Busting 6 Seed Starting Myths

Amidst all the well-meaning guidance, many myths about seedling care have taken root, leaving gardeners to wonder what’s truth and what’s fiction. It’s time to shed light on these misconceptions and set the record straight.

Myth 1 - You Need Seed Starting Compost

One common myth, which garden centres often promote (I wonder why!), is that seed-starting compost is necessary. The simple answer is: no - it isnt.

I sow seeds in the greenhouse using whatever bag of multi-purpose compost I have lying around—and you know what? It works just fine.

Many believe that compost, being nutrient-rich, might overwhelm tender seedlings, leading to poor development. I have never found this to be true. In fact, it works the other way for me and saves me a job in repotting my seedlings soon after sowing. Indeed, if you do use seed compost, then this is something you will quickly have to do before they yellow and die!

Myth 2 - Seedlings Dont Need Nutrients

One of the most persistent myths about starting plants from seeds is that seedlings don't need nutrients. It's common to hear gardeners say that as long as seedlings are provided with water, light, and warmth, they're all set for growth.

This misconception stems from the fact that seeds indeed contain a tiny store of nutrients sufficient to germinate and push forth the first sprouts. However, as these initial reserves deplete, the emerging seedlings quickly find themselves in need of external nutrients to continue their growth.

That's not to say that you should pump them full of plant food straight off the bat, but a nuanced approach works best. As I mentioned in Myth One, I love to use multi-purpose compost for my seeds. You get them off to a good start and don't have to re-pot them quite so quickly, but importantly, you also don't overdo the feeding!

Myth 3 - You Should Only Plant One Seed Per Module

When planting seedlings, one should strictly plant one seed per module. At first glance, this seems logical. It promises a neat organised start to your garden, with each seed having its own designated space to grow without competition. But this isn't always the best option, so lets take a look.

Firstly, not all seeds have the same germination rate. Some varieties, particularly heirlooms or those that haven’t been genetically enhanced for uniformity, can exhibit a wide range of germination successes.

By planting multiple seeds per module, you can hedge your bets against seeds that fail to germinate. After the seeds sprout, the weakest seedlings can be thinned out, leaving the strongest to continue growing.

Additionally, certain types of plants actually benefit from being sown in pairs or small groups. For example, peas and beans are known to thrive when planted closely because they can support each other as they grow. This not only simulates natural growth patterns but also can lead to stronger, healthier plants.

Then, you also have many crops that will happily grow side by side but might not develop fully when you are done so. Onions are one great example of this, you can multi sow many onion seeds per module and grow them on like this for their entire life. They will be perfectly happy, and you will end up with more onions in total, but each one will be smaller. These are some of the pros and cons you will need to weigh up yourself.

Myth 4 - You need full spectrum grow lights to start seeds indoors.

The myth circles the idea that in order to mimic the sun's broad range of light, one must invest in expensive lighting solutions. However, this isn't entirely true and might lead to unnecessary expenses that could be avoided.

Firstly, it's crucial to understand what "full spectrum" means in the context of grow lights. These lights are designed to cover the entire spectrum of light emitted by the sun, including wavelengths not typically necessary for plant growth. While it's true that plants use a wide range of light for photosynthesis, the most crucial wavelengths fall within the blue and red spectrums. These are adequately provided by far less expensive lighting solutions than what's often marketed as "full spectrum."

The truth is, pretty much any light will work well for seed starting. So look at the lumens - and the wattage for power costing and then make your decision. I recently bought a regular old LED strip light and it works perfectly well for my peppers!

Myth 5 - All seeds need heat to germinate

It's a widely held belief that all seeds require warmth to kickstart the germination process. This myth, however, doesn’t hold up under scrutiny. While it's true that a majority of common vegetable seeds thrive in warm conditions for germination, this isn't a universal rule applicable to all seeds. Different species have evolved unique germination triggers based on their native climates and ecosystems.

For instance, many seeds will germinate just fine in cooler temperatures, and some even require a period of cold to break dormancy—a process known as stratification.

Some seed's germination rate slows down as the weather gets hotter. This is common with cold weather crops - and when you think about their natural growing habits, it makes a lot of sense. Broad beans, spinach, and parsnips are just a few vegetables that actually do better when the soil temp is below 15 celsius.

Myth 6 - Seed Starting Soil Needs To Be Sterile

This myth is rooted in a misunderstanding of soil biology and the needs of developing plants.

In reality, the expectation that this soil is or needs to be completely sterile is misguided. Some packaged soils are indeed heat-treated as a measure to reduce the presence of pathogens. However, even these so-called "sterile" soils aren't completely devoid of microbial life. It's important to recognize that a completely sterile environment isn't necessary for seed starting.

The most common threat to seedlings isn't the soil's sterility but rather a condition known as damping off. Damping off is caused by a variety of fungal pathogens that exist in the air and can even be found on garden tools or the gardener's hands. These pathogens are adept at finding plant material to infect, regardless of the soil's sterility. Thus, the focus should shift from striving for sterility to implementing good sanitation practices and proper care to prevent disease.

One advantage to sterile soil - when growing indoors - is the absence of fungus gnats. The eggs of fungus gnats can be found in many normal composts, but in sterile ones, they will have been killed off.