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Have you ever scattered perennial herb seeds around your garden, only to never have them sprout?
Or maybe even stranger, they DID grow - but not until ONE YEAR later?
When I began gardening, I was excited to grow my own herbs so I could save some money. I bought a bunch of herb seed packets. Nettles, mullein, wood betony, mints, lavender, rosemary - you name it, I bought it.
Like a sweet summer child, I planted these seeds in the garden and in trays like they were broccoli or something. I got lucky with a few. Basil, oregano, and borage were thriving. But most other plants were a no-go.
I thought I must suck at gardening if I couldn’t get mint to grow. What was going on?
Eventually, I researched this seed situation, and it was like a lightbulb went on. And the light was shining in just the right wavelength (You’ll get that reference later).
It turns out, each seed goes through a personalized checklist of requirements before waking up from dormancy. Not knowing the requirements for certain plants is one of the most common mistakes people (like me) make when starting out with gardening.
Some seeds are pretty easy. Stick peas in a damp paper towel and they’ll germinate in a couple of days without much fuss.
Others are a bit more particular.
I realized there’s actually a LOT of intricacies hidden in different seeds, which evolved over time so they have a fighting chance at achieving their goal: World Domination.
Well, maybe not world domination. But at least some habitat expansion.
In this article, I’ll explain what I’ve learned about the processes, cues, and safeguards that seeds have in place. When you understand these nuances, you’ll be able to wake a wide range of seeds up with ease. The trick is to understand their needs so that they don’t want to reach for the snooze button.
Inside every seed is a tiny plant embryo that needs specific conditions to grow—like a botanical Goldilocks.
For survival, it waits for the signal to sprout when right balance of hormones, moisture, temperatures, and nutrients are present. Each one has unique requirements. Let’s look at some in detail.
What it is: Seeds that want to be surface sown need sunlight to start growing.
Similar to your phone’s camera, they can sense light quality and adjust accordingly. Instead of software algorithms, these seeds have what’s called a phytochrome system that helps them detect the quality and quantity of light.
Why they do it: These specialized plants only sprout when there’s no direct competition hovering over them.
If their light is blocked, that’s their signal that the timing isn’t right. Less competition gives these plants a better chance of survival. A study from 2000 found that usually, small seeds have a light requirement, whereas large ones are more likely to prefer the dark.
Examples: Alyssum and Sage
Get a Full Light-Sensitive Plant List Here
What it is: Some seeds are like a goth kid from the ‘90s - they prefer the darkness. While they can grow in the light, usually they perform best when they get their start nestled into the soil.
Why they do it: Like standard batteries, seeds have a limited supply of nutrients and energy stored inside them. Darkness helps them to be frugal with resources.
In the dark, the seeds can grow efficiently without triggering photosynthesis too soon.
Plus, being buried in the soil offers other benefits - when covered, they have better access to moisture and protection from extreme temperatures.
Example: Beans and Tomatoes can both germinate in light, but they’ll break dormancy at better rates in darkness.
(More interesting studies on this here and here)
What it is: Some seeds are like those people who need a cold plunge to get going in the morning. A period of cold, known as stratification, wakes them up from slumber.
It’s common for perennial plants to need cold stratification — I recommend double checking for this requirement when sowing any perennial seed.
Why they do it: This adaptation keeps them from sprouting during a random warm spell in the autumn. Instead, they wait for the cold of winter and then the the warmth of spring, which is consistently warm and friendly for young plants.
Examples: Wood Betony, Nettles, Echinacea
Here’s a detailed list of garden plants that need to be cold stratified
What it is: In fire-prone ecosystems, some seeds have developed a unique relationship with fire.
Like tiny smoke detectors, the airborne chemicals from smoke or charred wood alerts them to activate growth.
Receptors in these seeds are sensitive to chemical compounds present in smoke, like karrikins. When they sense these air-borne chemicals, germination is activated.
Why they do it: This adaptation prompts them to sprout only after a fire — competition is low, light availability is high, and nutrients are plentiful in the ash. It’s the perfect habitat for a young plant to thrive.
Examples: French Lavender (Lavandula stoechas) doubles its germination rate and reduces sprouting time significantly with smoke treatment.
What it is: Some seeds as having tough outer coats, like wearing armor to protect themselves from premature germination.
One way they can break through the armor is to go on an adventure - they actually need to pass through an animal's digestive system to grow.
In regions where fire is part of the natural cycle, some seeds need heat to break dormancy.
Why they do it: These hard coats evolved to keep seeds prime until conditions are right. Scarification is their way of getting a little help—whether through animal digestion or weathering—to weaken that armor so water can finally get in to kickstart germination.
The requirement for being eaten serves two purposes: it helps with seed dispersal (getting far away from home) and gives them some natural fertilizer for a growth jumpstart.
With heat, after a fire there’s way less competition for resources and plenty of nutrients in the ash. This means they can establish themselves quickly in a freshly cleared area.
Examples: French Lavender (Lavanduula stoechas) improves germination after experiencing a temperature of 248F (120C) for five minutes. Wild rose waits for the stomach acid treatment to sprout.
Get a detailed how-to guide on seed scarification technique (no birds required)
Each tiny seed holds a world of potential. Just like you, they can navigate cues and challenges to thrive and transform their surroundings.
With an understanding and respect for these old-as-time processes you get to actively enrich your ecosystem with more plant varieties. Knowing the why behind a seed’s peculiarities helps us to support the adaptations of nature.
So, plant with curiosity, tend with care, and watch your backyard come to life.
