Can you apply too much wetting agent?

Author: Dr. Jada Bayer MD  |  Last update: Thursday, September 18, 2025

Unlike fertilisers that can cause toxicity if applied too frequently or in too large an amount, wetting agents present no such risk. While they won't cause in problems, applying them too frequently is a waste of money – once they have done their job there is nothing more that can be achieved.

How much wetting agent should I use?

Typically, 5-6 oz is used for 30 days, and 2-3 is used for 10-14 day applications. It's fine to mix the wetting agent chemistries with other types (foliars, PGRs, fungicides) provided that you have enough free water in the tank for tank mix compatibility, and you water in the application that night.

Are wetting agents harmful?

The answer is, it depends. Some wetting agents are made from harsh chemicals that can be harmful to the environment and potentially toxic to humans, animals and water courses. However, wetting agents made from biodegradable and environmentally friendly ingredients are available.

How often should you put a wetting agent on your lawn?

Wetting agents can be applied at differing application rates – from annual to monthly or bi-monthly. Therefore, if restrictions on the water are introduced in the summer, then a lawn can still benefit from an annual application. All soil structures have differing capacities for moisture retention.

How long does wetting agent take to work?

How long do wetting agents take to work? You will see results 10 days after wetting agent and water application.

How to fix hydrophobic or water repellent soils with organic wetting agents

Should wetting agent be watered in?

Different types of wetting agents

Soil wetting agents are available as granules, liquid concentrates, and hose on bottles. Most granular and liquid concentrates need to be watered in well, but it is always best to check the product label.

Can you reuse wetting agent?

Wetting agents are essentially just a soap designed to help water evaporate off the film when it's drying. So there isn't that much of a problem with dumping them down the drain — especially after the film has been washed. But wetting agents, because of their simple formulation, can be reused extensively.

How long do wetting agents last in soil?

How long does the wetting agent treatment last? Granular wetting agent treatment can last for up to five months in domestic lawns providing it is applied in the spring when conditions are wet or when it is thoroughly watered in.

Should wetting agent be applied before or after seeding?

For best results, soil surfactants should be applied two weeks before seeding to prepare the soil. A second application is beneficial three to four weeks after seedling establishment to ensure continued soil moisture uniformity.

Is wetting agent necessary film?

While a wetting agent isn't an essential step in developing film, it will make your life much easier when you come to scan or print your negatives. With a high dilution, a bottle will last you a long time. So, we think it's worth the small extra cost.

What is the difference between a wetting agent and a surfactant?

All wetting agents are surfactants, but not all surfactants are wetting agents. Wetting agents are a class of surfactants that lower the interfacial tension of a liquid. An example is water. Water has a high interfacial tension, so a drop of water tends to “bead” on a hydrophobic surface, such as plastic.

What is the shelf life of wetting agent?

Long term conditions in older lawns may need treating every month from April to August (5 applications). This means typically you would need to order enough to treat the total area 3 to 5 times in any one year. This product has a shelf life of 3 years.

Can you spray wetting agent in the rain?

The wetting agent should be applied to the lawn prior to rain or watering. You can apply to the whole lawn which may include some greener areas or just to the dry areas. If applying to dry patches, treat an area slightly larger than the patch itself.

What can I use instead of wetting agent?

You can make your own wetting agent using the same soap you use on your sponge, your hands and dishes.

Is liquid or granular wetting agent better?

Wetting agents come in both granular and liquid forms. Granular wetting agents are best for garden beds and pre-lawn installation, as they can be mixed into the soil. Liquid wetting agents can also be used on garden beds and existing lawns.

What does a wetting agent do to soil?

Wetting agents are often pre-mixed into the potting media and fertilizers and function by reducing water's surface tension, enabling greater uniformity in moisture distribution. By doing so, the use of wetting agents results in greater root development, healthier and more uniform plants, and better water drainage.

Can you put too much wetting agent on lawn?

Unlike fertilisers that can cause toxicity if applied too frequently or in too large an amount, wetting agents present no such risk. While they won't cause in problems, applying them too frequently is a waste of money – once they have done their job there is nothing more that can be achieved.

Does a wetting agent need watering in?

Most will need to be thoroughly watered in and can be reapplied every six to eight weeks, as often as needed to treat water repellent soil. Granular products are usually made up of a carrier medium, such as cork, which holds the soil wetting agent and any other additives, such as minerals and trace elements.

Can wetting agent burn grass?

While it's best to immediately water in the wetting agents upon application, if you do need to leave it for a little while that's okay – wetting agents will not burn the lawn if left like fertilisers will.

Are wetting agents worth it?

They help store more water in the soil for longer, meaning your plant can go longer between being watered. They don't help with hydrophobia; only a good soil wetter will do the job.

Can you use dishwashing liquid as a soil wetting agent?

It's also possible to use diluted dishwashing liquid or dishwater/laundry water as a soil wetter because the surfactants in the detergent break surface tension in water like wetting agents do. However, be cautious when using detergents in your garden and choose environmentally friendly/biodegradable options.

How long does it take to fix hydrophobic soil?

It may take an hour or more to thoroughly re-wet the soil. Be careful not to leave pots soaking in standing water continuously. Check them after an hour or two and remove them when they are hydrated.

What is the mixing ratio for wetting agent?

For General Insecticides, Herbicides & Fungicides:
  1. High Volume Power Spray – 100mL per 100L Water.
  2. Low Volume Boom Spray – 40mL per 100L Water.
  3. Misting Machine – 5mL per 5L Water.
  4. Knapsack – 2mL per 15L Water.
  5. General / Domestic Use – 1mL per 1L Water.

Is surfactant same as wetting agent?

The key difference between wetting agent and surfactant is that wetting agents can reduce the surface tension, allowing the liquid to spread drops to a surface, whereas surfactants can lower the surface tension between two substances. Wetting agents are a type of surfactants.

Is PhotoFlo a wetting agent?

Photo Flo is a wetting agent used to minimize water marks or streaks during film development. It is used after the final wash when processing films to decrease the water-surface tension and promote faster, more uniform drying.

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