Smarter Foliar Sprays: A Proven Way to Boost Coverage and Results

Surfactants can also be known as wetting agents, though this term is more commonly associated with soil drenches used to improve water penetration, especially in hydrophobic oils.

In this article, we’ll explore how surfactants work, when and how to use them, and why the right choice can make a major difference to your plant health and foliar spray results.

Why Use a Surfactant in Foliar Sprays?

To boost the effectiveness of fertilisers, plant boosters, pesticides or fungicides when applied directly to foliage.

The challenge is water has a high baseline surface tension of ~72 dynes/cm and has a tendency to cause droplets to bead and roll off leaves, especially those with waxy or water-repellent coatings. Some advanced surfactants— like organosilicones — can reduce surface tension to below 25 dynes/cm allowing sprays to spread rapidly and thinly — almost like a gas — across the entire leaf surface. More about different types further below.

HOW DO SURFACTANTS WORK?

Surfactants break the surface tension of water. The PRIMARY BENEFITS are:

1. Spray droplets don’t bead up or roll off;
2. A smooth, even film forms that better spreads across the leaf - including undersides and hard-to-wet surfaces;
3. Better adhesion to the leaf surface.

This leads to more complete and longer-lasting coverage, improving the chance for nutrients or active ingredients being absorbed efficiently through the leaf cuticle.

SECONDARY BENEFITS:

When using a dedicated oil-based surfactant like Endorse, there’s the added benefit of smothering and suffocating soft-bodied insects and their eggs, as well as suppressing surface-borne pathogens — including bacteria and fungal and mould spores responsible for powdery mildew, downy mildew, rusts, rots, wilts and leaf spot.

If you're foliar spraying with a premium fish-based product like UGF6in1, its natural oily content already helps improve spread, adhesion and thwarts pests & disease. But for maximum coverage, longevity and added pest/pathogen suppression, combining it with a suitable oil-based surfactant like Endorse can significantly enhance results.

Watch below how Australian Gardener of the year - Charlie Smith applies UGF as a foliar and achieves his best ever championship winning blooms...

HOW TO CHOOSE A GOOD SURFACTANT

Common types of surfactants include:

• Basic (ionic) surfactants such as soaps and detergents can drop baseline surface tension of water (75 dynes/cm) to about 35-40 dynes/cm, which means more spread, though may be troublesome, partly due to carrying a charge (usually negative).
• Non-Ionic surfactants e.g. spreader oils such as crop oil concentrates (COC) and methylated seed oil (MSO) adjuvants, reduce surface tension to about about 30-35 dynes/cm
• Organosilicone surfactants (also typically non-ionic), can reduce surface tension to below 25 dynes/cm.

When using foliar sprays — especially organic or fish-based treatments like UGF6in1 — it's important to choose a surfactant that complements the product and enhances performance without causing harm. The best option for most growers is a non-ionic surfactant.

Why Non-Ionic?

Non-ionic surfactants are:

• pH-neutral
• Electrically neutral (no positive or negative charge)
• Gentle on plant tissue, with low risk of leaf burn (phytotoxicity)
• Compatible with organic inputs like fish emulsions, kelp and natural biostimulants.

Because they don’t react with nutrients, minerals, or organic compounds, they won’t trigger nutrient lockout or reduce the effectiveness of your foliar treatment. They simply reduce water’s surface tension, helping your spray form a thin, even film that spreads and sticks — instead of beading up or running off.

For natural-based products like UGF6in1, that’s exactly what you want: better leaf contact, better uptake and fewer complications.

HOW TO MIX SURFACTANTS FOR FOLIAR SPRAYS

Whilst different surfactants may have their different mixing guidelines, here are some general suggestions.

1. First, dilute your foliar treatment (e.g. fertiliser, booster, or pesticide) with clean water and mix thoroughly.
2. Add the surfactant last. Premium oil-based surfactants are best mixed vigorously, shaken if practical, whereas soap-based surfactants are best stirred gently to avoid foaming.

💡 Pro Tip: Perform a Jar Test

Before mixing large volumes, do a small jar test:

• Add your treatment to water.
• Then add the surfactant.
• Observe for any signs of separation, clumping, or precipitation.

If the mix remains stable and uniform, it’s generally safe to spray — ideally as soon as possible after mixing.

⚠️ Important Note on Shelf Life

Some foliar treatments — especially natural or organic products like fish-based fertilisers — may start to break down or even ferment if left sitting in diluted form for too long. Over time, the solution could change chemically or biologically, particularly in warm and ‘lively’ conditions.

To be safe, consider extending your jar test over 24–48 hours to check for changes in smell, clarity, or consistency before storing mixed solutions for future use.

