What to fill raised garden beds with?

Raised garden beds offer numerous benefits for vegetable cultivation, including improved soil drainage, better pest control, and easier maintenance. To optimize vegetable growth in these beds, it’s essential to focus on creating a nutrient-rich environment that supports plant health and productivity.

Although soil mixes are ultimately determined by what you intend to grow and it is important to note plants have different soil requirements, we recommend a simple mix to get started that keeps soil pliable and free draining.

Raised hardwood timber garden beds are great for growing a variety of vegies, herbs, flowers, and even small fruit trees, as they allow you to vary and separate your soil for each purpose but here is a basic fool proof method…

Root vegies like a sandier mix and less composted material. For these we would recommend a 40/60 mix of course river sand to compost (this is your base mix). Most landscape supplies will kindly mix this through for you. For growing most garden greens, we recommend 30/70 mix of course river sand to rich composted material (this is your base mix). For best results with leafy greens and bracciaes, add an extra 50mm or so layer of rich composted matter to the top of the base mix without mixing through. Then cover with 70-100mm of mulch (straw is best). Always put seedlings in last bedding them down into this compost and mulch top layer for a great start. The compost will fertilise and keep the seedlings moist until they establish and the mulch will protect the seedlings from frost in winter and provide further moisture retention in the hotter months.

Tip:

Soil Liner: Consider using a soil liner, such as landscape fabric or cardboard, at the bottom of the raised bed to prevent weeds from infiltrating from below while still allowing water drainage. A soil liner helps maintain a clean planting environment, reduces weed competition, and prolongs the lifespan of the raised bed structure.

Mulch: Apply a layer of organic mulch such as straw, shredded leaves, or grass clippings to the surface of the soil. Mulch conserves moisture, suppresses weed growth, moderates soil temperature, and enhances soil structure as it decomposes. Additionally, organic mulch provides a habitat for beneficial organisms like earthworms and encourages a healthy soil food web.