Mixing sand with your potting mix will help it to maintain its structure for longer. It is fantastic for plants that you want to keep in the same pot for more than 2 years. Adding coarse sand to your potting mix will slow down how quickly the level will drop and keep the plant stable. Use a 1 part coarse river sand to 3 parts potting soil mix for large plants including fruit trees and bird of paradise.
The type of sand you add to potting mix is important. Avoid using fine, sandpit or builders sand but instead use a coarse sand, sometimes known as river sand.
This article will explore whether you should add sand to potting mix, which sand to choose and how much to add for the best plant growth possible.
Should you mix sand with potting mix?
You should mix sand with potting mix if you want to keep the plant in the pot for longer than 2 years, if you are planting a large plant in a large pot. Fruit trees that are large and you are planting in a large pot like a half wine barrel then adding sand in the potting mix is a great idea.
Another plant that would benefit from added sand in the potting mix is bird of paradise. These plants grow large fast and adding sand means you can keep them in the same pot for longer.
You can mix sand with potting mix when filling your raised garden bed. I have added sand to the base of my raised garden bed to improve draining. You can also mix through around ¼ of plain potting mix with
Raised garden mix usually already has extra sand added to help it to hold structure for longer.
What type of sand to mix with potting mix
The best type of sand to mix with your potting mix is coarse, river sand. You can buy it in small bags from hardware stores and garden centers. If you want larger amounts then head to a landscaping supply store and order it by the trailer load.
They usually deliver so if you are using it for raised garden beds and need lots of sand then this will be the more economical way to order.
The reason that coarse sand is best is because it is the perfect mix of large particles that will hold soil structure while still allowing water to flow through. Fine sand will let water through the potting soil too fast and the pot can dry out quickly.
How much sand to mix with potting mix
If you are using potting mix to repot a large plant including fruit trees or even smaller plants, then add up to ¼ of the mix with sand. The easiest way is to use an old pot, fill it with sand and then add 3 more pots of potting soil. This will give you a ratio of 1:4 or ¼ of the mix with coarse sand.
Mix the sand through the potting mix thoroughly. Ove time the organic material will start to break down and the level of the soil will drop. When you add sand, this will slow the rate that the level drops and keep the roots stable for longer.
When to mix sand with potting mix
Mix sand with potting mix when you are ready to repot your plant. It is easy to mix the sand and potting soil together when you need it in a wheelbarrow. If you have made too much of the sand and potting soil mix, then store it back in the potting soil back.
Best plants to add sand to potting mix
The best plants to use the sand and potting soil mix with are large plants that need a more stable base for their roots. Fruit trees including citrus grown in pots grow best when you add coarse river sand to the mix. Lemon trees, limes, oranges, apples, and pears all love to grow in a sand and potting soil mix.
When not to add sand to potting mix
It is not necessary to add sand to potting mix if you are growing seeds, or small seedlings. IF the plant is going to be in the pot for less than a year then there is no need to add sand. By the time the organic matter starts to break down, you will be transplanting it to a new pot or into the ground.
Coarse sand is also not necessary for fast growing indoor plants. Monstera and pothos than need repotting every 1-2 years will work best if they are planted straight into potting soil without the sand.
Longer growing indoor plants like sansevieria or snake plant will grow well in a sand and potting soil mix. They tend to stay in the same pot for longer
What sand should not be mixed with potting mix?
Avoid mixing fine sandpit sand for with your potting mix. This can cause the water to drain through the potting mix too fast and the plant roots can dry out. Avoid adding too much sand to the mix because the soil can lack the nutrients the plant will need to grow well.
My favorite ratio is 1 part sand to 3 parts good quality potting soil. This will support the growth of larger plants such as fruit trees, bird of paradise, palm trees and plants in raised garden beds.
Should I Mix Sand with My Potting Soil? | Summary
Mix coarse river sand with potting soil if you want to grow your plant in the same pot for more than 2 years. Use this for larger plants or those growing in pots wider than 2 feet. You can also mix sand through potting soil when you are filling raised garden beds.
Coarse river sand can be bought in bags from your local garden center or hardware store or have it delivered from a landscape supplier.
Happy growing.
I am an accredited practicing dietitian, experienced gardener and a dedicated cook. I love writing and sharing my experience so you can learn from my successes and mistakes.