Q.Fertilizing magnolia trees
I live on the South Carolina coast in zone 8. I have a large (50-60 ft) magnolia on the property. It is dense with large shiny leaves but produces very few flowers. Is that because older, more mature trees don’t flower well or is there some kind of fertilizer/mineral I can use to promote flowering?
How long has this flowering issue been happening? The buds of magnolias are very sensitive to extreme weather - did you have a frost that could have damaged your magnolia's buds?
Thrips can also be to blame as they like to attack magnolia flower buds. For more information on thrips, please visit the following link:
https://www.gardeningknowhow.com/plant-problems/pests/insects/controlling-thrips.htm
Magnolias also like slightly acidic soils. I would get a soil test from your local extension office and see where things stand. In terms of fertilizer, my research indicated that phosphorus and micronutrients stimulate flowering.
Here is a link that will help you find your local extension office:
https://www.gardeningknowhow.com/extension-search/