Feeding Microbes Molasses for Soil Health

Soil health is so important as it helps us to not have to spend as much money on fertilizers and pest control.  It is a good idea to take a soil test of your flower beds every two or three years.  You can collect soil samples from several spots in your flower beds and send the samples to your local county extension office or use a home testing kits for results.  I use compost a lot to amend my dahlia beds, so my phosphorus and potassium levels are usually a little high.  I just need a little nitrogen.  Compost improves soil structure and promotes beneficial microbes, making it a great amendment for flower beds.  If I use fertilizer, I like Espoma Plant Tone (5-3-3) as it does not have high percentages of NPK.  This product is easily available at my local stores.  It has 5% nitrogen, 3% phosphorus, 3% potassium, calcium, magnesium, and sulfur.  I mix it into the top one inch of soil.  Espoma Plant Tone is a balanced fertilizer that supports healthy growth without overloading the soil with nutrients which is ideal for dahlias.  I like to know my pH as dahlias like a pH around 6.5 to 7.0.  Soil tests let you know your pH and level of phosphorus and potassium so you can choose the right fertilizers and ensure your plants can absorb nutrients effectively.

I do use fish and seaweed products as a foliar to keep my dahlias healthy and keep pest pressure down.  Foliar spray is where you are applying a liquid solution directly to the leaves of the plant to deliver essential nutrients.  I have heard about organic farmers growing high brix plants.  A brix value of 12 or higher usually indicates a healthy plant and will keep most insects from recognizing the plant as food.  When you take a Brix reading, you are measuring the amount of sugar in plant juices.  I have a blog about “Using Brix measurements for pest management in my dahlia garden” if you would like to read more about increasing sugar levels in your plants.  To help my dahlias achieve high Brix levels and resist pests, I focus on feeding soil microbes with molasses.  Soil microbes are living organisms like bacteria and fungi.  They stimulate plant growth and help plants resist the stress of diseases and be more resilient.  I use two tablespoons of unsulfured molasses to one gallon of water.  I use unsulfured molasses because sulfur dioxide may be harmful to some beneficial microorganisms.  I apply it around my dahlias at the base of the plant.  I use a 2 gallon battery operated garden sprayer.  I try to spray molasses every three weeks during the growing season from May through July.  I have noticed that my dahlias are less affected by aphids and other common pests.  Insects do not like plants with high sugar levels.  Once the dahlias are in full bloom in August, I normally stop using foliar spraying as the plants should be strong enough to resists pests.  At that point, I have more pollinators that can help with pest control.

This year I am also trying dry molasses to add more organic matter to my soil.  I will add two tablespoons of dry molasses and mix into the soil when I am planting my dahlia tubers.  Dry molasses is a slow release non burning carbon source which feeds the beneficial microbes.  Microbes break down organic matter to release essential nutrients in a form that plants can absorb.  Microbes improve the soil structure and help your plants be healthier and increase the plant’s sugar level.  The higher the sugar level of the plant, the less insects bother the plant.

I found 50 pounds bags of dried molasses at my local farm and garden supply store.  Molasses is a byproduct of refining sugar cane or sugar beets into sugar.  It is used in livestock feed so it can be a mix of dried molasses from sugar cane and sugar beets.  If you cannot find it locally, I have seen bags for sale online.  You may want to check your local feed stores as dried molasses is used in cattle and horse feed to improve taste and boost energy.  I have read online that the application rate for dried molasses is 10 to 20 pounds per 1000 square feet.  It is recommended for shrubs and roses to apply in early spring and again in the fall.  You spread 5 to 6 pounds of dried molasses per 100 feet of bed.  You do need to rake it lightly into the top one inch of soil.  Afterwards, you need to water it into the soil.

You do not have to use it at planting time, you could use it after you plant the dahlia; however, it appears you do need to work the dried molasses into your soil for the microbes and lightly water it in to distribute it into the soil.  When I was researching dried molasses online, I did see other gardeners using more of the product; however, I am just going to try 2 tablespoons per planting hole.  I do not want to overstimulate the microbes.  I did read where some gardeners were using dried molasses in their potting mixture for their cuttings and seedlings before they planted them outside.

 Molasses is just another source of organic matter for microbes.  Molasses is used in compost teas and is also a compost enhancer and activator.  Compost, leaves, cover crops, and wood chips are other forms of organic matter.  Organic matter is going to improve the soil structure and increase the availability of nutrients for healthy plant growth.  Some microbes secrete plant nutrients that stimulate root growth.  A healthy population of microbes can help with plant diseases.  You may want to give molasses a try as feeding soil microbes is essential for soil health.  Like with most things in life, you do not want to overdo adding molasses to your soil as it can disrupt the soil balance which may make it hard for plants to absorb nutrients.