What should go at the bottom of garden bed?

Question

Good day,

I am planning to put a garden bed 400mm high to grow veggies. What should go under the bed - gravel/mulch/cardboard etc? Idea is to protect the plants at the same time have enough space for them to grow (would be planting curry leaves plant)..

Thanks,

JacobZ · Answer

Hi @kalyany,

Drip irrigation or micro sprayers, depending on what you're planting will be your best bet in a situation like this as they require relatively low pressure and are simple to set up yourself. Check out Installing Irrigation Sprayers And Drippers for some guidance on the process.

If you were only planting curry leaf plants, then you could simply run an irrigation line around the garden bed with a dripper at each plant.

If you could draw up a basic top-down sketch of the garden beds, with some measurements, the location of your tap, and the likely location of your plants then I could certainly assist you to come up with a basic layout and the materials you would require.

Let me know what you think and if you have further questions, please don't hesitate to ask. I will assist further when you can get back to me.

Jacob

kalyany · Answer

Thanks - since I am doing a new one - thinking of adding irrigation pipe line as well - that they wouldn't be connected to the water source immediately. What is the best way- it is a U-shaped garden bed - 19m width and 8m on sides. Thanks

JacobZ · Answer

Hi @kalyany,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

You might like to start by checking out @Noelle's article on How to fill a raised garden bed as well as our Best Advice article How do you fill a raised garden bed?

Generally, you should have a layer of high-quality garden soil that is at least 300mm thick, with 50-100mm of mulch on top.

Assuming your garden bed is over natural soil, you don't necessarily need to add gravel, but it can be helpful with drainage and weed suppression, so it is worth considering if the existing soil doesn't drain particularly well. Generally, you would want a layer around 100mm thick, so, due to the height limitation, you would need to dig out beneath the base of the garden bed to include it.

If you weren't concerned about the drainage at present, I wouldn't worry about using gravel. Instead, add a layer of drain matting or weed mat, and top this with 50mm or so of mulch, with pine bark or hardwood mulch being good options. This will further help to reduce weed growth, and over time will break down releasing nutrients into the soil.

You can then fill up the rest of the garden bed using a high-quality garden soil and top it with a layer of soft mulch such as sugarcane or straw to help retain moisture and regulate soil temperatures.

Check out How To Grow Vegetables for some further guidance.

Let me know if you have any further questions.

Jacob