Even if you’ve never heard of lactic acid bacteria, known more simply as LAB, these friendly microbes play an essential part in your daily life. They live in the human digestive system and help extract nutrients from food. They also work hard in the garden, cycling soil nutrients and fueling growth.
Just as people take probiotics to populate their bodies with beneficial bacteria, gardeners can positively influence the microbiome of their plants to improve vigor and productivity by applying homemade LAB. Using them as a foliar spray or root drench can help to protect plants from disease, give them better access to nutrients, and facilitate superior yields. Discover why LAB are such a practical organic input, how to make them easily at home, and how to apply them to your plants.
Lactic Acid Bacteria as a Biofertilizer
As a biofertilizer, LAB enhance the growth of plants by boosting the supply of available nutrients. These bacteria release a cocktail of enzymes into the soil and accelerate the breakdown of organic matter, such as decomposing plants and other microbes. In speeding up this natural cycle, LAB liberate bound nutrients and make them available to living plants. Adding these beneficial microbes to your soil will reduce the time it takes for compost, organic fertilizers, and mulches to impact crops positively. LAB also add fertility to the soil. As living microbes, they accumulate nutrients such as nitrogen. Predator species in the soil food web, including nematodes and earthworms, consume these bacterial cells and excrete nutrients in a plant-available form.
LAB as a Biostimulant
Agriculture increasingly uses biostimulants to improve nutrition efficiency, stress tolerance, and crop quality. As a biostimulant, LAB produce enzymes to digest their food and manufacture plant hormones. These substances can alter the physical properties of plants, including root and shoot length. In addition to freeing up nutrients in the soil, these microbes drive plant proliferation by serving as a source of growth-stimulating hormones.
LAB Helps to Fortify Plant Defenses
Pests and diseases are two of the biggest challenges gardeners face throughout the growing season. Fortunately, LAB provide an organic approach to dealing with some of the most common problematic insects and pathogens. Research has shown that LAB act as a biopesticide against certain nematodes and winged drosophila—an insect that targets soft fruits such as strawberries and raspberries. Applying LAB can also be a potential treatment for late blight on potatoes and fusarium on tomatoes. These friendly microbes are helpful in these situations because it’s in their interest to compete for food. LAB churn out substances such as bacteriocins that inhibit the growth of other bacteria and fungi to establish dominance in specific niches throughout root zones and leaf surfaces.
LAB and Germination Optimization
Soaking seeds in a LAB solution can help gardeners gain an edge at the start of the growing season. These microbes induce germination and quickly inoculate emerging tap roots and shoots. Through their action as biostimulants, they drive the early growth of tissues. As biopesticides, they combat common seedling diseases, such as fungi that cause damping off.
How To Make LAB for your Garden
LAB have a long list of benefits when used in grow rooms and gardens. Thankfully, it doesn’t take much to make them at home and put them to use. Discover a simple step-by-step recipe below to make LAB in your kitchen:
- Soak rice grains and strain the cloudy water into a clean jar, making it roughly 1/6 full.
2. Cover with a paper towel and a rubber band or piece of string. Write the date on the paper towel with a marker pen.
3. Place the jar in a cupboard at room temperature, away from direct light, for three days. During this time, the solution will develop a slightly sour smell—a surefire sign of microbial activity.
4. After three days, pour in enough milk so the total amount of liquid fills the jar by 4/6, leaving the culture enough room to expand in the coming days.
5. Secure the paper towel back over the top of the jar and place it in the cupboard for three to five days more.
6. The mixture will separate into yellow liquid and white solid fractions. Strain the yellow liquid into a clean jar and place the solid fraction into your compost pile.
7. Loosely cover the jar with a lid and store your LAB solution in the fridge until you’re ready to use it.
How To Use LAB on Your Plants
Dilute your LAB before using it in your grow room or garden. Add water at a ratio of 1:1000, or 1ml per liter, before applying it as a root drench, foliar spray, or seed-soaking solution.
