SPRING into SPRING by Sowing Seeds Inside!

by Anja Lowrence, Master Gardener, SCMG.

Starting from seeds can be challenging, however following simple suggestions can make it a success!

WHAT YOU’LL NEED: Clean containers with drain holes, trays to hold containers & clear lids to hold in humidity, sterile potting soil or soilless mix, hydrogen peroxide, cinnamon, seeds, water, lights & a fan, patience.

  1. Clean containers with drain holes 

These can be purchased, or you can repurpose containers (single serving yogurt) from home. Just make sure that containers are clean, and you poke holes in the bottom for drainage.

2. Trays to hold containers & clear lids to hold in humidity

Seeding trays are inexpensive, or you can repurpose clear salad containers.

3. Sterile potting soil or soilless mix

Potting soil holds water well, however this also means that it does not always allow enough air to reach to roots & leads to ‘damping off’, a fungal infection. Potting soil can be lightened by the addition of perlite, which holds both air & water. Seed starting mix is ideal as it is ‘lighter’ however if seedlings are grown in this mix for longer than a few weeks, they start to struggle due to lack of nutrients, so add some diluted fish fertilizer of 10-10-10.

4. Hydrogen Peroxide

Hydrogen Peroxide can help reduce fungal infections as well as help oxygenate to soil while breaking down: 2 H2O2= 2 H2O + O2. Maximum concentration should be below 1% (1 T 3% H2O2per 2 c water). I use this when watering & in my spray bottles. It is light sensitive so use a dark container.

5. Cinnamon 

This acts as an anti-fungal agent. I add it to my potting mix before seeding/planting. Sprinkling on top of soil can help reduce damping off – so long as watering is also reduced.

6. Seeds

Your choice! No one disputes that garden grown tomatoes are the tastiest.

7. Water

Best to let water dechlorinate overnight. This also lets it come to room temperature prior to use. Always use room temperature water & water from the bottom. Do not leave standing water in the tray for more than an hour.

8. Lights & a Fan

They need to be intense. Most windows today have coatings that reduce the wavelengths of light entering. This may make using your windowsills problematic, so you may have to use grow lights. The fan is used to keep airflow over the seedlings to increase stem strength.

9. Patience

This is the hard one! 

Once you’ve collected everything, you may decide to pre-germinate your seeds using the ‘baggie-method’. For this you will need coffee filters & plastic bags. Place seeds on the pre-cut coffee filter, spray with water, fold coffee filter over, slip into the baggie & seal. Leave to baggie in a warm place, checking daily to see if any sprouting has occurred. Open the baggie regularly to ensure that there is air in there & that the seeds are not too wet. Once your seeds have sprouted you can pot them up, knowing that they have germinated.

To pot up your seedlings, fill containers to within 1 cm of the rim with damp potting soil, use a pencil to make a hole in the soil & carefully tease the rootlet down into the hole & gently press soil around plant. Be sure to hold seedlings by cotyledons & not the stem as the stem crushes easily. Place pots into planting tray & water from the bottom. Remove to a dry tray within an hour & place under lights. Remove any standing water from new tray ASAP.

If you choose to start in the traditional method, fill containers to within 10 mm of the rim with damp potting soil, plant 2-3 seeds per pot, cover with soil twice the smallest width of the seed. Some seeds need light to germinate, so don’t cover those, neither should you cover extremely small seeds. These can be sprayed with water to press them into the soil. Place pots into planting tray & water from the bottom. Remove to a dry tray within an hour & place under lights. Remove any standing water from new tray ASAP.

Your lights should start out about 3-5 cm above the containers & raised to maintain this distance during the entire indoor growing time. After plants have their first or second true leaves, a ¼ dilution of a 10-10-10 balanced fertilizer can be applied weekly. This is especially needed if seed starting mix was used.

About a week before your last frost date, plants can be brought outside to start hardening off. Leave the plants in deep shade when you start & slowly move them to increasing sun levels over a week or so. Should night temperature drop below 5 °C, cover or bring inside to prevent damage.

Transplant in evening or on an overcast day & water well. You don’t want to transplant on hot or sunny days as the transplants will suffer. Remember to water newly transplanted plants once a day for a week, once a week for a month & once a month until frost time. Transplants may wilt a bit at first, they may not need water, but rather shade. If you have been watering well, try shade first.

Things to keep in mind:

  • Biggest problem is overwatering & damping off. Keep a daily (or more) eye on your plants to prevent these, as well as making sure that they are receiving sufficient moisture (yes, you can go too much the other way!).
  • Do not pack your soil into your containers, it should be airy to allow roots to grow without drowning.
  • Do not leave containers in standing water – the roots will drown.
  • Do label your containers … we all say “I’ll remember” but we won’t!
  • Do harden off, both for sun & temperature. Sun scald kills leaves, weakening the plant.
  • Keep a daily journal with start dates, sprout date etc. for use as a reference next year.
  • Be patient, it takes a while for seeds to break dormancy, for seedling to mature into plants & for plants to set flowers, fruit & ripen.