First up, if your wooden garden furniture is made from a hardwood, which the majority is, it has a head start in it’s life and longevity. Outdoor furniture hardwoods include eucalyptus, teak, oak, iroko, acacia and sapele. These are all naturally durable and very well suited to staying outside year-round. They can withstand both the dry heat of the summer and the cold and wet of British winters due to the fact they contain their own protective oils. Teak is the Rolls Royce of outdoor woods. We use eucalyptus wood for our parasols. Not only is it naturally resistant to decay and insects, it is inherently dense and strong, and as eucalyptus trees are fast-growing compared to other hardwoods, it is a more eco-friendly choice.
When to clean wooden garden furniture
Spring time! Yes it can be wise to give your wooden garden furniture a little tlc before you wrap it up for winter, however even with the best care and storage, you might rediscover your furniture on the first sunny day of March, and find it has grown fungus or mildew. So save your big effort for a breezy spring day.
If using any oils or varnishes, the temperature mustn’t be too hot or too cold, as the products won’t cure correctly, so check the instruction labels. You should be fine if the temperature is between 10 and 20 degrees celsius.
How to clean hardwood garden furniture
The first step is a simple wash with hot soapy water and a brush. Give an extra scrub to any areas with green moss or lichen growth, and try to rub in the direction of the grain to get into the grooves of the wood.
Now, depending on your personal taste, you could stop there. The silver, aged look of older hardwood is part of its character. If you’d prefer to try and bring your furniture slightly closer to it’s appearance when new, continue.
I have been known to blast the pressure washer at my teak garden bench for it’s spring clean. It seems to take it fine, and the pressured water alone seems to bring back the golden colour of the wood year after year. This approach is definitely not recommended for parasols however. The mast poles of parasols are made from sections of hardwood essentially glued together. A process called lamination, which increases the strength of the pole and ensures no warping. The jet blast could weaken the lamination layers, so keep the pressure washer at bay.
If your wooden outdoor furniture is very dirty and needs a more thorough clean than soapy water, you can either give it a light sand, or use a hardwood cleaning product. Osmo make a Wood Reviver Power Gel which penetrates wood and removes the grey patina.
NB, if your furniture has been stained with a coloured wood stain, sanding or using an abrasive chemical cleaner will remove some of the colour, and it may need re-staining, so go easy if you don't want an extra job.
Maintaining and treating hardwood garden furniture
Left untreated, outdoor hardwoods will weather naturally and develop an attractive silvery-grey finish. In fact good quality hardwoods can last for many years with no treatment at all, thanks to their natural oils. If you like this look, you’re in luck. Just lay back and enjoy your furniture. Other than an annual clean, your work here is done.
If you’d rather keep your furniture looking younger and newer, there are a dizzying number of products on the market. Oil vs varnish vs wax vs protector vs stain. Let us try and break them down, in the context of hardwood outdoor furniture.
Wood restorer or reviver
These are cleaners rather than protectors. They can be used to remove ingrained dirt and restore the natural colour of wood. If you like to bring back the honey colour to your outdoor wood each year, use one of these products if a good old soapy scrub hasn't done the trick.
Teak Protector or Wood Preserver
These products are like sunscreen for hardwood furniture, and help to block the sun’s rays and it’s greying effects. Using a water-based product is advisable for outdoor seating, to remove worries of oil residues marking clothes.
Teak Sealer
A water-proofing product, that also protects against food and drink stains. Save this for the yachts, your furniture doesn’t need this.
Teak Oil
Made with a blend of natural oils and chemicals, it can be used on all outdoor hardwood furniture except oak. In fact ironically, it's not the best choice for teak either. On all other hardwoods it can prevent wood from splitting and warping by replacing the natural oils that are lost through weathering. It penetrates into the wood pores to offer a good level of protection and durability. It will also provide some UV and water protection, which can help slow colour changes, as well as minimise shrinking and swelling of wood. However, teak furniture in particular which has been teak oiled can be prone to developing black spots. Teak is already so rich in its own oils that it can struggle to absorb teak oil which can then result in mould and mildew growing on the excess oil. The advice seems to be to ensure that teak furniture is very clean and dry before applying any teak oil, so that you’re not trapping in mould or moisture.
Plia Parasols are made from eucalyptus wood and are given a light coat of teak oil during the production process.
Danish Oil
This is made from a similar blend of oils and chemicals as teak oil, but is generally better suited to indoor furniture. Teak oil tends to dry to a matt finish, whereas Danish oil dries to a satin / semi-gloss finish.
Linseed Oil
Linseed oil is less preferable than teak oil as it is more likely to have a darkening effect on wood, and it develops a yellow hue over time. It is also less hard wearing than teak oil, meaning it can be scratched off more easily, removing it’s protective qualities. Save this one for interior woods.
Tung Oil
This is a totally natural product (unlike teak and Danish oils). This would be the best oil to use on outdoor teak furniture. It is also great for exterior oak. It takes longer to dry than teak oil as it doesn’t contain solvents, but it also doesn’t darken or discolour wood.
Varnish
Varnishes offer the toughest coat of protection, but with the least natural finish. If you want to apply a varnish on furniture that has previously been oiled or waxed, you’ll need to use an oil-based varnish.
Wood stain
These products offer colour, but no protection.
Wax
Waxes tend to sit more on the surface of the wood, rather than penetrating the surface as oils do, and so are typically not hardwearing enough for outdoor furniture.
Which is the best oil for outdoor wood furniture?
The summary of the above is that teak oil is best for hardwood, except teak and oak outside furniture, where tung oil is the best choice.
That said, you might not need to use an oil at all. Start caring for your hardwood with a spring time clean (use a restorer if needed), and a protector product if you’d like to try and maintain a golden rather than silver colour. If you feel your wood is particularly dried out and might risk cracking, give it a small drink of oil.
Storing wooden garden furniture over winter
One of the best ways to protect and care for your garden furniture is to give it some sort of cover or storage over the winter months.
If you have the luxury of space in a garage or shed, that is the optimum place to store your garden furniture and increase its lifespan. The beauty of hardwood is that you don’t have to be overly precious with it if you don’t have the space to do so. A great alternative is a cover made of a waterproof material. Whilst breathable covers may seem the smart choice for wooden furniture, these do allow some water to penetrate, particularly where there is contact. Your best bet is a fully waterproof furniture cover, that allows some air circulation from the underneath edge.
If you find mildew patches on your wooden furniture when you uncover it, as well as trying chemical cleaners, you can try a mix of water and bleach or water and vinegar. Do test either of those in a hidden area first.
If your wooden furniture is staying outside over winter, consider raising it off the ground, if the ground it sits on is particularly wet or if water pools in that location. Even if your furniture has been treated to be extra weather resistant, it’s highly unlikely that the undersides of the feet will have been protected, so the feet are particularly prone to soaking up puddled water. (You'll find Plia parasols have an aluminium sleeve wrapped around the bottom of the pole. This ensures that even if the pole sits in water, it won't swell and get stuck in your parasol base tube.)
I’m sure it goes without saying, but as a reminder, try to lift rather than drag furniture when you're moving it. This will help to keep joints strong and avoid wobbly furniture. After all, following your furniture spring clean, you'll want to be able to flop down and enjoy your garden.