Hardwood care: let it weather or keep the colour?

A planter, bench or letterbox in solid hardwood lasts for decades outdoors without you having to do anything. Still, we often get the same questions: do I need to treat the wood, why does it turn grey and are those small cracks normal? This article covers it all.

Does hardwood need maintenance?

No. The hardwood we use belongs to the highest durability classes (class 1 or 2 according to the European standard EN 350). This standard measures how long untreated wood resists fungi and rot, from class 1 (very durable) to 5 (not durable). For comparison: oak is class 2, pine and spruce class 4.

The durability is in the wood itself, so no chemical treatment is needed. Maintenance is only a choice about colour.

Why does hardwood turn grey?

Under UV light, all hardwood weathers to a silver grey patina within 6 to 12 months. This is purely aesthetic: strength and durability stay the same. Many people deliberately choose this natural grey look.

Three choices for your hardwood

Let it weather: do nothing, just brush it down with water now and then. You get a silver grey patina with zero maintenance.
Keep the colour: oil the wood 1 to 2 times a year with a UV-protective hardwood oil, lightly pigmented if you like. The warm colour stays and the wood gets dirty less quickly.
Restore the colour: if the wood is already grey, use a wood reviver or sand it lightly, then oil it. This brings back almost the original colour.

How to oil hardwood

Work on dry, clean wood, preferably on a dry day without strong sun.
Apply the oil thinly, following the grain.
Wipe off the excess with a cloth after about 15 minutes.
Do not use varnish or lacquer: it forms a film that peels outdoors.

What is normal for solid wood?

Solid wood is a natural product. These characteristics are normal and not defects:

Colour differences between boards and within a single board.
Fine hairline cracks as the wood moves with dry and wet weather. They do not affect strength.
Tannin run-off during the first weeks of rain. This can leave red or brown stains on tiles or concrete. Avoid a light surface during the first weeks, or put something underneath.
Black stains appear on contact with ordinary iron, so avoid rusting metal objects on or against the wood.
Small wormholes: traces of insects in the living tree. They are not active and do not affect strength. We fill them wherever possible.

Why our hardwood products last so long

Class 1 hardwood lasts 25 years or more even in contact with the ground. Still, we keep the wood out of the wet: our hardwood products stand on legs, feet or a mounting plate. This stops water being drawn into the end grain, the weakest point of any board. The wood dries quickly after rain, which limits cracking and prevents damp stains on the surface below.

Wondering which product suits your garden? Browse our wooden planters and wooden letterboxes, or read more about hardwood as a material. Need something made to measure? Submit your request here.