When preparing UGF6in1 for foliar spraying, be sure to shake or stir the concentrate well then dilute with water at a minimum rate of 1:40, though ideally 1:100 or better still 1:200 if practical for even more complete coverage. Best sprayed within a few hours of mixing.

Cautions and Phytotoxicity

• Be sure to read instructions of all products
• Test on a small area before full application
• Avoid extreme heat especially with full summer sun, which may increase burn risk
• Observe plants post-application; reduce rates if sensitivity appears.

HOW TO APPLY FOLIAR FEEDS with SURFACTANTS

SPRAYING METHOD

For best results, aim for complete leaf coverage, including both upper and lower surfaces.

• Start by spraying upward to coat the underside of leaves, where many pests and nutrient absorbing stomata are located.
• Then spray downward over the top to ensure full coverage.
• The finer the mist normally the better, which allows the surfactant to form a thin, even film and minimises runoff.
• If it’s windy or misting isn't practical, a regular spray will still work — the more thorough and even the application the better.

💡 Tip: Avoid spraying in extreme heat, especially in full summer sun, to reduce the risk of leaf burn.

WATERING CAN METHOD

• Fit a rose nozzle with smaller holes to help narrow and diffuse the stream.
• As you pour, gently shake the can side-to-side to help spread the solution and improve leaf contact.
• Target the leaf canopy, not just the base of the plant, for foliar uptake.

Recommended Example: ENDORSE™ Spreader Oil

Endorse™ is a premium oil-based, non-ionic surfactant designed specifically for foliar application. It goes beyond basic spreaders by offering:

• Superior coverage — even on waxy or hard-to-wet leaves
• Longer retention on foliage, helping nutrients stay in contact longer
• Additional smothering effect on soft-bodied pests, their eggs, and fungal spores
• Enhanced performance when mixed with biological inputs like fish emulsion or kelp extracts

Because Endorse is oil-based, it also provides an extra layer of protection, helping suppress common surface-borne issues like powdery mildew, rusts, rots and leaf spots.

🧪 While UGF 6‑in‑1 already contains some natural oily components, adding Endorse™ has been found to significantly boost coverage, consistency and efficacy — especially in warm or dry conditions where sprays can evaporate quickly or struggle to stick.

Where can you buy Endorse™? https://www.AgriWestRural.com.au is a supplier of Endorse, with plenty of knowledge and experience to share.

Please note: NGI is not incentivised by the manufacturer or suppliers of Endorse™. Our recommendation is based on feedback from our customers and our own experience.

PROVEN IN THE FIELD: How Top Growers Use UGF6in1 & Surfactants

At NGI, we’re always evolving. While we base everything on solid science, we also learn a lot from hands-on experience — both our own and that of expert growers around Australia. Some of the most impressive results come from those who've mastered their foliar spray techniques — and their real-world experiences and ours help us fine-tune the advice we share. Here’s how UGF6in1 (paired with the right surfactant) is delivering serious results in real growing conditions.

Acknowledgement to Professional Flower Growing Veteran, Gerard Oldfield of Highland Dahlias in Southern Highlands, NSW for sharing his experiences in spraying out NGI’s UGF6in1 Instant Plant Booster. Gerard is 16-times most successful exhibitor at The Sydney Royal Easter Show and President of Dahlia Society of NSW & ACT explains:

1. Whilst he has a lot of experience growing, supplying, breeding and exhibiting flowers, he was surprised at just how much faster and more plentiful my flowers grew, plus their added health, vigour, colour, shelf-life and tuber retention along with less pest and diseases.
2. He’s experimented and learned to apply UGF6in1 as a root drench prior to planting, then focussing more as a foliar spray upon early shoot then throughout the season for faster, more effective results.
3. Whenever Gerard applies an insecticide treatment, he also includes UGF6in1. “A little often” he says is best for more consistent stimulation.

4. After talking with Tally Matthews, Agronomist of AgriWest Rural Supplies, Gerard tried Endorse Spreader Oil whenever foliar spraying UGF6in1 and other treatments. He explains this helps achieve greater, more even coverage and stickability of UGF6in1 plant feed and other treatments for greater uptake with the added bonus of smothering insects, insect eggs and spores of pathogens.

Acknowledgement also to established exhibitor, Allan Harvey, who explains that using UGF6in1 and combining it with Endorse Spreader Oil has been a game-changer for him. A considerable factor in multiplying his grand champion blooms!

After learning the above, Brett Bramble of NGI also tried adding Endorse when spraying his UGF6in1 onto his dahlias and other plants (normally every 1-2 weeks). Brett finds that diluting UGF6in1 with water at the rate of 1:200 allows him to cover all foliage with the desired rate of UGF6in1 (concentrate) per plant. Plus adding Endorse at 3ml/L better ensures more spread and an even film (without beading). The foliage on his Monstera Deliciosa (large leaf ornamentals) just glisten!