I’m hoping you can assist me with this. I’ve topped up my container garden (photo included) this year with triple Blend/mix BC I wanted to beef up the nutrients for my vegetables–tomatoes, peppers, and melons/cucumbers.
Before I plant, I wanted to ask if I should add anything to the mix, such as more peat or coarse sand?
The blend I bought says it consists of: humus, sphagnum peat moss and compost
The Toronto Master Gardeners Container Gardening Guide provides guidance regarding soil for containers. Ideally you should use a light potting soil because soils in containers have poorer drainage characteristics.
A previous post from Toronto Master Gardeners goes into great detail about why triple mix (aka “garden soil”) is not ideally suited for container gardening. To lighten up your triple mix, you should amend it with other materials. The links below have useful information on creating your own potting media, including this Fine Gardening link which suggests a mix of equal parts triple mix (“garden soil”), perlite, peat moss and compost along with several other amendments in smaller quantities. A University of Illinois Extension suggestion is one part garden soil, one part peat moss and one part perlite or coarse builders’ sand (not fine sand like play sand). Note that as peat moss is a non-renewable resource, Toronto Master Gardeners recommends reducing peat moss use if possible. You can read more about alternatives on this TMG post about peat moss.
Other resources for creating your own potting mix:
- Do it yourself. Creating the Right Soil Mix for Square Foot Gardening.
- University of New Hampshire Extension. What is the best way to grow potatoes in containers?
- Homemade Potting Media (psu.edu)