others assume it might keep at bay fungal illnesses. Just a few pests and illnesses can plague hydrangeas, so you might be contemplating Epsom salt as a protection.
Sadly, like many unfounded claims, the concept Epsom salt deters backyard pests is basically anecdotal. The idea was doubtless handed down from gardener to gardener with out a lot scientific proof to again it up.
Slugs supposedly despise magnesium sulfate, however they don’t usually have an aversion to both magnesium or sulfur. Perhaps the ‘salt’ within the identify led to this perception, spreading broadly regardless of an absence of proof. In actuality, most pests are extra influenced by environmental circumstances like temperature, moisture, and the provision of their most popular meals than by Epsom salt.
Concerning illnesses, it’s true that sulfur is utilized in some fungicides. Nonetheless, these merchandise usually include sulfur in a unique kind and in a lot greater concentrations than you’d discover in Epsom salt. To fight a fungus downside, commercially obtainable fungicides or natural options are your finest choices.
Making use of Epsom salt in massive quantities can even result in a possible overabundance of magnesium, inhibiting the uptake of different important vitamins. This will depart vegetation extra vulnerable to illnesses slightly than defending them.
The decision: Epsom salt as a barrier towards pests and illnesses isn’t scientifically substantiated and might be probably detrimental.
As a lot as we’d like fast fixes and backyard hacks to be true, Epsom salt doesn’t provide the outcomes hydrangeas gardeners hope for. It doesn’t change the bloom colour, promote greater flowers (except there’s a magnesium deficiency within the soil), or deter pests. Overuse may even be dangerous, resulting in a buildup of salts within the soil that may end up in harm to the plant’s root system and impairing of nutrient absorption.