Using seed science to improve your gardening yields

Starting plants from seed is a fairly easy task but a review of science behind seeds and of seed germination and growth will help to ensure success and may offer an answer to why those seeds didn’t germinate a few years ago. Follow the tips below when starting any plant from seed and you will get great results:

Seed Viability – do you have some seeds saved from a few years ago? There are a few ways of testing whether they will germinate. Pour the packet of seeds into a lukewarm glass of water. The seeds that sink to the bottom of the glass have a good chance of germinating. Those that float on the surface of the water are dead and should be discarded. Discard all of the floating seeds and then pour the water thorough a strainer to recover the viable seed. This seed can be planted when damp but if waiting a few days before planting, ensure that you dry the seed thoroughly before storing until needed in order to prevent mould.

Another method of determining seed viability is to perform a viability test by scattering about thirty seeds over a damp paper towel, top with another damp paper towel. Either place the towels in a tray, keeping the towels moist, or place in a zip-top plastic bag and seal. The towels should be moist at all times but not soaking wet. Use a mist spray bottle to keep moist. After a few days, check to see if the seeds, have sprouted. You can use the seeds that have germinated by planting directly into potting mix or the garden, by using tweezers to very gently handle these small sprouts.

Cozy Spot for Germinating Seeds – many seeds will germinate faster if the soil they are in is warmed from the bottom. Until the seedlings have grown upright and have the first signs of leaves place the tray in a warm spot.

  • The top of the fridge or the water heater is a great place for this. Just make sure you do not cut off the air circulation to the back of the fridge or around the fan on the water heater.
  • Some gardeners place a heating pad in the bottom of wooden tray (set to low for a few hours at a time) and then place the tray of seedlings on top.
  • With many homes having radiant floor heating today, the trays can get warmth from below when set right on the floor.

Stratification – some seeds need a dormant cold treatment before they will sprout. This process is called stratification. Check the instructions on your seed packet as the stratification period can vary from a few weeks to a few months.

For those that are only a few weeks you still have time to pop them in your freezer until spring thaw. Place the seed packets inside a plastic bag, seal and pop in the freezer until planting time. You may want to mark your calendar with a reminder so you don’t forget them. (Seeds that need stratification; bells of Ireland, bleeding heart, columbine, most evergreen trees, many shrub species, Cotoneaster, daylily, Euonymous, juniper, Hellebore, lavender, lupins, peony, phlox, Primula, trillium, Viola;

Scarification – some seeds have a very heavy, hard seed coat that needs to be penetrated before they can germinate. This process is called scarification. You can scarify large seeds by making a weak or thin spot in the seed coat, by nicking the seed coat gently with a knife or rubbing a spot with a nail file, emery board or fine sandpaper. Where you treat the seed will be where the sprout will break through the seed coat. For a less labour intensive treatment or a great way to treat small seeds soak the seeds for twenty-four hours in hot water at a 6:1 water to seed ratio).

Seeds that benefit from scarification are; apples, beets, beans, canna lily, carrots, celery, impatiens, lupins, morning glory, sweet peas, pansy, peas, parsley, fruit trees whose seed is a pit, trees or shrubs whose seed is a nut.

Starting plants from seeds for transplanting at a later date or sowing directly into your garden is a great way to save money. Following these tips will help to ensure that the plants that you sow from seed get off to the right start and you only have to do it once, which will keep you on budget and on transplanting schedule.