Mycorrhiza: What is it?

What does Mycorhizza and is it really necessary?

Mycorhizza are fungal spores (like mushrooms) which are everywhere in good natural flora. They form a network between plants creating an immens living organism. Through this network nutrients and moisture is shared so that every member of the network can benefit even when they aren't in ideal soil.

How does it affect roses in our garden? Especially in alkaline soils and soils low in nutrients such as phosphate the roots of roses send out an SOS to mycorrhiza fungi. The Mycorhizza comes to the rescue and penetrates the roots of the rose establishing a highway of nutrients, especially phosphate, to help the rose. In dry summers such as this year the mycorrhiza will keep your roses more resistant to drought because the network provides the moisture. Once the roots of our roses are infected by the mycorrhiza they will triple in size and protect the rose better against diseases and nutrient deficiency. This my friends is how Mycorhizza works.

Mycorhizza thrives in soils with lots of organic material also called humus (no not Hummus lol). A thick layer of organic material each year will ensure the working of mycorrhiza.

However! Mycorrhiza has one arch enemy: Chemicals and chemical or artificial fertilizer. It causes the mycorrhiza to retreat and leave that soil being affected by the chemicals. That's why when you treat your roses with mycorrhiza you can never ever spray with chemicals and use chemical fertilizers. You can only use organic fungicides such as Neem or Milk and only organic fertilizers. So in essence: When you treat your rose roots with mycorrhiza you immediately have to start with organic gardening.

Isabelle Olikier Luyten has written a book in French about her little piece of paradise, her 600 square meter garden in which she combines roses from Warren Millington and Austin with perennials. Isabelle treats the roots first with mycorrhiza and she gives each rose 2 kg of manure/compost each year so her soil is one thick layer of organic humus. Isabelle doesn't fertilize her roses! She says the mycorrhiza in combination with the thick organic layer provide enough nutrients for all her roses and perennials. That's the power of the mycorrhiza network!

But Dirk, I have my soil analysed and it isn't alkaline, it's neutral and it has enough nutrients especially phosphate... do I need the Mycorhizza? That's up to you. If you don't intend to grow your roses organically without chemicals mycorrhiza won't help your roses because the mycorrhiza will die anyway.

But if you are intending to grow them organically with the thick organic layer and no chemicals you can skip the mycorrhiza treatment because they will appear naturally to help your roses.

I hope I made it a bit more clear for you guys.