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Yates FlowTrace

Yates FlowTrace

Yates FlowTrace is a free flowing, finely ground trace element mixture, designed for incorporaton into potting media. FlowTrace is a one-shot method of providing all trace elements to typical Australian potting media. The balance between the various trace elements in FlowTrace is based on extensive research by Australian plant nutrition authority Kevin Handreck. Guaranteed Analysis:

Iron (Fe) 24%
Copper (Cu) 0.75%
Manganese (Mn) 0.5%
Zinc (Zn) 0.2%
Molybdenum (Mo) 0.04%
Boron (B) 0.033%


  • Yates FlowTrace is a complete trace element mixture for potting media
  • FlowTrace has been formulated specifically for Australian potting media, whose main components are pine bark and woody composts
  • Yates FlowTrace is a one-shot method of providing all trace elements to typical Australian potting media. No longer is it necessary to separately add iron sulphate and another trace element mixture
  • The FlowTrace formulation is based on extensive research by Australian plant nutrition authority Kevin Handreck
  • Yates FlowTrace has a much higher iron content than other trace element mixtures, because iron is the trace element that is most commonly lacking in wood waste-based media
  • After iron, copper is the trace element needed in highest amounts in Australian potting media. Its concentration in FlowTrace is therefore higher than in other mixtures
  • The manganese content is low because this trace element is usually already present in adequate or near-adequate amounts in pine bark and other organic components
  • At the recommended addition rate, zinc and boron will be supplied in adequate amounts. However, halving or doubling the rate of use of FlowTrace will not cause deficiency or toxicity
  • Yates FlowTrace contains zeolite, so it will never cake or set solid
  • Yates FlowTrace is finely ground and flows easily, so it quickly spreads throughout potting medium into which it is incorporated
  • Incorporation of FlowTrace at recommended rates will ensure that the plant-available trace element contents of the vast majority of Australian potting media will be within the optimum ranges, as listed in the Australian Standard for Potting Mixes

How It Works

As the trace element chemicals dissolve in water in the potting medium, the iron, copper, zinc and manganese react with phenols and humus to produce chelated forms of these trace elements. These naturally chelated trace elements are held firmly on and within the particles of bark and wood within the medium. Because they are spread throughout the medium, they are readily accessible by plant roots throughout the medium.

Directions for use

Yates FlowTrace is only recommended for addition to a potting medium or its components before potting. It may be added to bark and other wood wastes before these are composted, or to the mixture of components as they are being blended into a potting medium.

  • When Yates FlowTrace is to be the sole source of added trace elements, incorporate it at a rate of 1 kg/m3
  • When one of the components has already had some iron sulphate added to it (for example before composting), the rate of incorporation of FlowTrace can be reduced, but to no less than 0.5 kg/m3
  • It could be necessary to increase the rate of addition to no more than 1.5 kg/m3 if a potting medium contains a high proportion of fine humified organic matter

Additional Information

The iron, copper and zinc will remain in plant-available form for many years, provided the pH of the medium remains within the range 5 to 6.4. An increase above pH 6.4 may reduce supply of these trace elements to some plants. There is no need to repeatedly add further amounts of these trace elements for most plants (zinc for citrus is an exception).

The added molybdenum will also remain available for many years.

Under non-leaching conditions, the added manganese and boron will also remain available for several years, but when pots are constantly leached through excessive applications of irrigation water, both of these trace elements are slowly leached from potting media. However, even in the “worst-case” situation of heavy leaching, the amounts of manganese and boron added by the recommended FlowTrace addition will last for one year.


Pack size: 1T Bulk Bag