The first thing to remember is that wood is natural and the appearance of wood will change when left outdoors. This is part of the natural process of protection which the wood undergoes as it acclimatizes to being exposed to the atmosphere.
Do not use a cheap plastic cover as this will be counter productive and will, in fact, cause more harm than good. When using a cover, please be sure to arrange it so that the centre of the cover is higher than the sides so that rain water runs off.
This patina or silvering is unavoidable. However, the process can be slowed and the original colour of the wood maintained by applying teak oil sparingly once or twice a season. Applying teak oil with a lint free cloth will slow the process of weathering and might help to minimise surface cracking.
Re-applying teak oil can only be done when the dirt which has built up over the season is completely removed by with warm soapy water and a good brush. Once the furniture has dried, you could lightly sand any rough areas. Black areas may appear where the oil and dirt have mixed if the dirt has not been removed prior to application.
To keep the original colour of your furniture longer, you can apply teak oil can be applied sparingly using a lint free cloth once or at most twice a season. This treatment will slow the weathering process and could also minimise surface fissures.
Before re-applying teak oil, it is essential that any accumulated dirt is removed by scrubbing with a stiff brush and soapy warm water. When the furniture has dried completely, rough areas may be lightly sanded. If the dirt is not removed before treatment, black areas will appear on the surface where the oil and dirt have mixed.
Finally, pay particular attention to the end grain and to any hidden surfaces when applying the oil. Also look carefully at any joints or services. Excess oil should be wiped off with a clean lint free cloth. To protect your clothing, please ensure that the teak oil has dried fully before using the furniture!
To recap:
To summarise:
* Allow the furniture to dry completely
* Dry the furniture completely
* Sand rough surfaces
* Pay close attention to the end of the grain and to the joints
* Ensure the joints are given extra treatment
* Wipe away excess oil
* Repeat once or at most twice a season
NOTE: If the dirt is not removed before treatment, black areas will appear on the surface where the oil and dirt have mixed.
So, if you want your garden furniture to avoid the worst ravages of the weather, then the ideas John Duff of Garden Furniture Scotland has outlined might help.