Hydrophobic Soil | What is it? How to Fix it with Soil Wetting Agents

What is Hydrophobic Soil?

First of all, what does hydrophobic soil mean? It can happen in most situations, but is mostly found in hotter areas, where the high temperature of the soil causing rapid drying out, which negatively impacts on its organic content.

The main feature of the hydrophobic soil is the inability of moisture to absorb. When water falls on the soil, it runs off the surface, or simply sits there and doesn’t mix.

As organic matter (in particular native leaf litter) breaks down, waxy residues are left behind. More often than not, this isn’t a bad thing, as it either mixes through the soil harmlessly, or is broken down by fungi and other natural processes in the soil.

When the waxy residue builds up and coats the soil particles though, water repellency can occur. The more soil particles coated, the less water that penetrates. 

The lower the surface area of the soil aggregate (like sand, which has less surface area on the soil aggregates than say, clay) the less waxy residue required to coat it.

A simple small experiment with the soil may show whether it’s hydrophobic or not. Just take some soil and pour water onto it. If it doesn’t absorb and just pools there with round edges, you’ve got a problem.

Hydrophobic soil is dangerous for your plants, because in spite of being watered properly, no water reaches the root zone, and your plants can become stressed.

Soil Wetting Agents

How to fix hydrophobic soil? The simplest way to make your soil absorb the water is using wetting agent. These impact on the waxy residues in the same way washing detergents impact grease and fat particles in your washing up.

By reducing the surface tension of the water, the moisture can more easily penetrate the soil particle and get moisture where we need it, and our plants are watered properly.

Soil wetting agents are easily purchased from any nursery or gardening store, are really easy to use and 99% of the time will fix your problem.

Here are some of the best Soil Wetting Agents and Gels we have found.

1. Eco-Hydrate Soil Wetter & Moisture Attractant

If you’re a green gardener and love to use organic, safe products, then this soil wetting agent is the perfect choice. It’s been approved for use in organic gardens and is Australian Certified Organic (ACO), making it safe for use in environmentally sensitive areas.

It’s enriched with fulvic and amino acids as well as seaweed, helping to supply plants and soil microorganisms with essential nutrients.

It’s fully safe for use on vegetable and herb gardens, lawns, native plants, and potted plants.

2. Scotts Everydrop 25L Premium Granular Soil Wetting Agent

If you are looking for a granular soil wetting agent, this is a good option. It can be spread onto all hydrophobic soil and even around new plants, as it will not burn.

It’s made of coir peat (coconut husk) and a soil wetting agent, helping to de-compact clay soils and add organic content to sandy soils.

It’s safe for flower baskets, container plants, vegetable and herb gardens, and any other area of your garden suffering from hydrophobia.

3. Penterra Soil Penetrant and Wetting Agent

Used in gardens as well as on golf courses, crops, and athletic fields, this professional-grade wetting agent helps to restore a healthy soil biome and retain water.

It helps break up heavy clay soils and strengthen plant roots, helping plants get the nutrients and moisture they need through hot or dry spells. The ingredients are earth-friendly too.

4. Yucca Organic Wetting Agent and Surfactant

This organic soil wetting agent is an excellent surfactant, reducing the barrier on hydrophobic soil to ensure good penetration and minimal runoff and erosion.

It’s made from Yucca Schidigera extract and contains 60% saponin, a natural compound that foams and naturally breaks down water molecules for improved absorption.

It’s more evenly absorbed by plants and will not spot the leaves, and it helps protect plants from environmental stress and damage.

5. Soaker Eco Friendly Soil Wetting Agent

This concentrated liquid soil wetting agent is ideal for use on hydrophobic soils in gardens, potting soil mixes, and vegetable gardens. 

As a surfactant, it works to break down the surface tension of water, helping water to soak into the soil. By promoting healthy soil full of beneficial microbes and organisms, this product helps to improve moisture retention over the long-term. 

In this form, you will use 10ml per 1 litre of water, which can treat up to 50 square metres of soil.

6. Hortico Soil Wetting Agent

Containing an effective blend of coir peat (coconut husk) and wetting agent, this product adds vital organic matter to sandy and heavy clay soils with hydrophobic qualities.

