Magnolia

Care & Maintenance

Once established, Southern Magnolia in Southern California needs deep watering every 7 to 10 days in summer rather than frequent shallow irrigation, which encourages the surface roots to spread toward hardscape. Pacific Northwest magnolias typically need little supplemental water after the first two years. Both species prefer slightly acidic, well-draining soil and at least half a day of direct sun. Skip high-nitrogen fertilizers, they push leafy growth at the expense of flowers.

Common Issues & Threats

• Magnolia scale (Neolecanium cornuparvum): This is the largest soft scale insect in North America and it specifically targets magnolias. It looks like brown or tan bumps clustered on the branches, and most homeowners mistake it for normal bark texture until the infestation is severe enough to produce sticky honeydew and black sooty mold on everything below.
• Leaf spot diseases (Phyllosticta magnoliae, Pestalotiopsis species): Dark spots with yellow halos appear on leaves, and in the Pacific Northwest wet winters make this a recurring problem. On established trees it is mostly cosmetic, but on young trees repeated defoliation stunts growth and makes recovery slow.
• Surface root heaving: Magnolia roots are wide-spreading and shallow by nature, and they will lift sidewalk slabs, crack driveway edges, and compete aggressively with lawn and irrigation systems. No root barrier installed after planting will stop this long-term. If you are planting near hardscape, give the tree at least 15 feet of clearance or choose a dwarf cultivar like Little Gem.

Pruning Guide

Here is what most people get wrong: magnolias are routinely pruned in winter when the tree looks dormant, but that is actually the worst time. Magnolias bleed heavily from dormant-season cuts and are slow to compartmentalize wounds, which invites fungal decay into the heartwood. Prune in late spring after flowering ends, using clean cuts at the branch collar and avoiding any cut larger than three inches in diameter if you can help it. Remove dead, crossing, or structurally weak branches and leave the rest alone.

Did You Know?

Magnolias are among the oldest flowering plants on earth, evolving before bees existed, which is why their flowers are pollinated by beetles and built tough enough to survive that kind of rough handling. The bright red and orange seeds inside the dried seed cones are toxic to dogs and cats, so if you have pets that investigate fallen debris, that is worth knowing before you plant one.

Where Magnolia Is Found

Magnolia is common in 733 of the US communities we cover, across 2 climate regions.

... and 721 more cities