How to reuse soil from your old grow

We often get asked about whether our customers can reuse their growing media – the answer is ‘yes’! Your substrate can definitely be reused as a base potting mix for your next grow.

Advantages

There are many advantages to this, including:

• Money: you can recycle and reuse your soil over and over again.
• Ease: once you’ve got a super-healthy medium, you just need to add to it ever-so-slightly with our products between cycles.
• Environment: using natural products eliminates the need for synthetic fertilisers which have long-term negative effects on our environment. Nitrogen- and phosphate-based synthetic fertilisers leach into groundwater and increase its toxicity, causing water pollution and disrupt aquatic ecosystems.

Also, by reusing your soil from your previous grow (which may well be peat-based) you are reducing the negative environmental impact of peat extraction with all associated carbon emissions (see our post here for more info on this).

The process

There aren’t any hard-and-fast rules for this; a lot of it depends on personal preference, as well as what works best for your plants. The following guide is a general walkthrough: keep what works best for you, and discard what doesn’t.

1. Pull out any plants remaining in your substrate (and try and get as much root as possible).
2. Purchase some good, light mix soil or some coco to fill your pot back up. If growing in soil, remember that you don’t want anything that is too nutrient dense (or even worse containing ‘slow release’ fertilisers) as it will be too hot. (Although if you are using a light mix soil, it is likely to contain peat, but you will be using less than if you were starting afresh, so there is still a benefit in reusing.)
3. Replenish the medium with a dose of Grow and Wormcasts (and Bloom if growing automatic varieties) as many of the nutrients from your previous grow will have been absorbed by your last plant. Grow provides a hefty amount of Nitrogen and Phosphorous and Wormcasts also add valuable humus – this not only holds extra water—which will keep your soil from getting too moist - but it also provides tons of nutrients to the plant and helps with airflow. Other products like coconut husk, rice hulls and lava rock are also great. You could also add more perlite to encourage aeration.
4. Water the mix thoroughly, then leave for 2 weeks and you are good to go!

Creating your own Recycled Organic Living Soil (ROLS)

Another way that a grower can go with their soil is to develop Recycled Organic Living Soil. We will be updating our customers about how to go about this in another post soon!