A BRIX Boost "Recipe"

If you’ve been following along our BRIX post series, you know that high BRIX levels come from healthy soil, happy microbes, and efficient photosynthesis.

Consistent, long-term high BRIX levels happen when we support the soil and microbes over time. But while we’re working toward that, we can help our dahlias along with a temporary BRIX boost foliar spray / soil drench.

A Foliar Spray for Temporary BRIX Boosts

This past season on our farm, we experimented with an all-natural foliar spray focused on making sure there was plenty of micronutrients and sugar for the microbes and therefore, our dahlias.

Our spray included humic acid, fulvic acid, kelp meal, fish emulsion, and unsulfured blackstrap molasses. We didn't just pick these ingredients willy nilly. From our understanding:

• Humic acid helps unlock nutrients in the soil

• Fulvic acid helps carry nutrients into plant cells

• Kelp meal encourages stronger, healthier leaves and roots and is packed with micronutrients

• Fish Emulsion is an organic nitrogen source with trace minerals that helps with leaf growth

• Unsulfured Blackstrap Molasses is microbe candy, or quick energy for microbes, also with trace minerals

I am certainly not the only one doing this and I didn't make this concoction of ingredients up on a whim. I checked the ingredient lists of other products on the market—including Warren Vigor's Vigor Plant Booster that people rave about—and then sourced my own concentrates of those ingredients from my fancy farm store, Amazon.

There are other products on the market that have a similar ingredient list but may be missing one or two of them. One of them is Nature's Way Soil Liquid Humic & Fulvic Acid Concentrate. It seems to be easier to get your hands on than the Vigor Plant Booster (which is sometimes out of stock) but it's missing unsulfured blackstrap molasses so to those who use this one on their dahlias (like my parents), I recommend purchasing a molasses concentrate to add to the mix.

An early-season photo of our dahlia field.

Our Farm’s BRIX Boost “Recipe”

Here's the "recipe" we used last season! Please note that we calculated these amounts per gallon of water by reading the label on each product. So depending on what product you find, please please follow the application rate on the product you purchase.

• 2 Tbsp. unsulfured blackstrap molasses

• 1/4 cup liquid humic and fulvic acid combo (I can't find the one I used to use. This one looks like it has both)

• 1/4 cup liquid kelp

• 2 Tbsp. fish emulsion (stop using once buds start forming)

We applied this every two - three weeks last season, and plan to follow a similar schedule this season.

The Results

As I mentioned in a previous blog post, the results of us using this spray along with the other love we were showing our soil microbes were promising: dark green thick leaves, fewer leaf-chewing pests (idiot grasshoppers were around and even on our dahlias but largely left them alone), and rare leaf chlorosis. The BRIX measurements we took at the beginning of the season were 7's. By mid to late season, our BRIX measurements were consistently in the 9's though we got a handful of readings in the 10's. Since we do other things to care for our soil microbes (in-season straw mulch, dried molasses at planting, leaf mulch in off-season, avoid tilling and synthetic fertilizers, etc.)...I don't know how much of a jump this spray alone contributed to our dahlia BRIX level rise. I do know, that when my parents started using these ingredients on their dahlias, the results were noticable enough that everytime my dad would see me he'd say, "they REALLY like that stuff!" He grew up farming more conventionally so at the time, he wasn't using or doing anything else to his dahlias or soil other than spraying them with the "recipe" above (which took a little convincing but he did it). So, we're gonna keep at it!

Because what we saw on our farm was so encouraging, I've continued digging into others' research in the off season. This podcast and this article are AMAZING reads / listens if you haven't done that yet.

What I’ve learned is that while our dahlias clearly responded well to us spraying these micronutrients on their leaves, applying them directly to the soil instead may offer greater long-term benefits.

Why I'm Moving Towards a Soil Drench Instead

This article put out by the folks at Washington State University was helpful in explaining that foliar feeding works best for delivering micronutrients (not macronutrients like nitrogen, phosphorous and potassium) when soil pH that is either too acidic or too alkaline keeps nutrients locked up so plants can't use them. The spray ingredients we used last season contain mostly micronutrients, so no problems there. Spraying nutrients directly on the leaves themselves is super helpful when your plants need a quick, temporary boost to help them through stressful moments. But...I've learned that foliar feeding has its drawbacks—it doesn't last long, the nutrients don't go down into the roots and the leaves can only take in so much at a time. So in most cases, soil drenches tend to be the better choice.

When nutrients are applied directly to the soil, roots take them up with the help of soil microbes. This not only feeds the plant but also nourishes the soil life, building long-term fertility. Soil drenches may take a little longer to show results, but over time they encourage healthier soil and more stable BRIX levels. We're going to lean heavily on the soil drench method over foliar feeding this upcoming dahlia season and report back! Our next blog post in this series dives into why plants with higher BRIX values have less pest pressure.