5 plants that like eggshells – the calcium lovers that benefit from this overlooked kitchen scrap

Did you know that some plants like eggshells? It sounds bizarre, but it actually makes a lot of sense once you understand their nutritional value to certain plants.

There are a few ways to use eggshells around the garden, but turning them into fertiliser isn't something you'd expect to work. If you clean them and finely crush them up, though, they’re a fantastic source of calcium – and I didn’t realise just how many plants can benefit from them.

‘Before using eggshells in the garden, make sure they're thoroughly cleaned to remove any egg residue that could attract pests,’ advises Nick Wood, horticulturist at GardeningExpress.co.uk. ‘Once they're completely dry, crush them into a fine powder so they break down quickly and can be absorbed by root systems easily.’

Here’s a list of plants that like eggshells.

1. Tomatoes

Learning to grow your own tomatoes doesn’t usually come with notes on feeding them eggshells, but experts say they can actually provide a nutrient boost and bolster your plant’s defences early in the season.

‘Eggshells are best used with crops that appreciate a bit of calcium, especially tomatoes,’ says Julian Palphramand, head of plants at British Garden Centres.

‘For tomatoes and peppers, eggshells are often used as part of the approach to reducing blossom-end rot, but they’re not a cure on their own. They work best alongside even watering and a balanced feed.’

It’s a little late in the year for eggshells to have a meaningful effect on your tomato plants, since they take a bit of time to break down in the soil, but it’s worth saving your kitchen scraps next year. In the meantime, a fertiliser like Levington Tomorite, which you can order for just £3.99 from Amazon, can give your plants the late summer boost they need to produce lots of tasty tomatoes.

2. Squash

I think squash is one of the most rewarding crops I’ve ever grown – patty pan squashes were a hit in my small vegetable garden – and it’s another plant that loves eggshells.

‘Eggshells are a great addition to the garden because they're rich in calcium carbonate,’ says Nick. ‘Plants that benefit from extra calcium, like squash, can make good use of them.’

For a bumper crop, don’t forget to feed your squash plants with a fertiliser that provides a steady supply of essential nutrients. This Bronte Heritage Collection Courgette, Squash & Pumpkin Feed (available from Amazon), for example, is specially formulated for rapid fruit development and swelling.

3. Leafy greens

Salad crops like spinach and lettuce also appreciate an occasional dose of crushed eggshells. Julian says they’re another example of plants that benefit from calcium, which makes them brilliant candidates for eggshells.

‘The trick is to crush them finely first,’ says Julian. ‘Otherwise, they break down too slowly to make much difference in the short term. I’d use them as a light top dressing, mix them into the soil, or add them to compost rather than expecting them to work like a quick feed.’

As Julian mentioned earlier, eggshells should never replace well-rounded feeds. A general-purpose fertiliser like Westland Organic Vegetable Liquid Plant Food from Amazon will give you better results.

4. Clematis

Those vegetables aren’t the only plants that love eggshells – climbing plants like clematis prefer a slightly alkaline soil, and crushed eggshells can lift the soil’s pH level a little.

‘Crushed eggshells are best used around plants that prefer alkaline soil, as they slowly release calcium and can raise the soil's pH,’ says Nick. ‘Flowering plants like roses appreciate the boost.’

Of course, you’ll need to feed your clematis other nutrients for them to perform their very best. Vitax Clematis Feed, which you can order from Amazon, can be used every three months from March to promote vigorous growth and flowering.

5. Aubergines

As their matching names would have it, eggshells and eggplants work really well together. They’re another suggestion of Julian’s, since eggshells stave off blossom-end rot in aubergines in the same way they would for tomatoes and peppers, and they’re also calcium-loving plants.

‘They’re also a really great deterrent for slugs and snails thanks to their sharp edges,’ adds Nick.

There are, of course, some places you should never use eggshells in the garden. Blueberries and camellias, for example, benefit more from being watered with coffee.

‘Try to avoid using them around acid-loving plants, because it will reduce the soil's acidity, making growing conditions less suitable,’ warns Nick.

Shop these popular fertilisers

Are you growing any plants that like eggshells? Make sure you wash them and crush them into a fine powder before you use them as a feed!