Sourwood Oxydendrum arboreum

Water

The Sourwood tree (Oxydendrum arboreum) prefers consistent moisture but requires well-drained soil. During its growing season in spring and summer, water the tree once a week with about 1 to 1.5 gallons of water, unless there is sufficient rainfall. Decrease the frequency to every two to three weeks during the fall before the tree becomes dormant in winter. If the weather is particularly dry, you might need to water the tree during the winter months. Always check the soil moisture at about 2 inches depth; if the soil feels dry, it's time to water.

Light

The Sourwood tree thrives in full sun to partial shade conditions. Ideally, it should receive at least four to six hours of direct sunlight per day. The best spot for planting a Sourwood tree is in a location where it will receive morning sunlight and some afternoon shade, especially in hotter climates, to prevent stress from excessive heat.

Temperature

The Sourwood tree is able to withstand a range of temperatures and climates but prefers moderate conditions. It can survive in temperatures as low as -20°F and as high as 90°F. The ideal growing temperatures for this tree range from 60°F to 80°F. Oxydendrum arboreum is a hardy tree once established but should be protected from extreme cold when young.

Pruning

The Sourwood tree requires minimal pruning, mostly to maintain its shape and remove any damaged or diseased branches. Prune the tree during its dormancy in late winter or early spring before the new growth starts. Remove any crossing or rubbing branches to promote healthy growth and good air circulation. Occasional thinning may be necessary to maintain the tree's structural integrity.

Cleaning

As needed

Soil

The Sourwood tree prefers acidic soil with a pH between 5.0 and 6.5. A good soil mix should be well-draining and rich in organic matter. Incorporate peat moss, compost, and a pine bark mix to create an ideal substrate for this tree's roots.

Repotting

Sourwood trees are typically not repotted as they are trees meant to be planted outdoors. Once established, they do not require repotting; if transplanted, it should be done during dormancy in late fall or winter.

Humidity & Misting

Sourwood trees thrive in an environment with moderate humidity. They are adaptable to outdoor conditions in their native range and do not require specific humidity levels when planted in the landscape.

Suitable locations

• Indoor

  Sourwood is not suitable for indoor growing due to its size.

• Outdoor

  Plant in acidic soil, full sun to partial shade, and water regularly.

• Hardiness zone

  5-9 USDA

Life cycle

Oxydendrum arboreum, commonly known as the sourwood or sorrel tree, begins its life cycle with seed germination, which is facilitated by a combination of warm temperatures and moist soil conditions. Upon germination, the seedling emerges and begins to grow roots and shoots, developing into a young sapling. As the sapling matures, it undergoes a period of vegetative growth where it establishes a robust root system and a sturdy trunk, simultaneously growing in height and girth. During this stage, the sourwood develops its characteristic elongated leaves that turn brilliant shades of red and purple in the fall. Upon reaching maturity, which can take several years, the sourwood produces clusters of fragrant, white flowers during the summer, which are highly attractive to pollinators like bees, and eventually give way to seed capsules. The tree continues to cycle through seasonal growth and reproduction, with mature trees living up to 100-200 years, creating new generations through seed dispersal, as well as contributing to the ecosystem as a valuable source of nectar and through its falling leaves that enrich the forest floor.

Propogation

• Propogation time

  Spring-Early Summer

• Propogation: The most popular method of propagating the Sourwood (Oxydendrum arboreum) is through seed. Seeds should ideally be sown in fall directly after collection to take advantage of the cold winter months that help break the seeds’ dormancy through a process called stratification. However, if immediate sowing isn’t possible, seeds can be stored in a cool, dry place and then stratified artificially by mixing them with moist sand and placing them in a refrigerator, usually set at about 40 degrees Fahrenheit (4 degrees Celsius), for about 60 to 90 days before sowing in the spring. The stratified seeds are then sown in well-drained soil in a sunny location, lightly covered with soil, and kept consistently moist until germination, which can take several weeks. Because Sourwood is known for its slow growth and difficulty in transplantation, seeds are often preferred to establish new plants in the location where they are intended to grow to maturity.