What are the expansion/contraction rates of eucalyptus in outdoor flower boxes?

Eucalyptus wood is a popular choice for outdoor flower boxes due to its durability and aesthetic appeal. However, like all natural materials, it undergoes expansion and contraction due to environmental factors such as moisture and temperature changes.

The expansion and contraction rates of eucalyptus depend on its grain orientation and moisture content. Typically, tangential expansion (along the growth rings) ranges between 6-12%, while radial expansion (across the rings) is around 3-6%. In outdoor settings, prolonged exposure to rain or humidity can cause significant swelling, while dry conditions lead to shrinkage.

To minimize warping or cracking in flower boxes, proper sealing with a water-resistant finish is essential. Additionally, allowing small gaps between boards during construction accommodates natural movement. Regular maintenance, such as reapplying sealant, helps preserve the wood’s integrity over time.

Understanding these rates ensures better design and longevity for eucalyptus flower boxes in gardens or patios.