Boost Plant Growth: 8 Amazing Plants That Thrive on Epsom Salt

I adore plants, and over the years, I've picked up all sorts of tips to help them thrive. One of my favourites? Epsom salt. It might surprise you, but this simple, affordable remedy can boost certain plants, especially when they're struggling with magnesium deficiency.

Let’s explore how it works and which plants actually love a sprinkle of it.

Boost Plant Growth: 8 Amazing Plants That Thrive on Epsom Salt

What Is Epsom Salt—and Why Use It?

Epsom salt isn’t salt—it’s a naturally occurring magnesium and sulfate mineral compound. Magnesium plays a vital role in photosynthesis and helps plants absorb nutrients like nitrogen and phosphorus more efficiently.

If your plants have yellowing leaves, poor flowering, or just seem lacking, they might be craving magnesium.

8 Plants That Love Epsom Salt

Here are some popular garden and houseplants that benefit from the occasional dose of Epsom salt:

1. Tomatoes

Tomatoes are magnesium-hungry! Epsom salt can help prevent blossom-end rot and boost fruit production. Add 1 tablespoon per litre of water and spray every couple of weeks during the growing season.

2. Peppers (Chilli & Sweet)

Just like tomatoes, peppers benefit from regular magnesium. Use a soil soak or foliar spray monthly.

3. Roses

Are you struggling to get lush blooms? Add a tablespoon of Epsom salt to the soil around each bush every month.

4. Houseplants (Especially Ferns & Palms)

Indoor plants like ferns, palms, and rubber love the occasional magnesium boost. A diluted spray can perk up dull foliage. Bonus tip: if they're in a concrete pot, ensure the drainage is good to avoid build-up.

5. Lemons & Citrus Trees

Magnesium deficiency shows quickly in citrus plants. Use Epsom salt monthly as a soil drench or light foliar mist.

6. Geraniums

Encourage brighter blooms and healthier leaves with a small dose of Epsom salt every few weeks.

7. Hydrangeas

They’re sensitive to soil nutrients. Epsom salt supports leaf health and vibrant colour, especially if your soil lacks magnesium.

8. Carrots & Root Vegetables

Improve root development and flavour by mixing Epsom salt into your watering routine during early growth.

A Note on Indoor Pots & Concrete Planters

Allow proper drainage if you're using concrete pots (like many of mine). Although Epsom salt is water-soluble, salts can accumulate in containers over time if excess water can’t escape.

I always recommend:

• Using pots with drainage holes

• Adding a tray or pot feet underneath

• Flushing your soil occasionally with plain water

How Often Should You Use It?

• General guide: 1 tablespoon per litre of water, every 2–4 weeks

• For potted plants: Reduce frequency—once a month is usually plenty

• Foliar spray: Apply early morning to avoid leaf scorch

Epsom Salt For Plants: Final Thoughts

Epsom salt isn’t a magic fix for every plant, but for the ones that love it, the difference is clear—healthier leaves, stronger roots, and more vibrant blooms.

I use it sparingly and with intention, and it’s become a simple staple in my plant care routine. Give it a try and see how your plants respond!

Frequently Asked Questions

1. Can I put Epsom salt directly into the soil? You can sprinkle it directly into the soil—mix it well and water afterwards. For most plants, 1 tablespoon per 30 cm of plant height every few weeks is a good guideline.

2. How do I know if my plant needs magnesium? Look out for yellowing leaves with green veins (especially older leaves), weak growth, or poor flowering. A soil test can confirm a magnesium deficiency.

3. Can I use Epsom salt on all houseplants? No, only certain plants benefit from it. Avoid using it on succulents or cacti; they don’t typically need extra magnesium and can suffer from overwatering and salt build-up.

4. Is Epsom salt safe for seedlings? Use with caution. Young plants are sensitive, so dilute it further (½ tablespoon per litre) and avoid applying too often.

5. Can I mix Epsom salt with other fertilisers? Yes, but check the magnesium content of your fertiliser first. If it already contains magnesium, you might not need to supplement at all.