Magnolia Question

[Keno763]

I am considering planting a Magnolia tree but I've heard that nothing will grow under them, similar to a Black Walnut. I tried doing a search on this but all I get are references to evergreen Southern Magnolias. I'm in Minnesota and only the deciduous ones will survive our winters. I'm only wanting grass to grow there, although I could could have a mulch ring around the base. Can anyone tell me if the allelopathic problem applies to all magnolias or is that just with the evergreen ones?

 

[Meadowlark]

The Southern Magnolias are definitely allelopathic...more so than even Black Walnuts. Nothing grows underneath mine all the way out to and beyond the drip line...see attached.

I tried to research deciduous magnolias but also could not find anything specific on them re allelopathic. Your best bet might be to drive around your local area and look for some specimens. I suspect you will find them all allelopathic.

 

[Oliver Buckle]

The garden we visited the other day has a lot of magnolias, things definitely grew under some of them, and their brochure talked about the spring flowering underplanted with bulbs. Have a look here:-

Magnolia watch at Great Comp Garden - Great Comp Garden

Magnolia trees are starting to bloom in one of Kent's best spring gardens.

www.greatcompgarden.co.uk

 

[Keno763]

The garden we visited the other day has a lot of magnolias, things definitely grew under some of them, and their brochure talked about the spring flowering underplanted with bulbs. Have a look here:-

Magnolia watch at Great Comp Garden - Great Comp Garden

Magnolia trees are starting to bloom in one of Kent's best spring gardens.

www.greatcompgarden.co.uk

Thank you for the link! I believe most of the trees pictured are deciduous and yes there was plant growth underneath. At this point I'm thinking that the allelopathic qualities may be stronger in the evergreens and it's also possible that the year-round leaf drop makes it stronger since it's constant. With deciduous ones the leaves can be cleaned up all at once.

 

[Keno763]

The Southern Magnolias are definitely allelopathic...more so than even Black Walnuts. Nothing grows underneath mine all the way out to and beyond the drip line...see attached.

I tried to research deciduous magnolias but also could not find anything specific on them re allelopathic. Your best bet might be to drive around your local area and look for some specimens. I suspect you will find them all allelopathic.

View attachment 99787

This looks like the tree in my mother's yard in California. This is what I'm hoping to avoid.

 

[cpp gardener]

There isn’t an allelopathy issue with Magnolias. There is a root competition and shade from big plastic leaves though. But that’s only Southern Magnolias. The deciduous ones just hate a lot of disturbance around their roots. A mulch ring is probably best under them.

 

[Meadowlark]

There isn’t an allelopathy issue with Magnolias.

Wrong! Completely wrong.

"Magnolia trees are allelopathic, meaning they exert compounds, like costunolide and parthenolide, that are harmful to nearby plants."

What Flowers Grow Under Magnolia? (weekand.com)



"Magnolias are allelopathic. This means that they have a chemical in them that will release into the soil that prevents other plants from growing well or even not at all ."

Do Magnolia Leaves Make Good Mulch? - The Backyard Bloom

Many, many other references available and all say "Yes" to allelopathic in Magnolias.

Did you even look at the picture I posted of my Magnolia?

 

[cpp gardener]

Seen many like that and even ones with no leaf mulch. Figured it was the competition and shade. Mea culpa.