Welcome to the intstruction page for the Danú, the live microbial innoculant that is produced by Probio Carbon in association with Saruyama Bonsai. The basic ideas and principles of Danú are covered in the video below, featuring an interview with Dr. Karen O’Hanlon who developed the product specifically for bonsai cultivation. It is based on three strains of beneficial bacterial that were identified from a fertile Irish meadow and have proven to help improve the health of bonsai, specifically induced disease resistance, improved uptake of nutrients and increased plant signalling capabilities.

Danú is most effective when used at repotting time and the growing medium is fresh and there is no establish soil biome. Application of Danú to the roots and fresh soil will be the most efficient way of establishing a large biome quickly which is essential for the recovery of repotted trees, especially those that have been in poor health or have transitioned from yamadori collection to a bonsai container for the first time.

Using Danú in the spring even on trees that have not been repotted is still recommended. The other time for effective use is towards late summer, early autumn (August and September in the UK). This appears to boost the development of adventitious buds as well as being an important time for root development.

What does Danú do? What doesn't it do?

It introduces three strains of bacteria to the rhizome (the area around the roots), that work in harmony with the tree to promote healthy growth. Healthy growth is resistance to disease and the ability to withstand stress. Danú is specifically designed NOT to promote elongated growth. Using Danú will not cause vigorous growth on your trees

What dilution rate should I use?

Ideally one 200 mL bottle should be diluted into between 5 and 10 L of water.

For the dried product, use enough to give a light and even coverage across the soil surface. Between 2 and 10 teaspoons depending on the surface area of soil.

What water do I use to mix?

Ideally rain water or anything else that is chlorine free. Tap water is fine if left to remove any residual chlorine. Small trace amounts will not kill the entire population of bacteria in the Danú, but it can reduce numbers and lower the efficiency of application pH should ideally be between 6 and 7.5

How do I store Danú and how long does it last?

Undiluted liquid Danú must be kept in a refrigerator and will keep for up to four months, however one strain of bacteria is unstable in liquid form and the concentration will deteriorate after one month. It is most effective if used within one month. Once diluted in water, it should be used immediately.

The dried form of Danú is more stable and will keep for up to a year once it has been opened, as long as it is kept in a cool, dark and dry environment, ideally refrigerated, but not essential.

When do I apply Danú? Does it need any special treatment afterwards?

It is best applied during the spring repotting season, ideally when soil temperature is above 10°C. Once applied to the root zone, the bacteria will attach themselves to the roots and stick there. You can water as normal afterwards and not worry about periods of heavy rain.

How do I apply it?

Dunking trees in a solution of diluted liquif Danú is the most effective way of inoculating the rhizosphere with the bacteria. Alternatively it can be watered on using a watering can or sprayer. The idea is to get the bacteria onto the roots, not to pour so much on that it drains out of the bottom of the pot is wasted. It is only effective when it is in contact with the roots so only pour it into the pot where roots are present.

Sprinkle the dried product evenly and lightly across the soil surface, as shown in the video below. After application, water lightly to start the rehydration process. Alternatively when repotting, you can sprinkle some underneath and on the root ball when placing it into the pot with fresh soil. It will then be in immediate contact with the roots.

How does the dried product differ from the liquid?

The strains and the count of bacteria will be the same in both products, but the mode of application is different. In the dried product, biochar and peat are used as a carrier medium for dried spores are reactivated when rehydrated and can then colonise the roots. It is a fine mix and is sprinkled on the surface in the same way as an organic fertiliser would be. There is no impact on the ability for water and oxygen to penetrate into the root ball from the use of the dried Danú.

How do I purchase it and can it be shipped around the world?

It can bought direct from the producerProbio Carbon hereDue to the nature of the product it can only be shipped in the UK and EU currently, although the dried product will soon be available in the US and further afield. Please contact Probio Carbon for more details. It is also produced to order and in season, so there may be a short wait to receive it.