Watering Living Soil: How to Master Moisture Management
Watering Living Soil (Moisture Management)
Introduction
Watering living soil is both a science and an art. Unlike inert media, living soil is a biologically active ecosystem filled with beneficial microbes, fungi, and organic matter that work together to feed your plants. Maintaining optimal moisture is critical — too much water can suffocate roots and microbes, while too little can stall microbial activity and reduce plant growth and yield. Unfortunately, very few resources clearly explain how to water living soil correctly, especially for home growers.
Living soil systems are particularly sensitive to moisture extremes because they rely on microbial life for nutrient cycling. Unlike synthetic systems that buffer with salt-based nutrients, living soil requires stable hydration to support active biological processes.
This guide will walk you through the fundamentals of watering living soil so you can avoid beginner mistakes and build a thriving growing system.
1. Understanding Moisture in Living Soil
Living soil thrives on consistency. Microbial activity — the core of nutrient cycling — depends on soil staying evenly moist, not saturated and not dry. In living soil, moisture also helps regulate temperature, enables root exudate exchange, and facilitates oxygen diffusion in the root zone.
The goal: Keep soil moisture in the microbial sweet spot — consistently damp like a wrung-out sponge.
2. How Often to Water Living Soil
A general guideline for watering living soil is to apply water equivalent to 5–10% of the container volume. For example:
- 30L pot: 1.5 to 3L per watering
- 100L pot: 5 to 10L per watering
Larger containers with smaller plants can go several days between waterings, while small pots or high-heat conditions may require daily checks. Watering needs will also evolve throughout the plant’s lifecycle — seedlings, vegetating plants, and flowering stages all have different uptake patterns.
Important factors:
- Container size
- Plant maturity and growth stage
- Environmental conditions (heat, wind, humidity)
- Mulching practices
3. How to Tell When It’s Time to Water
You don’t need fancy gear to monitor soil moisture — though it helps. Use a combination of simple and advanced methods:
Finger Test
Stick your finger 2–3 cm into the soil. If it feels dry, it's time to water. If it feels moist and cool, wait a day.
Pot Weight Test
Lift the pot to get a sense of its weight when wet vs. dry. This becomes intuitive with practice.
Visual & Plant Cues
- Drooping leaves even in moist soil = overwatering
- Dry soil pulling away from pot edges = underwatering
- Dark green foliage and steady growth = healthy balance
4. Measuring Living Soil Moisture: Tension vs. Volume
Not all water is equally accessible to plants. Some water is tightly bound to soil particles, while some is readily available for root uptake.
🧪 Soil Moisture Tension (mbar)
Moisture tension reflects the amount of suction pressure roots must exert to access water, measured in millibar (mbar). This is the most biologically relevant measure for living soil.
Blumat Digital Moisture Meter is the go-to tool here. It gives precise readings that tell you how hard your plant has to work to take up water.
Ideal tension ranges:
- 0–30 mbar: Too wet (risk of anaerobic conditions)
- 40–120 mbar: Ideal range for microbial and plant health
- 130+ mbar: Too dry, microbes slow down, plant uptake stressed
Unlike VWC, tension shows what your plant is experiencing — not just how much water is in the soil.
📏 Volumetric Water Content (VWC)
VWC measures the percentage of total soil volume that is water. For example, 30% VWC means 30% of the soil’s volume is water. Tools like TDR probes and capacitance sensors are used for this.
Limitations: VWC doesn’t tell you how easily plants can extract that water. Two soils can have the same VWC but very different water availability depending on texture and structure.
5. Tools & Tech for Better Watering Living Soil
- Blumat Digital Moisture Meter: Instant tension readings. Use readings to accurately guide watering events. Aim for a range between 50 and 80 with young seedlings and clones and 60 to 120 for mature plants. Observe soil properties and plant health when maintaining watering in these ranges as it will become more intuitive as you practice.
- Blumat Irrigation System: Passive, plant and soil-responsive irrigation. This is the best irrigation solution for living soil media. Blumat systems achieve consistent soil moisture which encourages an optimal environment for beneficial soil biology. It can be setup with a gravity fed reservoir or scaled up to any size system using a pressure reducer on a mains water source. Ensure the Blumat carrots are installed when the soil is evenly moist to ensure accurate function.
- Drip Irrigation Systems: Consistent moisture, especially in warm climates. This requires careful configuration of timers to ensure the right amount of moisture is being delivered over time.
