Everything you need to know about the germination of aromatic plants

Let there be light

Hey there, symbiotes!

Today, let’s dive into a hot topic amongst microgreens growers: aromatic plants. Whether you’re using them to flavor your dishes, infuse your teas, or add a touch of green to your kitchen, they’re an absolute must-have for any home-growing enthusiast. But did you know that some varieties of aromatic plants can be a bit... temperamental when it comes to germination? That’s right! Unlike most plants, certain aromatics need light to kickstart their growth. And trust me, if you don’t know this, your seeds might sulk in their soil and refuse to sprout.

Why Is Light Crucial for Some Aromatics?

Most seeds germinate in the dark, safely buried in the soil. That’s because their initial growth relies on internal reserves that allow them to break through the soil surface before seeking light for photosynthesis. However, for some aromatic species like agastache, shiso, and lemon balm, germination is stimulated by light. Why is that?

These seeds are called photosensitive: they need to perceive a certain level of light to activate their germination process. It’s as if they’re waiting for a little light signal saying, “Alright, it’s safe to come out; the sun is here!” This clever evolutionary strategy ensures they grow in favorable conditions. Burying them too deeply in the soil essentially condemns them to stay dormant.

How to Successfully Germinate These Temperamental Seeds

Don’t worry; I’ve got some pro tips for you:

  1. Sow on the surface: Unlike your microgreens, which love a fine layer of soil to keep moisture in, photosensitive aromatic seeds should be placed on top of the substrate. You can gently press them down for good contact with the soil, but don’t bury them!
  2. Provide a good light source: Place your seeds in a bright spot, but avoid direct sunlight that might dry them out. A well-oriented window or a LED grow light works perfectly.
  3. Maintain moisture: Seeds on the surface can dry out quickly. Use a spray bottle to keep the soil moist without drowning it. Alternatively—and I highly recommend this—use a thin transparent sheet of glass or PVC to cover the seed tray. This keeps moisture close to the seeds while still allowing light to pass through.
  4. Be patient: Some aromatic seeds take much longer to germinate than other species. If nothing happens after a few days, don’t panic. They’ll eventually poke through the surface. 😊

Examples of Aromatics That Need Light

Here are a few aromatic plants that clearly require light for germination:

  • Agastache: Its sweet, anise-like flavor is a game-changer.
  • Shiso (purple/green): Exotic aromas of cumin (purple shiso) and mint (green shiso).
  • Lemon balm: The European lemon balm, celebrated since antiquity for its calming and aromatic properties.

Our Experience at Symbiose: A Little Anecdote

At Symbiose, we’ve had our fair share of failures with aromatic seed germination. Back in the early days, we couldn’t figure out why nothing sprouted while our other microgreens thrived effortlessly. Was it the seeds? The soil? The temperature? None of the above. The problem was our method.

By placing aromatic seeds with others in the dark, we were depriving them of the light so crucial to their germination. These days, we use a system of transparent covers and low-energy lamps with timers designed specifically for our aromatics. This setup delivers excellent results. That said, nothing beats daily attention, cleanliness, and meticulous care. Aromatics remain the most delicate varieties to grow. 😉

Conclusion

Growing your own aromatic plants is pure joy: they’re fresh, fragrant, and add a homemade touch to your dishes that always stands out. But for certain varieties, remember: let there be light! Sowing on the surface, gentle watering, and a good dose of patience and diligence are the keys to success.

See you soon, and happy growing to all!

Aristide