Seed starting notes

Here’s some of the notes and links from the class I taught Thursday night, straight out of Keynote so very point form! Feel free to contact me with any more questions and thanks for a fun discussion.

Terms you might see:

F1 hybrid: a cross of two strains of the same species; reliable cultivars bred for particular traits. don’t save seed from these plants as offspring is unpredictable.

Open pollinated/ heritage: older, long-grown varieties. More genetic diversity, seed can be saved with more consistent results.

Organic: seed produced without the assistance of chemicals.

Graded seed: seed pre-sized for you for consistency, esp. For machine planting.

Pvp: protected, pantened seed. Do not reproduce this seed for sale. 

Annual: completes life cycle in one season.

Perennial: revives season after season.

Biennial: completes life cycle in two seasons.

Determinate: grows to a certain size, sets fruit, dies. Most fruit ripens at the same time.

Indeterminate: continues to set fruit until killed by frost. Vining, ever bearing, day neutral…

Pelleted: small seed coated with inert material to make it easier to handle.

Primed: seeds that have been treated to encourage germination.


Biggest considerations: big enough for root growth (3″), meticulously clean, and have drainage. Newspaper, Coffee cups, egg cartons (paper or foam, but a little small), yogurt cups, toilet rolls, compressed soil, take out containers, salad clamshells, milk cartons, etc etc.

Drainage Trays: buy plastic ones, or use foam grocery trays, or cardboard.

Planting medium:

Look for seed starting mix, seed and cutting mix, potting mix, etc. not topsoil. Needs mor nutrients.  Don’t use regular garden soil. Too heavy generally, cracks easily, weeds and disease.You can use it as a base but be warned.

Possible add ins: compost (screened), vermiculite, coir, slow release fertilizers (not rock minerals).

Plant by-product mediums: coir is coconut husk, rice husks. Can dry out quicker.

Canadian gardening website on gelatin seed starting.

Prepping seeds:

Scarification: Nicking the seed coat with a razor blade or nail clippers, abrading it with sandpaper, pricking it with a needle. Don’t go so deep as to damage the embryo.

 Stratifying seeds: Exposing the seeds to a period of cold temperatures to simulate winter.

Moist stratification:  put seeds in a plastic bag with an equal amount of damp sawdust or sand. Set the bag in a warm spot for a couple of days to allow the seeds to absorb water, then put it in the fridge. Length of time depends on seed.

Soaking seeds in warm water for at least 24 hours softens the seed husk, removes germination inhibitors. Seeds such as beets, carrots, parsley and spinach. Legumes too.

Pre-sprouting seeds–hastens germination, eliminates waste and thinning, saves space, etc.

Use paper towel or a large paper coffee filter, get itwet but not dripping.

Sprinkle seeds evenly over half the towel, then fold over a couple times, pressing seeds lightly into towel, and tuck in plastic sandwich bag. Leave it open and set in a warm spot. 

Check seeds daily and make sure the towel stays moist.

When you see the radicle–first little growing tip–pick up the seeds gently(a knife blade can be helpful) and plant as you normally would, containers, outdoors, etc. be extremely careful not to break the root or it will die. 

***Many seeds won’t need any treatment! others need a combination of treatments, Every seed has its preferred means of germination so do some homework to make sure you’re matching your method correctly. has details on growing and harvesting almost any imaginable plant.

Factors for success:

Moisture: wet down mix first. Water from bottom to avoid floating seeds. Or spray bottle. Cover to retain moisture.

Planting depth: generally you will plant the seed as deep as it is long. Some require light so they are surface sown, on loose soil. Tiny seed techniques.

Light: lots of sun, keep it indirect to avoid overheating. Some seeds need dark to germinate: tomatoes. Green houses with diffused light, grow lights, not just regular tube lights.

Temperature: soil needs to be warm but too much heat can kill seeds. Heat mats, soil thermometers. Plant by natural cues– lilacs begins to leaf out, soil about 10 degrees. Carrots, beets, chard. When it blooms, beans and things. When the blooms fade, more tender stuff.


Avoiding disease: keeping moisture levels adequate but not too high to avoid damping off. Use fan to keep air circulation up, also helps hardening off. Beware of too much heat/direct sun burning small sprouts. 

Potting up: depending on size of original containers and how long before they can go in the ground. Allows adequate space for root development. 

Hardening off: gradual exposing plants to normal outdoor conditions to avoid transplant shock. Short periods, out of direct sun and wind, over several days increase time and elements.

Starter chart of what to plant when. Note that many things benefit from being direct seeded. Early starts are to ensure adequate growth time for proper harvest.

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