Aeroponic Vegetable Growing, Part One

How to Produce Abundant Veggies with an Aeroponic Growing System

Aeroponic vegetable growing is becoming increasingly popular in both commercial crop production and home gardening. And it’s easy to see why! Aeroponic growing systems can produce high-yield harvests of excellent-quality crops using a fraction of the water and fertilizer compared to traditional farming methods.

Above: A beautiful head of mature aeroponic broccoli that was transplanted into a winter greenhouse as a small seedling.

The Advantages of Aeroponics

Aeroponic systems are virtually “medium-less,” meaning there’s no soil or growth substrate required. This offers significant savings in ongoing expenses and can help reduce the environmental footprint of crop production. A small starter plug is all that’s needed to propagate crops from seed in aeroponic vegetable growing. For plants propagated from mother plants or rooted as clones, no growth medium is necessary at all.

These systems are automated for fertigation, meaning a timed misting cycle nourishes the roots while keeping plants supported above. This results in faster, more even plant development as the roots receive the optimal balance of water, oxygen, and minerals, with nothing blocking their absorption.

One of the key benefits of aeroponic vegetable growing is that plants grown in this way tend to be exceptionally clean and hygienic. With no soil to harbor pests or pathogens, your harvests remain free from contamination.

Additionally, because plants have more access to air around their roots, they grow faster and healthier, taking up nutrients and water more efficiently than they would in a traditional growing medium.

Real-Life Example of Aeroponic Vegetable Growing

In a real-world example, we grew kale, broccoli, and brussel sprouts in a winter greenhouse using aeroponics—ideal vegetables for colder climates. Here’s what we learned about the process.

Aeroponic Growing and Water Quality

Water quality is a key factor in aeroponic or hydroponic growing. It’s essential to use water that is free from biological contaminants and low in dissolved solids. Well water, even with significant filtration, can still pose challenges, as any microbial activity can quickly overwhelm the aeroponic system.

If you’re unsure about the quality of your water, consider using a water analysis service to test for contaminants. Filtered tap water is typically best suited for aeroponic systems. In this example, we used tap water with around 300 PPM (parts per million) of dissolved solids and a pH of about 7.5, with no noticeable biological activity. A sediment and carbon filter purified the water before it was added to the aeroponic reservoir.

Propagating Vegetable Crops with Aeroponics

Aeroponic vegetable propagation is straightforward and yields excellent results, especially if you follow some basic protocols. Even if you don’t plan to grow vegetables to maturity in the system, it’s an ideal method for starting plants with high consistency and health.

Organic propagation plugs made for aeroponic systems are great for starting seeds. Simply plant the seeds in the plugs and place them in the system. Automated misting cycles will take care of the rest. A 20-30 second “On” time at 4-minute intervals works well to keep propagation plugs and seeds hydrated.

The burst of air from each misting cycle stimulates rapid seed germination and growth. Just be sure to maintain the water pH between 5.8 and 6.4, and wait until seedlings develop true leaves before adding hydroponic fertilizer and following a crop feeding schedule.

In our aeroponic vegetable growing example, seeds for broccoli, kale, and brussel sprouts germinated about 25% faster than expected.

Establishing Aeroponic Vegetable Seedlings

Unlike potted plants or traditional trays, aeroponic vegetable seedlings can stay in the system for longer periods before needing to be transplanted. Most of the early plant development occurs in the root system, so there’s little concern about becoming root-bound in aeroponics.

Above: This aeroponic vegetable seedling remained in the propagation system for an extended period.

As the misting cycle is automated and there’s no growth medium to trap the roots, every plant receives identical root zone conditions, ensuring even development. Plants remain strong and vigorous for weeks before needing to be transplanted.

Aeroponic systems are also a great tool for field vegetable growers who want consistent, vigorous transplants for their crops.

Aeroponic Vegetable Seedling Grow Tips:

1. As plants start to increase in mass, gentle air circulation will help keep growth sturdy.  Excessive humidity levels and  warm temperatures tend to make plants stretch, especially when air circulation is not adequate.
2. Hydroponic fertilizer concentrations can be increased to 500 PPM above the source water TDS once seedlings are well established with a few sets of leaves and a healthy root system.
3. Light levels should be increased moderately, to around 250-350 uMols if using a light meter. If using full spectrum LED lighting strips, this can be as easy as turning on or adding additional strips of lights.
4. About two strips of lights over a 2’ X 4’ aeroponic module is plenty for germination, then increasing to four and eventually six Full Spectrum LED strips as plants become well established.

Transplanting Aeroponic Seedlings

After about 2 to 3 weeks, seedlings are ready for transplanting into wider production spacing. Note that aeroponic seedlings can be “parked” in their propagation setting for at least double that time and remain healthy and vigrous, if needed.

Aeroponic vegetable growing makes transplanting quick and efficient. For example, some seedlings were transplanted directly into eight-site aeroponic module lids (2′ x 4′ area), while others were placed into 3.5-inch net pots using a neoprene collar to block light and keep moisture in.

In aeroponics, there’s little risk of transplant shock. Transplants continue developing seamlessly when placed into their new, more intensive growing conditions.

In our next instalment we’ll talk about ramping up the conditions in the growing environment and further dialling in the aeroponic fertigation regimen. Plus plenty more!