Seed Starting Tips: Giving Your Seeds a Good Start

It's hard to overstate how important getting a good start in life is. Of course, we all love saving a plant from a dire situation, but there is no mistaking that a good start leads to a great finish and when planting seeds, there are a few important details to remember.

Starting with quality seed is critical, always make sure your seed is viable before you are plant a whole flat or field. I like to check my seeds using a quick and easy germination test that I can do right on my kitchen counter. Wet and gently wring out a paper towel, lay it out flat and place about 10-20 seeds in a straight row on the paper towel, roll it up so the seeds are gently tucked inside the layers, and place the rolled towel inside of a ziplock or sealed container on your counter. In 2-3 days check your seeds to see what type of action has emerged. You should see swollen seeds and the first cracks as the sprouts begin to emerge. If your seeds are not viable it is likely you will see the beginnings of mold and mushy seed. This will give you a good idea of your germination rate and then you know how many seeds you need to plant per cell to get your ideal results. And don't worry, those seeds don't have to be wasted, you can gently move those little sprouts from the towel and into your soil mix as soon as their little sprout emerges.

Now that we know our seeds are viable, let's look at what type of soil/start medium is best for our little sprouts to get their best possible start. It's common for new gardeners to grab a bag of potting mix from the hardware store or garden soil from their garden beds or compost piles to use as a starting mix, but this is very often where things go wrong. Potting soil mix, garden soil and compost can contain a high amount of active biological ingredients that can rot seeds before they ever get a chance to set healthy roots. Starting your seeds in a sterile potting mix that is primarily peat moss (or coco coir) and vermiculite (or perlite) will give your seeds the best possible start for this delicate moment of germination and root set. Seeds need a light soil that is free from heavy loads of bacterial or fungal components. Potting mixes sold at the store are typically a minimum of 50% wood chips or forest floor ingredients that can cause havoc on sprouting seeds. These mixes can be used for stepping up starts into larger pots, but should be avoided when starting seeds. My go-to seed start medium is Pro-Mix, which is a mix of peat moss, coir and vermiculite inoculated with beneficial mycorrhizae that wakes up when the soil mix is wetted.

The next consideration is what type of pot to use - trays, cells, flats, cups, soil blocks - oh my there are a lot of options! I like to use soil blocks because the process uses very little start mix and my starts never get root-bound as the roots do a bit of self pruning as they hit the air spaces in between the blocks. However, they are time consuming to make and if you get your starts out of their cells on time you don't have to worry about root-bound plants. If you're interested in learning more about soil blocking, this is a great video for beginners. My advice is to start with what you have available and fill your trays, flats or cups gently, being certain that you don't pack or press the soil firmly into your cups. Developing roots benefit from moist and loose soil as they grow and take shape. As you water your starts, the water will slowly start to fill in the air gaps left in loosely filled pots.

When planting your seeds, it is important to know how deep to plant your seed. The rule of thumb is that to plant a seed three times the width of that same seed. For lettuce, tomatoes, peppers, and equally small seed that means you only want a scattering of soil to cover the seeds. Many small seeds actually need light to germinate! It is very important to cover your sprouting seeds with a small screen or tray that will keep birds and mice from eating your delicate sprouts as they emerge. Larger seeds, such as corn and beans, can be direct seeded into the ground, but must also be covered to protect from birds, slugs, and mice.

Knowing how much water to give your starts is a learned experience, and it takes time to figure out just what is needed in your particular environment. Depending upon whether your environment is hot and dry or cloudy and wet, you will need to water according to your environment and its needs. Ideally starts are kept under a clear cover, protected from rainfall and receiving full or partial sun, with morning light being preferred to afternoon sun. My rule of thumb is to water deep (but not soaking!) and allow the the upper surface of the soil to just start to dry out before watering again. Depending on the conditions, that could mean I have to water every day or maybe only once per week. Watering is a delicate balance, overwatering leads to bacterial or fungal issues that can cause rot and under-watering is a sure and quick death. The main thing is that you know how wet or dry your soil is - don't hesitate to put your finger deep into the soil to measure how well the water has penetrated!

Once your sprouts begin to grow and size up they will be ready for you to start feeding them nutrients. Begin feeding slowly, lightly as they develop and again before planting into your garden beds. Feeding your starts with light teas, such as kelp or worm casting tea, provides gentle and immediate nutrients and beneficial microbes, promoting resilient health and strong root development. Teas are easy to make, simply steep some kelp or worm castings in a bucket of non-chlorinated water for 12-24 hours, strain and drench plant leaves and soil. The risk of overfeeding is minimal and will greatly contribute to early and robust plant health!

Remember there is not one right way to grow a garden or start a seed! Dedication, observation, and patience, like everything else in life, will help you to learn what works best in your unique growing environment.

Best of luck and happy planting!

With aloha,

Michelle Carrillo

Hawai'i Seed Growers Network