Feeding Vegetable and Flower Seedlings with AgroThrive

An article by Travis Key from Lazy Dog Farm

Advantages of Growing Your Own Plants

Growing your own vegetable and flower transplants, as opposed to buying them, provides lots of advantages to the backyard gardener. It allows you to have full control over the growing process and transplant them before they become root bound in their planting container. It also allows you to choose what varieties you want to grow as opposed to only being able to pick from the varieties that a store has chosen to carry.

Mastering seed starting and growing your own transplants is an extremely valuable skill to have as a backyard gardener. As spring approaches, we’ll have several blogs talking about the best practices for starting seeds and growing your own transplants. In this blog, I wanted to share a technique that we’ve been using over the last couple years that helps us grow some very healthy vegetable and flower transplants.

Using a Sterile Seed Starting Mix 

Let’s start by explaining what necessitates this “microdosing” technique that we’ll describe below. When planting seeds in a greenhouse or indoor seed starting room, it’s important to use a sterile seed starting mix. This ensures that no bacterial or fungal pathogens will infect your seedlings as they grow to transplanting size.

We prefer ProMix BX or Sunshine Mix #4, but there are lots of good sterile seed starting mixes on the market. Most quality mixes contain peat, vermiculite, and perlite as the base ingredients. Other ingredients will vary depending on the brand. These downside to these mixes being sterile is that they have no nutrients in them.

When to Start Feeding Seedlings

Seeds have sufficient energy inside them that allows them to sprout when they are watered in the ideal soil temperatures. But once that seedling starts forming roots and leaves, it will need additional nutrients. If you’re planting directly in the ground, it’s likely that your soil has some level of nutrients in it. But when using a sterile mix for seed starting, you’ll need to supplement with low dosage fertilizations.

Most sources recommend starting fertilization when seedlings form their second set of leaves, also known as “true leaves.” Prior to this stage, the seedling might not have developed enough roots for nutrient absorption. However, we have found that we can “charge” the seed starting mix earlier than the true leaf stage by using AgroThrive fertilizers.

Use Caution When Fertilizing Seedlings 

Because they’re small and tender, you must be careful when fertilizing them — especially if you’re using synthetic fertilizers. This is one of the many reasons we prefer to use AgroThrive on our seedlings. There’s little risk of burning the seedlings by adding too many nutrients at one time.

We’ve experimented with injecting AgroThrive through our greenhouse watering system on the day of planting and have had no issues with germination being inhibited. In fact, the plants seem to germinate very well and grow fast once they do. This was a game-changing discovery for us because it allowed us to start concentrating nutrients and good biology in our seed starting mixes, ensuring it’s already there when the plants need it.

Just make sure you mix at a low rate. We usually dissolve 4-6 ounces of AgroThrive General Purpose in a 5-gallon bucket, which is then injected through our watering wand at a 16:1 rate. This is low enough to not burn the plants or prevent germination, but significant enough to start building a nutrient base in the seedling trays.

“Microdosing” Throughout the Seedling Growth Cycle

With this system we are fertilizing every time we water at a very low rate. We call it “microdosing” because it gives the plants a small concentration of nutrients each day when they are watered. Since we started using this technique, our seedlings have developed stronger root systems and experience less transplant shock when planted in our raised bed or in-ground garden.

The biological components of AgroThrive fertilizers does much more than just providing nitrogen, phosphorous, and potassium. It promotes the presence of beneficial microbes in the seed starting mix and furthermore promotes healthy associations between plant roots and those microbes. This strong, healthy root system also makes the plant more resilient to drought or pathogens.

Can You Do This Too?

If you don’t have a fertilizer injection system for your greenhouse or seed starting room, you can still use this incredible “microdosing” technique. Simply mix 0.5-1 ounces of AgroThrive General Purpose fertilizer per gallon of water and apply it to your seedling trays with a watering wand or spray bottle. You can do this each time you water or water only with this low dose fertilizer mixture. Once you give it a try, I think you’ll be amazed at the results.

Thousands of gardeners have been tuning in to The Lazy Dog Farm YouTube channel where Travis covers a variety topics ranging from how to successfully start seedlings to how to make a flavorful hotsauce that packs a punch. Accompanied by his wife Brooklyn and their two boys, the gardens on their 2 acre homestead in southwest Georgia are always filled with a wide variety of vegetables that are enjoyed fresh or preserved for later.