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Brix+ liquid seaweed biostimulant with triacontanol and seven growth promoters
7 Growth Promoters Contains Triacontanol 74 Ocean Trace Minerals Foliar & Soil Drench Plant-Based Dr Forest · Stockport
Brix+ is a concentrated liquid seaweed biostimulant that carries triacontanol, cytokinins, gibberellins, auxins, betaines, mannitol and a fraction of natural acids and phenolics, plus 74 ocean-derived trace minerals. Used little and often as a foliar spray or soil drench, it nudges the plant's own growth signalling: more photosynthesis, more sugar in the sap, better root establishment and a buffer against frost, drought and heat.
The name comes from Brix (°Bx), the refractometer reading for sugar in sap and fruit juice. Brix+ is not a primary fertiliser: nitrogen is 0.26% and potassium 1.65%, so it goes alongside a proper feed. Sold in 500 ml and 1 litre bottles; at 2 to 2.5 ml per litre a litre makes 400 to 500 litres of spray.
7Growth promoters
74Ocean trace minerals
2–2.5 ml/LFoliar rate
1.65% KTotal potassium
What a liquid seaweed biostimulant is used for in the garden
- Raising Brix in fruit and vegetables — triacontanol lifts the photosynthetic rate, so the plant makes more sugar per hour of light
- Flowering, fruit set and finish — the cytokinin, gibberellin and auxin signals support flower development and fruit set
- Transplant and root establishment — a 5 ml/L drench at planting out gives the auxin signal and trace minerals to a root system that has just been disturbed
- Frost, drought and heat — a foliar spray immediately before a forecast frost, drought or heat event, or as soon as conditions allow afterwards, to support recovery
- Lawns — a foliar pass every 10 to 14 days for colour and drought tolerance, particularly before a dry spell or after a scorched August
- Roses and ornamentals — bud development, bloom size and flowering period
Why a triacontanol seaweed concentrate rather than a plain seaweed feed?
Brix+ liquid seaweed biostimulant
- Seven named growth promoters, with triacontanol as the lead compound
- Works at 2 to 2.5 ml per litre as a foliar spray
- Low NPK by design, so it adds very little salt and will not push soft, sappy growth
Standard liquid seaweed feed
- Seaweed extract on its own, with no added triacontanol
- Sold as a general tonic
From Dr Forest, Stockport
Brix+ is a plant-based liquid from Dr Forest, Stockport, Greater Manchester, and sits in the same family as our soluble seaweed extract powder. If you want the background on what seaweed does for plants before you buy, read benefits of seaweed fertiliser for plants. Made by Growers. Backed by Science.
The Science
The science of Brix+: triacontanol, seaweed signals and sugar in the sap
What Brix measures
A refractometer reads how much light bends passing through a drop of juice and reports it as degrees Brix, roughly the percentage of dissolved solids. In fruit that is mostly sucrose, glucose and fructose, with acids, amino acids and minerals making up the rest. A tomato at 4°Bx tastes watery; at 8°Bx it is properly sweet. In fruit, the reading is a fair guide to how much sugar the plant has made and stored.
Brix is often sold as a measure of pest and disease resistance as well. The controlled evidence for that is thin, so we leave it out. The research does support two narrower points: triacontanol raises photosynthetic output [2], and fruit from seaweed-treated crops measures sweeter [9].
Typical analysis
| Component | Value | Note |
|---|---|---|
| Natural acids, phenolics, amino acids, 74 trace minerals, cytokinins, gibberellins, auxins, betaines, mannitol | 17.5% | Declared as one combined figure |
| Total nitrogen (N) | 0.26% | Trace; not a nitrogen feed |
| Total potassium (K) | 1.65% | |
| Sulphur (S) | 0.37% | |
| Magnesium (Mg) | 0.15% | |
| pH | 5.0–5.8 | Mildly acidic; jar test before tank mixing |
| Conductivity | 30–50 mS/cm | Concentrate; falls to negligible at 2.5 ml/L |
| Specific gravity | 1.0 | 1 ml weighs 1 g, so ml and g are interchangeable |
| Appearance | Brown liquid | Can mark pale fruit if sprayed near harvest |
The nutrient numbers are deliberately low; a biostimulant is judged on what it signals, and the working strength (2 to 2.5 ml per litre) is a 1:400 to 1:500 dilution. The most widely researched seaweed for plant biostimulants is Ascophyllum nodosum, the North Atlantic rockweed, a rich source of alginic acid (28%), fucoidans (11.6%), mannitol (7.5%) and laminarin (4.5%) [6]. The betaine and hormone fractions are tiny by weight, which is the puzzle of how these products work.
