This is the secret weapon gardeners use to make their gardens flourish – experts say it’s the key to healthier roots, soil and growth

We all want beautiful, blooming gardens but if you really want flourishing growth this season then listen up, because garden experts have revealed their secret weapon when it comes to creating the best plant growth.

You may have spent hours putting your garden ideas but there’s nothing worse than them falling flat with wilted leaves and dull blooms - but as a way to prevent this, garden experts want you to add seaweed to your plants and watch your garden flourish.

Seaweed (yes seaweed) is packed full of helpful nutrients - some of which are not in standard fertilisers - which can support better soil health, plant growth and a better root system. This is everything you need to know.

How does seaweed benefit garden plants?

‘Seaweed is good for plants as it contains many useful plant nutrients, such as nitrogen, potassium, phosphate and magnesium. It is also rich in trace elements that are not usually found in common fertilisers, such as copper, zinc and manganese,’ explains Graham Smith MCIHort, a gardening expert from LBS Horticulture.

There are plenty of natural fertilisers that experts swear by, but seaweed has to top the list. It’s nutrient-rich and well-suited to most plants - for example, it widely regarded as one of the best materials for making your own rose fertiliser.

‘Flowering plants, particularly roses and hydrangeas, respond well to seaweed, producing more vibrant blooms and stronger stems,’ says Angharad James, product manager at Maxicrop.

‘Similarly, fruiting plants, including tomatoes and strawberries, benefit from the natural hormones in seaweed, which promote better fruit set and improved disease resistance.

‘Whether in beds, borders, or containers, seaweed is a versatile and sustainable way to support plant health, making it a valuable addition to any gardener’s routine.’

How to use seaweed in your garden

You can use clumps of brown seaweed on your plants but should not be used to replace fertiliser. Instead, we recommend using a seaweed-based fertiliser which achieves both jobs. This is because you cannot take seaweed from the beach in the UK.

‘There is no public right to take seaweed from the beach unless you own the beach and it is not deemed a site of special scientific interest or an area of conservation. If you want to gather seaweed, you will need to consult the land owner or local council,’ says Graham.

'Dried seaweed fertilisers usually include seaweed meal, powdered seaweed extract or liquid seaweed extract. There are also fortified seaweed extracts that have added nitrogen, phosphorus and potassium, and will show the ratio of these nutrients on their label. Many common fertilisers now contain seaweed extract, so you can combine the benefits of fertiliser application with that of seaweed,' he adds.

‘However, seaweed fertiliser does not necessarily work with all plants. Sensitive plants like orchids should be given seaweed fertiliser diluted (especially liquid fertiliser), as should young seedlings. Similarly, plants that have specific nutritional needs, such as azaleas needing acidic soil, may need additional fertiliser alongside seaweed. Despite this, seaweed fertiliser is generally safe for the majority of plants.’

Have you been convinced? I know I will be adding seaweed fertiliser to my garden borders - will you be joining me?