It Triggers Deep-root Water Hunting
Seaweed contains natural plant hormones – known as auxins and cytokines. When these are applied to grass or flower beds, they send a chemical signal to the plant to kick start specific processes.
Auxins stimulate new growth at all growing tips - be that roots or leaves - and help with cell elongation in these places. Cytokinins promote feeder root growth which means the plant will take up more nutrients and strengthen its immune system - making it more resilient to stresses like heat, drought and disease.
It Keeps Plant Cells Working in Drought Conditions
Seaweed is packed with unique molecules called Osmoprotectants. In simple terms, these molecules act like tiny biological anchors inside the plant's cells.
When a plant is stressed by drought, its cells naturally lose water to the dry air, causing them to deflate and wilt. Osmoprotectants stabilise the fluid inside the cells, keeping the cell walls firm and pressurised even when water is scarce. This stops your lawn or border perennials from completely collapsing under the baking sun.
It Prevents Dehydration
Plants ‘breathe’ and cool themselves through tiny, microscopic pores on their leaves called stomata. During a severe heatwave, a plant can accidentally sweat out all its water and dehydrate.
Recent studies show that treating a plant with seaweed extract alerts its stress-response genes, allowing it to close its stomatal pores much more efficiently (and quickly) during the hottest hours of the day to lock in moisture, and then open them rapidly to recover once temperatures drop.
It Helps Plants Hold on to Water
The benefits aren't just inside the plant; seaweed changes the soil structure too. It contains alginic acid (alginates). When these compounds mix with the soil on your lawn or borders, they bind with tiny soil particles to form a microscopic, crumbly gel matrix.
This gel holds onto water molecules instead of letting them instantly drain away or evaporate out of baked, hydrophobic (water-repelling) earth.
It Contains a Fast-Acting Food Source for Soil Microbes
When the ground bakes, the invisible ecosystem in your soil - the bacteria and mycorrhizal fungi - can dry out and die off. This is a massive blow to your plants, as these microbes are the ones that dig up nutrients and hand them over to the roots.
Seaweed is rich in complex carbohydrates like laminarin, which act as a premium, fast-acting food source for these beneficial soil microbes. By keeping the microbe population fed and active during a drought, you ensure that the soil remains alive and porous. This makes it easy for your lawn and borders to bounce back the moment the rain finally returns.
In addition to these amazing drought-battling compounds, seaweed is also a good source of nitrogen, containing up to 1.5% in its raw form.
But it is the balance of all the other nutrients that makes seaweed so special. It is environmentally friendly and sustainable, making it an excellent choice for organic growers.
While applying seaweed is never going to give you an abundance of top growth, it will promote an overall healthier plant that is greener, and far more likely to survive drought or the onset of disease.
Lawns will look thicker and lusher, ornamental plants will have shinier leaves and more abundant flowers, and fruit will set on trees and bushes far better.
Here at Agrigem, we supply one of the best-selling seaweed extracts available for plant health – Emerald Pro. But we also offer a granular calcified seaweed produced from naturally occurring calcified algae and seashells. This helps break down heavy soil and improve its structure.
Abzorb Wetting Agent Tablets also contain seaweed extract – giving you all the benefits of seaweed with the added functionality of a wetting agent – to help improve water retention, mobility and drainage.
Now you know the amazing benefits of seaweed, we recommend you apply it now to help your turf and plants through this bout of very hot, dry weather. Emerald Pro is safe to use on grazing grass too.
This guide was written in collaboration with Ollie Wright.
Ollie Wright MBPR, FQA
Ollie Wright serves as the Technical Manager at Agrigem, where he oversees the integrity and accuracy of the company’s technical output. A recognised figure within the UK turf-growing sector, Ollie leads Agrigem’s technical response, ensuring that all guidance provided to retail and trade clients remains rigorous, compliant, and at the forefront of industry standards.
With a career built on a foundation of practical experience in farming and landscaping - including the successful management of his own firm - Ollie bridges the gap between theoretical science and field application. His extensive hands-on background is reinforced by industry credentials, including RHS Horticulture, amenity turf and hard surface BASIS, and FACTS qualifications. This unique combination of expertise allows him to deliver high-level strategic advice across diverse sectors regarding plant protection products and complex legislative requirements.
Article Notes:
Abzorb and Emerald Pro are trademarks of Agrigem Ltd.
Use plant protection products safely. Always read the label and product information before use. For label and safety information, refer to the manufacturer’s website.
Only certified users may apply professional plant protection products. Find out more about safe use of pesticides here.