The hormones in a seaweed extract are too dilute to do much on their own; the extract appears to work by adjusting the plant's own supply.
Mechanisms of action
01
Triacontanol raises photosynthetic capacity at nanomolar doses
Triacontanol is a 30-carbon fatty alcohol from the wax of alfalfa and other leaves, reported as a new plant growth regulator by Ries and colleagues in Science in 1977 [1]. A 2012 review in the Journal of Plant Interactions collects the field record: activity at nanomolar concentrations, a roughly 30% increase in Rubisco in treated rice, wheat yield gains averaging 12% and rice gains of 17 to 21% [2]. It is the reason Brix+ is applied so dilute.
02
The response is fast, and runs through a second messenger
Put triacontanol on the shoots of rice seedlings and an adenosine-type second messenger appears in the roots within a minute; in rice and maize, free amino acids, reducing sugars and soluble protein rise within five minutes [2]. Islam and Mohammad (2020, Physiology and Molecular Biology of Plants) add the stress side: under salt, drought and heavy-metal stress, treated plants held higher antioxidant enzyme activity and chlorophyll than controls [3]. More is not better: in one trial the review cites, a tenfold stronger dose gave a weaker response [2].
03
Seaweed extract switches on the plant's own cytokinin production
Wally and colleagues (2013, Journal of Plant Growth Regulation) measured what an Ascophyllum extract did to Arabidopsis hormone genes: cytokinin biosynthesis genes went up and cytokinin breakdown genes went down at 24 and 96 hours, while auxin biosynthesis genes were repressed [7]. They concluded that the hormone levels in the extract are too low to have much effect at recommended rates, and that other components may modulate the plant's own hormone pathways. That is the honest reading of "seven growth promoters": most of the effect probably comes from what the plant then makes for itself.
04
Betaines lift chlorophyll and stand in for the plant's osmoprotectants
Whapham, Blunden and colleagues (1993, Journal of Applied Phycology) showed that tomato plants given an alkaline Ascophyllum extract, on the soil or the leaves, carried more leaf chlorophyll than controls; using a cucumber cotyledon test, they traced the effect at least in part to three betaines [8]. Craigie's 2011 review describes betaines as cytoplasmic osmoticants and notes their proposed role in easing drought, frost and salinity stress [5]. This is the basis for spraying before a frost or a dry spell: you are topping up what a cell uses to hold water when conditions turn.
05
Frost recovery and root biology in the trials
Shukla and colleagues (2019, Frontiers in Plant Science) review the Ascophyllum trials: a lipophilic fraction let Arabidopsis recover from −5.5°C with reduced electrolyte leakage; 1 g/L extract given to 10-day-old alfalfa plants more than doubled the rhizobial bacteria in the rhizosphere twelve hours after inoculation; a root drench improved the growth of strawberry and carrot and raised soil microbial activity [6]. Khan and colleagues (2009) reach similar conclusions on root growth and mycorrhizal colonisation [4]. Hence the drench at planting, paired with a mycorrhizal inoculant.
06
The meta-analysis: sweeter fruit, more of it
Pei and colleagues (2024, PLOS ONE) pooled 73 field studies of seaweed-based products. Yield rose 15.17% on average, fruit crops 20.27%. Soluble sugar rose 17.96%, vitamin C 18.07% and the sugar-to-acid ratio 38.32% against controls. Foliar application gave a slightly larger yield response (13.70%) than root application (11.10%) [9]. These were Chinese field trials, so the exact figures may not carry over to a British garden; the yield gain held in every crop group.
For the alfalfa origin of triacontanol and what it does in a dry feed, see what is alfalfa meal, and is it a good fertiliser?
Scientific references
- Ries, S.K., Wert, V.F., Sweeley, C.C. and Leavitt, R.A. (1977). Triacontanol: a new naturally occurring plant growth regulator. Science, 195(4284), 1339–1341.
- Naeem, M., Khan, M.M.A. and Moinuddin (2012). Triacontanol: a potent plant growth regulator in agriculture. Journal of Plant Interactions, 7(2), 129–142.
- Islam, S. and Mohammad, F. (2020). Triacontanol as a dynamic growth regulator for plants under diverse environmental conditions. Physiology and Molecular Biology of Plants, 26(5), 871–883.
- Khan, W., Rayirath, U.P., Subramanian, S., Jithesh, M.N., Rayorath, P., Hodges, D.M., Critchley, A.T., Craigie, J.S., Norrie, J. and Prithiviraj, B. (2009). Seaweed extracts as biostimulants of plant growth and development. Journal of Plant Growth Regulation, 28(4), 386–399.