- Moisture Probes (VWC): Helpful if calibrated for your soil type. Correlate VWC to tension for your soil. Bluelab Pulse Meters are excellent for taking accurate VWC, EC and temperature readings, particularly with growing media such as our Living Soil blend.
6. Mulching for Moisture Retention
Mulching is essential in living soil systems. A light layer of organic mulch (straw, wood chips) helps:
- Reduce evaporation
- Regulate soil temperature
- Protect microbial habitat
- Suppress weeds
Tip: Use mulch in all containers and beds to improve moisture consistency. Avoid sources that may contain weed seeds or other contaminants.
7. Common Watering Mistakes in Living Soil
- Overwatering compost-rich mixes: They hold water longer than they appear to
- Letting soil dry out completely: Reduces microbial populations and disrupts nutrient cycling
- Frequent shallow watering: Encourages shallow roots and moisture layering
8. Final Tips for Watering Living Soil
- Water deeply and less frequently in larger containers.
- Always monitor soil conditions before watering.
- Use tension-based measurements to determine when to water or when not to water. Blumat Digital Moisture Meter is the perfect tool.
- Adjust your watering routine for seasonal changes and plant stages. Young cuttings or seedlings will not need much water at all. As they develop, their watering requirements will increase.
- Water early in the day to minimise evaporative loss and reduce pathogen risk.
- Install Blumat irrigation. This is the best solution for living soil irrigation as it is plant and soil driven watering via tensiometer irrigation valves.
With practice and the right tools, you’ll learn to read your soil’s signals and maintain the perfect moisture balance for thriving plants and active soil life.
For more insights, check out this BuildASoil watering guide and this KIS Organics irrigation study.
Need Help?
Need help troubleshooting your soil or irrigation setup?
Feel free to contact Easy As Organics — we love helping growers succeed with living soil. We can assist you with Blumat irrigation for a grow of any size, from 1 plant to commercial greenhouses.
Soil Life Summit Insights and Innovations from Industry Experts in Organic Living Soil Cultivation
Attending the Soil Life Summit in Nevada City was an amazing opportunity to learn from some of the top experts in commercial organic living soil cultivation. The event brings together notable individuals and business representatives in the industry to discuss the latest innovations and practices in organic crop production. In this article, we'll provide insights into some of the key speakers and their presentations at the Soil Life Summit. The 2 day conference was organised by Grassroots Fabric Pots and was very professional with full catering by awesome local food vendors as well as a seperate industry expo area
Key Speakers and Presentations: Bill McKibbon, from Logan Labs, spoke about the importance of soil testing and analysis in developing a comprehensive nutrient management plan. He emphasized the significance of understanding the specific needs of each crop and tailoring soil amendments accordingly. Bill provided an effective method for taking samples from field soil and growing media to obtain the greatest level of test accuracy.
Casey and Kisha from Catalyst Bioamendments presented innovative techniques in broad-acre application of biocomplete compost extracts. Their methods of composting and extracting the beneficial microorganisms present in the compost can be used to improve soil health and plant growth. Many large scale regenerative farmers across the USA have benefited from these biological inoculants contributing to lowered pest pressure, healthier, more resilient plants, and greatly reduced fertilizer requirements.
Scott Wall and Jenny Garley from New Age Laboratories specialize in sap testing as a tool for growers to monitor real-time plant nutrient uptake and movement. They stressed the importance of understanding how plants take up nutrients from the soil and how the plant then uses the nutrients for energy production. Using this data, nutrient uptake bottlenecks and deficiencies can be avoided by making informed nutrient application decisions before the deficiency occurs.
Michael, Izzy, and Cooper of Sustainable Village presented groundbreaking new methodology around plant and soil-driven automated irrigation. Their approach saves water, labor, and ultimately increases plant health and yield.
Tad Hussey and Ben Higgins of KIS Organics emphasized the importance of researching and testing new products before using them in a garden or farm. They also explained a high-level model of biological succession over varying timescales based on the type of species and how important it is to protect microbial populations in soil for healthy crops.
Steve Cantwell closed the event with an inspiring life story of his journey from becoming a successful MMA fighter to owning and operating a permaculture-based no-till indoor cannabis facility. The facility, Greenlife Productions, is a no-waste facility, composting all green waste and returning it to his raised beds as well as using all waste water from his dehumidifiers and air conditioning. Steve explained his application of permaculture practices in his indoor organic facility that include the use of specially selected covercrops in certain areas of his raised beds that trap pests, keeping them away from the primary crop for later removal from the operation. He’s expanded his business to start Greenlife Produce, a no-till, regenerative vegetable farm, which is also DEM Pure certified, serving his local area of Pahrump, Nevada with the highest quality, organic vegetables.
