Do Magnolias Need Full Sun, Partial Shade, or Full Shade?
Trying to figure out how much sun your magnolia tree needs before putting it in the ground? These popular trees are fairly adaptable, but will thrive in certain growing conditions. In this article, gardening expert Melissa Strauss examines if your magnolia needs full sun, partial shade, or a fully shaded location to grow well.
Should you plant magnolia in sun or shade? Magnolia trees are a diverse and beautiful family of plants. There are many sizes, flower colors, and blooming habits to choose from. Some magnolias are evergreen and love heat and sun. Others are deciduous and can be a bit more fragile than their evergreen cousins.
So how much sun do magnolias need, and when is the best time to get those sunlight hours? The answer is multifaceted and hinges mainly on the species of magnolia, its bloom time, and the climate in which it is planted.
Let’s discuss the best place to plant a magnolia, considering its climate, species, and blooming habit.
The Short Answer
Magnolia trees produce the greatest number of flowers when they are planted in full light. Full sun means a minimum of 4-6 hours of direct, unfiltered sunlight.
Some varieties are more shade tolerant, and some early blooming varieties need protection from southern exposure. But, in general, magnolias like a lot of sunlight. Morning sun is best, with some shelter from the heat of the afternoon sun.
The Long Answer
The sun exposure that a magnolia needs differ based on the species, its flowering habits, and the climate zone in which it is planted. To answer the question of how much and when a magnolia needs sunlight, we need to determine the species, blooming habit, and climate in which the tree is being planted.
Deciduous magnolias are more cold tolerant but bloom earlier, which puts them at risk of cold damage, especially for early flowering species. Evergreen species are quite drought tolerant and produce the most flowers when given lots of sun, but the time of day they receive that sun is important.
Early Blooming Deciduous
The earliest blooming of the deciduous magnolias is M. stellata, or the Star Magnolia. Stellata blooms in late January in most climates. It is a smaller variety, and has a shrubby habit, growing to only about 15’ tall and wide. Because of its early blooming time, it is important to consider the climate, and protection of the blooms.
Stellata is hardy in zones 5-9 but has different needs depending on which zone you are planting in.
This early blooming group also includes the beautiful M. denudata, a white variety of deciduous magnolia that blooms in late winter. Both species are noted for their extreme beauty, but they are a bit more high maintenance in terms of where they need to be planted.
When growing in warmer climates (zones 8-9), Stellata will want partial sun and some protection in the afternoon. If planted in direct sun, make sure those sunny hours are in the early part of the day.
Too much hot sun will scorch leaves in the summer and diminish the plant’s drought tolerance. During the hottest months, particularly in drought, these species will need to be watered more than in cooler climates.
In colder climates, striking a balance is a bit more complicated with this early bloomer. These species will bloom best with full sun exposure. However, southern exposure will cause the tree to flower earlier than it should, making it more vulnerable to frost.
This variety can withstand temperatures of 30°, even when in bloom. It is a cold-tolerant variety, but the later it blooms, the better the chance of all those gorgeous flowers living their best life.
While these magnolias will flower best with full sunlight, they may need some protection from freezing winds. The cold temperatures may not extinguish the blooms, but freezing winds can do much damage. The ideal spot for these magnolias is east or west sunlight exposure, with a bit of a wind buffer, away from southern exposure.
Hybrid and Late Blooming Deciduous
The two species of deciduous magnolias that are later spring bloomers (February-April) are M. kobus and M. Liliiflora. These species are more cold tolerant, with some varieties able to survive the winters of zone 4.
The Japanese Magnolia (magnolia x soulangeana) and the Loebner Magnolia (magnolia x loebneri) are hybrid varieties bred specifically to have later bloom times.
The Japanese magnolia variety, also known as Magnolia soulangeana, is a cross between M. denudata and M. liliiflora. The Loebner Magnolia is a cross between M. stellata and M. kobus.
The reason for hybridization was to attain the beauty of the earlier blooming varieties while improving upon the cold hardiness. Hybrids have extended bloom time by about 4-6 weeks. This later bloom time means there is less chance of damage to the blooms from a late frost. All of these varieties are hardy, more or less, in zones 4-9.
In warmer climates, these magnolias do well in full sun, but remember that too much afternoon sun during a drought can pose the issue of leaf scorch and may dry the tree out.
This is less of an issue in cooler climates than in hot climates, but still important. If planted in direct sun in warmer climates, these varieties will likely need some extra watering in the hottest months.
The same placement rules apply to these species as with the earlier bloomers. Although they are later blooming, they will bloom earlier in southern exposure. It is best to avoid southern plantings with these varieties.
Their later blooming habit makes them less susceptible to freezing weather and cold wind, so there is less need to shelter them from these factors. But in zone 4, most will need at least some protection from the wind.
Summer Blooming Deciduous
M. macrophylla and M. sieboldii are species of deciduous magnolia trees that bloom during the summer months. This unique characteristic eliminates the issue of frozen flowers entirely.
These species are best suited for zones 6-9, although zone 5 is not out of the ordinary. These trees do best in part sun, with full sun in the morning. Afternoon shade is ideal in hotter climates because too much heat can damage flowers just as freezing weather can.
Like other deciduous varieties, full sun in the morning is ideal, with filter afternoon sun. If this is not possible, extra water will do the trick and keep those summer flowers looking fresh.
In the cooler climate zones, these trees tolerate and perform best in full sun if the soil is kept moist. Some protection from strong winds will help preserve the flowers of these species.
M. grandiflora and M. virginiana are the two evergreen species of magnolia. Virginiana tends to be deciduous above zone 7, where it would be grouped with the summer blooming deciduous species. Still, for planting purposes, we will group it with its closest cousin, grandiflora, or Southern Magnolia.
Both of these trees like a lot of sun. Both species need a minimum of 4 hours per day of unfiltered direct sunlight to see them reach their full potential.
The Southern Magnolia (grandiflora) is very drought and heat tolerant once mature. In its early years, if you plant in direct sunlight, be sure to keep the soil moist, or you will risk leaf scorch.
A bit of afternoon shade is ideal for these trees, although they can survive in truly full sun. The hot afternoon sun will put the flowers at risk of falling before their time, so ideally, a bit of shelter from the heat in the afternoon is best.
M. virginiana will do best with afternoon shade or filtered sun during the hottest hours. Its leaves are slightly less tough than the grandiflora’s, so they are more susceptible to leaf scorch or yellowing in very hot and dry conditions. 4 hours of unfiltered, full sun in the morning is perfect for this species. This species will likely need extra watering in a drought if planted in full sun.
In cooler climates, both species of magnolia will perform best and bloom the most prolifically in full sun. These trees do not do well north of zone 6, so very cold winters won’t serve.
However, they do just fine in zones 6-8, which frequently see freezing temperatures in the winter. As I mentioned, Virginiana will perform as a summer-blooming deciduous tree in zones 6-7. Protection from cold winds in those cooler climates will help your magnolia keep as many leaves as possible.
Deciduous magnolias need balance, in colder climates, between sunlight and protection from freezing winds. While they need at least 4 hours of direct sun daily to produce those beautiful flowers, they also need some shelter to protect their blooms from harsh wind and weather.
In warmer climates, the same sun requirement stands, but the best place to plant is where your magnolia will get those full sun hours early in the day and have some respite from the afternoon heat.
Too much heat can dry out an evergreen magnolia’s leaves and flowers during the hot summer months. Ideally, full sun early in the day and filtered sun in the afternoon is best. A little extra water during the hottest months will give these trees the best chance of blooming and retaining their foliage.