- Craigie, J.S. (2011). Seaweed extract stimuli in plant science and agriculture. Journal of Applied Phycology, 23(3), 371–393.
- Shukla, P.S., Mantin, E.G., Adil, M., Bajpai, S., Critchley, A.T. and Prithiviraj, B. (2019). Ascophyllum nodosum-based biostimulants: sustainable applications in agriculture for the stimulation of plant growth, stress tolerance, and disease management. Frontiers in Plant Science, 10, 655.
- Wally, O.S.D., Critchley, A.T., Hiltz, D., Craigie, J.S., Han, X., Zaharia, L.I., Abrams, S.R. and Prithiviraj, B. (2013). Regulation of phytohormone biosynthesis and accumulation in Arabidopsis following treatment with commercial extract from the marine macroalga Ascophyllum nodosum. Journal of Plant Growth Regulation, 32(2), 324–339.
- Whapham, C.A., Blunden, G., Jenkins, T. and Hankins, S.D. (1993). Significance of betaines in the increased chlorophyll content of plants treated with seaweed extract. Journal of Applied Phycology, 5(2), 231–234.
- Pei, B., Zhang, Y., Liu, T., Cao, J., Ji, H., Hu, Z., Wu, X., Wang, F., Lu, Y., Chen, N., Zhou, J., Chen, B. and Zhou, S. (2024). Effects of seaweed fertilizer application on crops' yield and quality in field conditions in China: a meta-analysis. PLOS ONE, 19(7), e0307517.
Figures describe the published literature on seaweed extracts and triacontanol and are not product-specific yield guarantees.
How to Use
How to use Brix+: foliar spray, soil drench and solution feeding rates
Measuring
Specific gravity is 1.0, so 1 ml is 1 g. Half a 5 ml medicine spoon is 2.5 ml, the top of the foliar range for a litre; a 5 litre sprayer takes 10 to 12.5 ml.
Increase frequency, not concentration
Brix+ is designed to be used at low concentration and high frequency. It is preferable to increase the frequency of applications rather than the concentration of the solution. The growth promoters work through signalling pathways that respond to repeated, regular stimulation rather than single high-dose applications. Stick to the dilution rates below and apply regularly through the growing season.
Application rates
Foliar spray — all plants
Shake well before use. Mix 2–2.5 ml of Brix+ per litre of water and apply as a fine spray to both upper and lower leaf surfaces, in early morning or late evening when stomata are open and evaporation is low. Foliar is the quickest route in. Suitable for all plants including lawns, shrubs, roses, tomatoes, vegetables and fruit.
Soil drench — all plants
Mix 5–12.5 ml of Brix+ per litre of water and apply around the root zone with a watering can. The organic acids and phenolics feed rhizosphere microbial activity while the trace minerals and growth promoters are taken up by the roots; a drench gives a longer-lasting, deeper effect than a spray. Use the lower rate (5 ml/L) for regular maintenance and the higher rate (12.5 ml/L) for plants under stress or during peak fruiting demand.
Solution feeding / fertigation — adding Brix+ to a liquid feed
For growers running a two-part liquid feed, add Brix+ to the Part B solution before combining with Part A, or add it directly to the final working solution at 16 ml per 10 litres (1.6 ml/L). The Part B rate assumes roughly 50× dilution into the final reservoir, so do not put 0.4 L per 5 L into the finished tank. Do not pre-mix with concentrated feeds; always dilute into the working volume. The growth promoters and trace minerals supply the biostimulant and micronutrient side that synthetic liquid feeds usually lack.
Stress recovery — before and after frost, drought or heat
Spray at the standard foliar rate immediately before a forecast frost, drought or heat event to prime the betaine and mannitol osmoprotection. If the event has already happened, spray as soon as conditions allow to support recovery: cytokinins delay senescence in damaged tissue, betaines steady the remaining cell membranes and triacontanol restarts photosynthesis.
Growth stage guide
- At planting or transplanting. Apply as a soil drench at 5 ml/L when moving plants into their final position. The auxin signal and trace minerals support root establishment. Dust mycorrhizal fungi powder onto the root ball at the same time for root colonisation.
- Vegetative growth. Begin foliar spraying at 2–2.5 ml/L every 10–14 days. Cytokinins drive cell division and branching, triacontanol lifts photosynthesis, and the plant builds the leaf canopy and root system that will carry the fruit later.
- Pre-flower. Continue foliar applications. The gibberellin signal supports the shift from vegetative to reproductive growth. Increase to fortnightly soil drenches if not already doing so.
