How to Care for Tanalised Timber

mySmartGarden's Guide to Caring for Tanalised Timber

Over time pressure treated timber can crack and split from water exposure and this will allow fungi to get into the cracks and create wood rot. As water is an inevitable part of planting and growing rituals, we’ve compiled a maintenance guide to ensure optimum use of our planters. These tips will also help prevent some naturally occurring problems.

Naturally Occurring Problems:

  • Shrinking & Swelling - The continuous absorption and loss of water can cause natural defects in tanalised wood like twisting, warping and splitting to occur. A water repellent sealant or semi-transparent stain made for pressure treated timber applied annually (or biannually) is key to reducing this water movement.


  • Mildew Growth - This can occur when wood is frequently exposed to humid conditions. To keep your timber attractive and bright, wash with a cleaner containing mildewcide. 


  • Ultraviolet Protection - Exposure to UV rays can cause discolouration of timber over time. If you would like to maintain the natural colour of your planter, we suggest to clean annually and apply a water repellent finish with an ultraviolet stabiliser. Although this will not wholly prevent discolouration it will slow the process. 

Maintenance on your wooden planter is important to ensure it will look its best for years to come. Depending on the location of your planters in regards to exposure to direct sunlight, moisture and foliage coverage, you may only have to clean and re-coat every two years.

My SmartGarden's simple steps to help maintain pressure treated timber:

  1. Wash your planter with a cleaner that contains mildewcide. If your planter is new, this step is truly preventative. 
  2. Protect your planter with a water repellent stain.
  3. To keep pressure treated timber in tip top condition we recommend maintenance every 12 - 24 months. 

 If you opt to clean your planter every two years you may want to use a power washer.