Attending the Soil Life Summit is an excellent way to learn from industry experts and gain insights into the latest practices and techniques in organic living soil cultivation. The event provides an opportunity to network with like-minded individuals and learn from the best in the business. Personally, I gained so much from spending time with experts in commercial organic crop production and have applied some of the knowledge to my growing media and methodology already. If you're interested in organic living soil cultivation, be sure to attend next year's Soil Life Summit.
Vegepod gardening with living soil
Vegepod raised garden beds and Living Soil: The ultimate compact veggie growing combo.
The popularity of home vegetable gardens continues to grow, as fresh and frozen food prices soar in Australia. With labour shortages, the rise in costs of fuel, fertilisers and freight as well as the recent floods have seen the price of fresh foods like broccoli rise by 75% between March and April.
More people have turned to growing their own where sales of vegetable seedlings increased by 30% from 2020 to 2021 across Australia. Starting a vegetable garden, no matter how big or small, is a great way to reduce reliance on food from supermarkets, improve health by getting active outdoors in the garden while consuming nutrient dense foods grown in rich, organic living soil. One of our awesome stockists, Fran's Hydroponics have curated some easy and effective vegepod raised garden bed kits to get you growing your own veggies right away.
This method of vegetable growing is great for people with busy lifestyles. You don’t need much space and can easily set up on small balconies and back yards. Vegepod Australia have designed a high quality and effective sub irrigated planter system so you only need to provide the growing media, vegetable seedlings, water and sunlight.
Sub irrigated planter beds only require filling a reservoir with water at the bottom of the bed. The soil will wick the water up into the root zone as it dries via capillary action. This action increases or decreases based on plant needs and environmental conditions.
Read the full article from Fran's hydroponics for a complete guide on getting the most from your small, back yard veggie garden.
Insect Frass for improving plant health.
Insect Frass, a sustainable plant nutrient product
Black soldier fly larvae frass - their solid digestate - is the only substance to contain a form of chitin that is plant available. This chitin produces antimicrobial compounds in stress conditions that act as a protective barrier. The chitin blocks pathogenic organisms and their access to mineral nutrients while blocking the release of pathogenic mycotoxins.
The role of biology in nutrient uptake, ecosystem biodiversity and resilience as well as plant immune response to pests and disease is becoming more studied and understood. Cultivators are looking to inputs that will support this living soil system known as the soil food web that maintains soil structure, mineralises organic nutrients into plant available form and outcompetes pests, pathogens and disease. Insect frass is an incredible organic fertiliser that not only supports and stimulates the soil food web while providing plant available mineral nutrients but also contains itself, huge levels of biology in all beneficial functional groups.
Unlike chemical N fertilisers that burn carbon into the atmosphere and pollute waterways, Insect Frass stores carbon and nitrogen directly in the soil. Frass prevents atmospheric loss of nitrogen via its bacteria. Nitrogen fixing bacteria in frass such as Bacillus and Pseudomonas fix atmospheric nitrogen while other nitrifying bacteria convert the N in soil to plant available form to optimise photosynthesis. Frass contains the biology needed to help optimise the nitrogen cycle and keep the nitrogen in the soil.
Insect frass contains very low levels of heavy metals, sodium and other chemicals which can accumulate in plant tissue and the environment as well as causing undesirable soil conditions. Frass is an excellent input to use in place of chemical or high sodium organic fertilisers not only due to the presence of all major nutrients vital for plant growth but its incredible defense properties for plants.
Rates for deficient or low fertility soils can be higher, up to 500kg per hectare (500g per square metre). Below are some best practice application rates for various growing systems and styles.
Garden beds: Spread 100 to 250g per m2 and gently incorporate into the soil before planting and again after seedlings are established. Apply mulch on top to maintain moisture.
Top dress: Sprinkle a handful around the rootzone. Water in to activate.
Fertigation/root drench: Add 2 Tbsp 9L water.
Potting soil: Apply and mix at 1.5% to 2% or 15-20mL per litre of potting media.
Hydroponics: Top dress directly to any grow media (rockwool, coco, hydroton) or add 1/2 cup per 100L of water (strain for drip systems). For best results, brew insect frass tea for 24 hours before use. Add directly to the reservoir for flood to drain systems.
To conclude, frass is a highly effective and affordable, long lasting fertiliser that will improve soil biological diversity, soil fertility, increase plant yields and defend against plant pathogens while minimising environmental impact.