- Flowering. Maintain the foliar programme. This is the stage with the most direct bearing on eventual yield: pollen viability, flower retention and fruit set.
- Fruit set and fill. Continue foliar and soil applications through to harvest. Sugar in developing fruit comes from photosynthesis, and triacontanol keeps the photosynthetic rate high; the trace minerals supply the enzyme cofactors that turn photosynthate into sugars, acids and aroma.
Handling notes
Shake or stir well before every use. Do not mix with low-pH solutions; run a jar test to confirm compatibility with other products before tank mixing. Avoid spraying close to harvest on produce prone to staining, as the brown liquid can mark pale-skinned fruit. Do not pre-mix or store in diluted form. Use within 6 months of opening.
Works well combined with…
Brix+ delivers the signal; a base fertiliser delivers the building blocks. Use it alongside Organic All Purpose Fertiliser 4-4-4 during vegetative growth and switch to Organic Bloom Fertiliser 2-8-4 at flowering. Tank-mix with our soluble seaweed extract powder for a double seaweed pass, one for the hormone signal and one for mineral density. Apply our activated biochar condensate (wood vinegar) as a soil drench on alternate weeks for complementary karrikin signalling and microbial stimulation. Add humic acid flakes to soil drenches; the humic acid chelates the trace minerals in Brix+ for root uptake.
Storage
Store sealed in a cool, dry place out of direct sunlight. Crystallisation or sedimentation may occur below 5°C; this is normal and does not affect quality. Warm gently and shake to re-dissolve. Keep away from children and pets.
Questions & Answers
Frequently asked questions about Brix+ liquid seaweed biostimulant
A biostimulant works on the plant's own growth signalling; its nutrient content is small. Brix+ is a seaweed concentrate carrying triacontanol alongside cytokinins, gibberellins, auxins, betaines, mannitol, natural acids and phenolics, plus 74 trace minerals. An ordinary liquid seaweed feed is the extract on its own, sold as a general tonic. The nutrient analysis of Brix+ is low on purpose: 0.26% N, 1.65% K.
Brix (°Bx) is the refractometer reading of dissolved solids in juice or sap, mostly sugars. Squeeze a drop onto the prism of an optical refractometer, close the cover and read the scale against the light. A basic one costs £15 to £25, needs no batteries and only wants a zero check with distilled water now and then. Compare the same variety at the same time of day.
Triacontanol is a 30-carbon fatty alcohol found in the leaf wax of alfalfa and other plants, reported as a growth regulator in 1977. Sprayed on leaves at nanomolar concentrations it raises photosynthetic rate and Rubisco activity, and treated crops in the published trials show higher dry matter and sugar accumulation. It acts within minutes through a second messenger, and a stronger dose does not always give a stronger response, so regular low doses are the method.
Not a primary one, so yes, keep feeding. Brix+ is a biostimulant with low nutrient levels. Use a balanced organic fertiliser as normal and Brix+ as the signal layer on top: All Purpose 4-4-4 through veg, Bloom 2-8-4 from flowering, Brix+ sprayed throughout.
Foliar at 2 to 2.5 ml per litre every 10 to 14 days, or as required, and a soil drench at 5 to 12.5 ml per litre every 4 weeks. If you are tempted to do more, raise the frequency rather than the strength. Spray in early morning or late evening so the leaf stays wet long enough to absorb it.
Yes. Foliar spray at 2 to 2.5 ml per litre every 10 to 14 days, in the morning onto dewy grass. Most useful as a recovery spray after summer heat or ahead of a dry spell. It will not replace a lawn feed.
Usually, but jar test first. Mix a small amount with the other product at the intended dilution and watch for precipitation, clumping or a colour change. Do not mix with strongly acidic (low-pH) solutions. Brix+ is compatible with most organic liquid feeds and seaweed extracts, and goes into humic acid soil drenches. Make it fresh each time and do not store the diluted mix.
It is a brown liquid and can leave a visible residue on pale-skinned fruit or light foliage if applied close to harvest. On green leaves it is not noticeable and rain washes it off. For show fruit or produce sold unwashed, stop spraying a few days before picking.
Brix+ is a plant-based seaweed extract with trace nutrient levels, used at 2 to 2.5 ml per litre. It is a biostimulant, not a plant protection product. As with any concentrate, store it sealed and out of reach, and let sprayed foliage dry before children or pets go back onto the lawn.
Sealed, cool, dry and out of direct sunlight. Use within 6 months of opening. Below 5°C it may crystallise or throw a sediment; that is normal, and warming it gently and shaking brings it back. Do not store it diluted.
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