The wetting agent is slowly released over time to ensure long-term results, lasting up to 3 months. With increased water retention, you don’t need to water as often – even during the heat of summer – reducing heat stress on lawns, flowers, and vegetable gardens.

7. Seasol 2.5L Super Soil Wetter And Conditioner

This liquid soil wetting agent is aquatic-safe, improves soil water retention, and retains moisture at the root level. It stays active for 3-6 months or more, so is ideal for use over the spring and summer months.

As a soil conditioner, it helps essential microorganisms thrive in the soil, creating a healthy biome for plant growth and optimising nutrient intake into plants and lawns.

It’s Australian-made and is safe for vegetable gardens, fruit trees, and herb gardens.

Our pick as the best soil wetting agent for your garden is the Eco-Hydrate Soil Wetter & Moisture Attractant . It’s organic, safe for use on vegetable gardens, lawns and new plants, and it lasts a good few months between applications, giving you long-term benefits.

It’s the only product on our list that is Australian Certified Organic (ACO), which means it meets the highest standards for environmental sensitivity, making it ideal for native plants.

As a budget-friendly option, Scotts Everydrop 25L Premium Granular Soil Wetting Agent is a great option. It’s very long-lasting too, giving you better moisture penetration and healthier soil for up to 6 months between applications.

These granules are easy to apply, safe and non-toxic to all plant types, and won’t burn your plants.

As a top professional-grade soil wetting agent, Penterra Soil Penetrant and Wetting Agent is our pick for the best premium soil wetting agent. Although it is more expensive than competitors, it’s fast-acting and very effective, helping to green up lawns, boost flowering and yields, and improve plant growth. 

It will flush excess salts from the soil, condition it, and improve the aerification of your soil, giving you great results.

Soil Wetting Agents FAQs

Do Soil Wetting Agents Work?

These products break down the waxy coating on soil particles and reduce the surface tension of the water molecules, so moisture sinks into the soil more easily where roots can access it.

The added moisture in the soil helps promote bacteria growth and other microorganisms that are essential for a healthy soil biome, overall improving the nutrients in the soil, aerification, and overall soil condition.

What is the Best Soil Wetting Agent?

The best soil wetting agent is one that works quickly, improves sandy or clay soils, breaks through water tension to help moisture absorb to root level, and delivers lasting results.

It’s also a good idea to look for a soil wetting agent that is safe for your garden, whether that means it is organic, safe for fruits and vegetables, or safe for new plants.

Can You Use Dishwashing Liquid as a Soil Wetting Agent?

Hydrophobic soil has waxy molecules that cause water to run off, and soap can help break these down. We recommend trying an organic and biodegradable dishwashing liquid to avoid affecting your plants or the environment, mixing 1 teaspoon of the liquid with 3 litres of water.

Are Soil Wetting Agents Safe?

If you have native plants, it is essential that you use an Australia Certified Organic (ACO) product and stick to manufacturer guidelines, as this is the safest option for these sensitive plants.

Other soil wetting agents may not be appropriate for vegetables and other consumables, and some should not be used on new plants or sprayed onto foliage.

Can You Apply Too Much Wetting Agent?

Usually, you cannot damage your garden by applying too much soil wetting agent. Overdoing it simply wastes the product rather than harming the plants.

However, some soil wetting agents shouldn’t be applied to new plants or foliage as this can burn the plant. As always, we recommend following manufacturer instructions for applications, especially if you are using a liquid concentrate.

Prevent Hydrophobic Soil with Good Soil Health

The best way to fix any soil issue, is to keep it happy. Healthy soil will generally not have problems like water repellency. To know more about healthy soil, check out our loam soil guide. 

Working a good, well aged, organic compost through your soil, watering it regularly, and keeping the microbial activity churning along will help reduce any chance of that annoying waxy residue accumulating.

Using soil problems like this is a great excuse to give your garden a bit of love and TLC and get them back to where they need to be for healthy happy plants.

Making sure you have a good soil mix that will also aid in allowing plenty of space between the soil pores for water to infiltrate. Hydrophobic soil isn't great, but it's not the end of the world.