Sweet Bay magnolia leaves are yellow


Hi. My sweet bay magnolia’s leaves are very yellow… with faint green in the centre (see photo). I’m sure it’s lacking something in the soil. Would you be able to tell me what to ad? It’s growing in full sun (11 on) in clay soil that has been amended with chunky peat to make it more acidic. It has flowered every year except this year. Thanks. – A


The appearance of those leaves is typical of chlorosis, which can be caused by a variety of factors, but most often, nutritional deficiencies.

Here is how the University of Minnesota explains it. Discoloured leaves

The same issue applies to the flowering problem. Both a lack and an excess of nutrients can cause a magnolia not to bloom.

We recommend you get the soil tested, in order to know what is missing and what can be done about it.  We recommend the City of Toronto’s Guide for Soil Testing in Urban Gardens, which outlines a step-by-step process you can follow. Click here to read or print it. The University of Guelph’s Agriculture and Food Laboratory information can be found here.