Organic Soil Amendments for a Cut Flower Farm

Updated January 5, 2024

Growing beautiful, prolific cut flowers comes down to growing healthy soil. One major thing I want to get across in this post: It doesn’t matter if you are a career flower farmer or have a flower garden in your backyard just to admire – the principles of growing beautiful flowers are the same.

Healthy, organic soil filled with beneficial life is the at base of every beautiful flower garden.

That is really all you need to remember. As a gardener, you should live it, breathe it, and make it your mantra.

how to increase soil health for cut flowers

More than anything, healthy soil is the most important element of your farm or garden. If your plants are suffering (discolorations, stunted growth, wilting, attracting tons of bugs) it is because you have an unhealthy balance of soil minerals and soil microbiology. The imbalance can always be fixed, no matter what it is.

I have gone into great detail in other posts about building healthy soils and nurturing your Soil Food Web. I recommend reading the four articles below that I’ve written in detail about building healthy soil, so you have a base understanding of what you’re trying to achieve, before resorting immediately to using fertilizers…

Preventing Soil Degradation and Increasing the Biodiversity of Your Soil Food Web

5 Steps to Building Healthy Organic Soil for Flowers

Fertilizing and ‘The Law of Return’

Why Synthetic Fertilizers like Miracle-Gro are So Bad for Your Garden

On our regenerative flower farm in Western New York, we use specific gardening practices (no-till, cover cropping, etc) to encourage healthy colonies of microorganisms in the garden. This means healthy bacteria & fungi are in abundance in our farm soils, among other visible and invisible creatures that help plants get the water and nutrients they need to survive. These soil microbes are the basis of everything – literally life on earth — and it is most important for us to nurture them. If we can build a healthy system of soil microorganisms, our plants will grow healthy and prolific.

Soil Amendments for the Organic Flower Farm

On our flower farm, we use the following soil amendments to help our farm produce the healthiest, biggest, most prolific flowers year after year.

Locally-produced Compost on every bed

Adding compost is the base of every healthy soil regime. Making your own compost is best, but it would take a LOT of plant waste for us to cover our entire farm with homemade compost, so we buy it from a local dairy farmer. We wheelbarrow the compost out on each bed into piles, then use a hard rake to smooth it flat out onto the beds. We lay the compost 3 inches thick on top of the soil and we do NOT till it in. Instead of tilling, which is incredibly harmful for the soil and releases carbon into the atmosphere, we use a compost fork with large tines to aerate the soil by stepping on the fork and sticking it down into the bed every 12 inches or so down the length of the bed.

Mycorrhizal Fungi Inoculant during planting

Every plant, annual and perennial, gets its root ball dipped in mycorrhizal fungi inoculant before it gets planted in the hole. Mycorrhizal fungi is one of the most beneficial microorganism in the garden – invisible strands of hyphae grow on the plants’ roots, extending their ability to soak up water and nutrients that are not available in the plants’ immediate vicinity. Mycorrhizal fungi forms a symbiotic relationship with plants — plants provide the fungi a source of carbon for food, and the fungi go retrieve water and nutrients for the plants in return.

homemade Compost Tea spray for cut flowers

We make our own compost tea and use it as a spray on our flower farm. The main function of the compost tea is to act as an inoculant and to add beneficial bacteria and fungi to the surfaces of the plants’ leaves, stems and on the surface of the soil.

We spray our compost tea after spreading compost out on our newly prepped beds. We spray the compost tea onto wet beds before planting, so the microbes can work their way down into the beds and help break up compaction. It is important to spray compost tea on an overcast day, or when the sun is starting to set.

We also root drench our “needier” plants (roses, blackberries, squash, fruit trees) by watering them with 1 cup of compost tea mixed into 2 gallons of water, per plant, with a watering can once every two weeks or whenever they seem to need a boost.

How to make Compost Tea for the Flower Farm

Use old pantyhose and fill with 2 cups of good compost. Tie in a knot. Hang the pantyhose from the side of a 5-gallon bucket filled with water (use filtered water, or you can leave the water out in the sun for a day to naturally evaporate the chlorine in it). Add a fish tank bubbler to the bucket (aerating the water accelerates the microbe growth). We also add 2 tbsp each of: liquid humate, liquid fish emulsion and unsulfured blackstrap molasses. After a few days, strain the tea with a fine mesh sieve into a garden sprayer and spray the garden down with it!

Alfalfa Pellets during soil prep

Alfalfa meal is a soil amendment we always use when prepping beds in the spring. I discovered huge bags of pelleted alfalfa that are sold as horse food for much, much cheaper than any alfalfa meal sold anywhere. We plant all of our perennials with a handful of alfalfa pellets in the planting hole, and every annual bed gets a sprinkling of pellets on it (we add alfalfa everywhere except on the dahlia beds). Alfalfa pellets add organic matter to the soil for earthworms and soil microbiology to break down.

What exactly are alfalfa pellets? Alfalfa, sometimes called “Timothy,” is a grass that is grown as a cover crop or for animal forage. It is known as a dynamic accumulator, which means it has a very long taproot that mines minerals deep within the earth. When the grass is mown down and pelletized (for horse/rabbit food), all of those nutrients from deep within the earth are available in the leftover dried plant matter. When added to the garden and processed by soil microbes, the nutrients are then available for the plants.

Leaf Mulch as a soil amendment

I consider leaf mulch a soil amendment, and not simply just a mulch, on our flower farm. We use it at the end of every year to mulch the annual beds and keep them nice and protected over the winter. Throughout the winter months, earthworms and soil microbes very slowly start to break down the leaf mulch to turn this plant waste into glorious nutrients and minerals for the plants for the upcoming season.

The leaves stay in place indefinitely because in the spring, we simply cover the leaves up with 1-2 inches of fresh compost and either use a compost fork or a broadfork to gently work it in. What results is a gorgeous, fluffy bed that has less weed pressure, holds in more soil moisture, and has tons of food for microbes to feed on.