How to Make Your Wooden Garden Beds Last For Years
So you’re ready to start a garden and you’re considering buying wooden garden beds but you’re worried they will rot and look ugly? Let me stop you there!
Wooden gardens beds are a natural resource so they will start to breakdown and decompose but not for a while! Typically, wooden garden beds last anywhere from 5-10 years but they can last longer if you follow the steps below to help preserve them.
Different Wood Types
In New Zealand, we have a few different types of wood that can be used for making raised garden beds. It’s important to choose one that suits your needs and aesthetic.
Macrocarpa
Known for its anti-rot properties, macrocarpa wood is a gorgeous golden brown colour. Macrocarpa is also soft, durable wood that will last 10-15 years once milled. You can get macrocarpa at select hardware stores or you can find it at specialty timber mills. Ask your local hardware store if they stock it.
Radiata Pine
Radiata pine wood is a versatile, plantation grown wood. Its lighter colour is perfect for fences, decking and garden beds. Radiata pine can be used for a variety of outdoor building projects. You can find radiata pine wood at most hardware stores in New Zealand.
Treated vs Untreated Wood
There’s a strong debate between using treated wood and untreated wood for your raised garden beds.
Treated wood gets its name from being treated with chemicals to preserve the wood and make it last longer. The chemicals seep deep into the wood grain and make the wood pest-free.
Untreated wood is wood that is in its natural state. It gets milled into a wooden plank shape but it has not been treated with any chemicals.
In my opinion, it’s better to use untreated wood as nothing leeches into your soil and you can control what you put on it. Untreated wood is a better choice for the environment. The more natural your garden is, the more likely that insects likes bees and butterflies will frequent your garden.
Untreated wood is also good if you’re planning to stain or paint your garden beds (with natural stains/paints). The wood is essentially a blank canvas so you can decorate and protect it however you want.
If you’re not worried about what is going in your soil and plants or you are on a budget, treated wood may be your best option. If possible, try sourcing wood that has been naturally treated or ask your timber specialist what they used to treat it to ensure it is food safe. You do not want harmful chemicals leeching into your soil and plants that you will then eat.
My Top 3 Tips for Looking After Your Garden Beds
Buy the thickest wood you can afford.
Think of your garden bed as a wall. It’s holding in all the soil and plants and without it, everything would be lying on the ground. Therefore, you want to have the strongest wall possible to make sure your garden stays upright and lasts as long as possible.
I recommend buying wood that is at least 3cm thick. The thicker your wood, the slower it will decompose and the stronger your garden beds will be.
Place your raised garden beds on top of pebbles or stones.
The biggest mistake I see new gardeners make is putting their garden beds directly on their lawn. When you do this, your dry wood garden beds are going to slowly start absorbing the water and moisture that is in your grass which can lead to your garden beds rotting quicker over time. If the beds are always on a damp surface, there is no way for them to dry out and they will keep rotting until you have to replace them.
I recommend placing your garden beds on a surface of pebbles or stones. This acts as a natural draining system and helps elevate your garden beds off the damp grass. When you water your garden (or if it rains), the excess water not absorbed by your garden will simply drain through your soil, through the pebbles and into the earth below. This layer will keep the bottom of your garden beds clean and dry and prevent excessive rotting or discolouration caused from water damage.
Stain your garden beds.
Another great tip to preserving the lifespan of your wooden garden beds is to stain them. I like using an eco stain, something that is natural and won't seep into my soil and plants. I like to do a few coats on the inside and outside of my garden beds before the soil goes in to ensure everything is sealed. An eco stain will help keep moisture out of the wood and slow down decomposition.
A stain is a great option if you live in an area that gets excessive amounts of rain or if your garden is in a shadier spot that can’t dry out much.
I hope these tips help you and make you feel confident in choosing wooden garden beds. I’ve had steel garden beds and I’ve had macrocarpa garden beds and I can honestly say that there is nothing quite like the look of wood.
Happy gardening!