Get a Jump on Your Gardening Season: Indoor Seed-Starting Tips

posted in: Seeds, Starts | 1

By Arzeena Hamir, MSc

If rain, sleet, or even snow is keeping you out of your garden but you are itching to get your hands in some soil and see green things growing, now is the perfect time to raise seedlings indoors. You can do it without a greenhouse!

By starting from seed, gardeners will not only be able to get a jump on the season, but also grow many heat-loving plants that cannot be directly seeded outside.

Top 3 Reasons for Starting Your Own “Starts”
But why bother starting from seed when nurseries and garden centers are full of seedlings later in the spring?

Here’s why:

  1. Value.
    A packet of seeds costs about the equivalent of buying one seedling! You’ll get 20-30 times more seedlings when you start your own from a packet of seeds.
  2. Variety.
    The varieties available in seedling starts are often limited. Growing from seed gives gardeners access to hundreds of varieties, some only available at the local level. Ever heard of the “Merville Rocket” tomato? It’s only available through Good Earth Seed in Black Creek.
  3. Productivity.
    Many early flowers and heat loving vegetables including tomatoes, peppers and eggplants need to be grown from seed indoors because they require so much heat to germinate and have a long growing season. Starting them indoors allows growers to have good temperature control and vastly increases the germination percentage.

Germination Equipment: Keeping it Simple
So what’s needed to grow seedlings indoors? Let’s keep it simple, yet effective. For the first part of indoor seed-starting, germination, you only need 5 things:

  1. Containers
  2. A medium that will hold moisture
  3. A source of heat
  4. Labels
  5. Seeds – follow indoor planting instructions on seed packets

About Containers
Fortunately, seeds aren’t picky about the type of container and it doesn’t have to be a specialized seed-starting tray (although they are available).

The container itself just needs to be able to:

  • Keep its form
  • Provide structure for the seedling

Most households have a variety of containers on hand which can be easily re-purposed for starting seeds. These include:

  • Yogurt containers
  • Salad boxes (“clamshells”)
  • Milk cartons

Plastic, especially a container with a lid, has the added benefit of holding moisture in, which is critical for the first stage of germination.

All that is required to re-purpose a plastic container is to poke drainage holes in the bottom to allow excess water to drain.

Note: Although paper and cardboard products can be used, they do not hold their shape for long and tend to evaporate water very quickly.

Seedlings growing in a re-purposed “clamshell” plastic container.

About the Medium
The medium that holds moisture can be anything including:

  • Moist paper towel – Although seeds sprout readily in paper towel, an extra step is required to transplant them into another container to enable them to grow.
  • Peat-based seed starting mix – This is what most gardeners use.

What’s in Starting Mix?
Most seed starting mix is a mixture of one or several of the following ingredients:

  • Peat – the finer the grind, the easier it is to work with
  • Coconut coir – the finer the grind, the easier it is to work with
  • Perlite (a puffed clay)
  • Vermiculite (another type of puffed clay)

Why not just dig up some soil or compost from the garden and use it? Here’s why:

  1. Soil is very heavy and does not take kindly to the wet/dry cycles that seedlings need to go through; it tends to harden and crack in those circumstances.
  2. Soil can bring with it some unintended stuff including:
  • weed seeds
  • fungi
  • bacteria
  • slugs & sow bugs (that love to eat your little seedlings)

For these reasons, gardeners often choose a “soil-less mix” in order to maintain a more sterile environment during seed-starting.

About Your Heat Source
A dependable source of bottom heat (set to about 70F) makes seed-starting go so much faster. Commercial ventures often build sand boxes with buried heat cables to achieve the desired temperature.

But at home, an old fridge will give off heat from the top, as may a water heater.

Warning: heating blankets are far too warm and may cook young seedlings.

What About Light?
Notice that there is no mention of light or food yet. That’s because very few seeds require light to start germination and all seeds come with enough food for the seedling to produce its first set of seed leaves plus one true leaf.

What’s Next? Seeding & Labeling
Once all the equipment is assembled…

  1. Pre-moisten the seed starting medium with warm water
  2. Fill the container to the top with moist medium
  3. For large seeds, sprinkle or individually place the large seed so that there is enough room for each seedling to grow with space. Crowded seedlings are difficult to separate.
  4. Cover the seed with a depth of mix that is two times the diameter of the seed. Note: Large seed needs lots of moisture to begin germination so it needs mix all around it, to a large depth. Small seed needs less.
  5. Press the mix down so that the seed has really good contact with the moist medium. This step is critical!

Label Your Seed Starts!
Labels are critical. It’s often impossible to tell the type of seedling (Brandywine tomatoes versus Cherokee Purple) when they are young.

Make your own labels with:

  • Popsicle sticks
  • Cut up yogurt containers
  • Repurposed blinds

Use a wax pen or waterproof ink that won’t fade. Be sure to include all of the following info:

  • Type of plant
  • Variety
  • Date seed was sown
Label seedlings – no one enjoys “mystery” plants.

An Important Reminder About Moisture
If your container doesn’t come with a lid, a clear plastic bag will help hold the moisture in. Once your container is placed over a source of heat, check regularly that the mix doesn’t dry out. This is especially important for small seed that is close to the surface.

About Growing Seedlings
Most seeds germinate between 4-7 days. Here’s where labeling the date becomes important. Warmer temperatures will help speed up the process but if the seed isn’t up after two weeks, check to see if any sprouting is happening under the surface.

Once seedlings are above the soil, it is critical that:

  1. The lid/plastic bag covering the container is removed
  2. They are put under light
  3. The temperature comes down to 55-60F

Cooler temperatures ensure the seedlings grow slowly. Although it sounds counter-intuitive, a cool garage is an excellent place to grow seedlings (as long as the light system is set up and the garage doesn’t freeze).

Let There Be Light!
Light is essential to keep seedlings short. If they don’t detect UV light, they begin to stretch and become “leggy”. They’re then very difficult to work with and the process may need to start all over again.

On the West Coast, where days are short in late winter and the quality of light is very low, it is necessary to supplement light with an artificial source, at least until mid April.

Grow lights can be purchased but fluorescent bulbs can also be used, as long as the seedling is kept to within 4” of the bulb.

The lights can be connected to a timer so that they get about 14 hours of light per day (6am to 8pm).

Reminder: Do what’s necessary to keep seedlings close to their light source. Alternatively, hang the lights on chains to allow raising and lowering.

Seedlings elevated on juice cartons to be closer to the light source.

About Watering – Don’t Overdo it
Gardeners are notorious for being too kind to seedlings. Unlike the germination stage, seedlings actually need the surface of the soil to dry out in between watering.

If the surface is allowed to be damp all the time, it can encourage a fungus called damping off to grow. Use the weight of the container as a better gauge for the need to water. If gardeners are worried about damping off, sprinkle cinnamon, a natural fungicide, on the surface of the soil.

Seeded trays in the light of the living room

The Joy of Seeds

Growing your own starts from seed is a joy.  Once the basic equipment is on hand and a few simple steps are followed you’ll be on your way. Now is also the perfect time to attend local Seedy Saturday events, order seed catalogues, or visit garden centers for their seed collections. A whole new world of seed varieties is beckoning!

Arzeena Hamir is an organic farmer, agronomist and mother from Merville, BC. Arzeena and her husband own Amara Farm, a 26-acre certified organic vegetable and blueberry farm just north of Courtenay, BC.

Follow Arzeena on Facebook! https://www.facebook.com/arzeena

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