Get Growing

Getting ready to start seeds? Here are the basics you need to know.

How to produce strong seedlings

Fill a flat tray with seed-starting mix, or make your own using sterilized, bagged planting soil mixed with equal parts perlite, vermiculite and sterilized coarse sand.
Fill the tray with the mix until it is level with the sides of the tray, then gently firm the mix down until it is 1/4" to 1/2" below the rim.
Place seeds evenly across the top of the flat, one to three seeds per cell, depending on the size and type of seed.
Cover the seeds lightly by sifting soil or mix over them. Some seeds do not need to be covered, just pressed into close contact with the soil.
Water the flat thoroughly using a seedling sprayer or watering can with a fine rose.
Label the tray and cover with a glass sheet, clear tray cover or plastic film to retain moisture and warmth.
Place the tray in a warm, bright spot but not in direct sunlight as it will cause the interior to heat up excessively.
Remove the glass, tray cover or plastic film when the plants emerge from the soil.
Move the flats into direct sunlight or under full-spectrum grow lights for best results.
Keep the soil evenly moist and maintain even airflow.
If required, thin out the seedlings, removing the weakest, smallest plants and leaving more space for the strongest plants to establish roots and grow.

The seedlings are ready to transplant when the first "true" leaves appear. Harden off young plants by slowly introducing them to the outdoors before planting them in larger containers, in the ground, or in a raised bed. Bring the seedlings outdoors for a few hours, gradually increasing their outdoor time for several days . This step allows the plants to develop thicker leaves and sturdy stems that will withstand the stronger light and wind. It also prevents transplant shock by gradually exposing the plants to outdoor temperatures.

Start Your Seeds

OSC Herb Seed Packets

OSC Flower Seed Packets

OSC Organic Vegetable Seed Packets

Fiber Pots

Self-Watering Seed Starter

Windowsill Seed Starter

Coir Pellets

Potmaker

Lee Valley Trowel

Seedling Sprayer

LED Grow-Light Kits

Starting Seedlings Early

Emma the Urban Botanist shows you how to get an early start on the growing season using one of our LED Grow-Light Kits and the Lee Valley Windowsill Seed Starter.

Seedling Heat Mats

Ideal for use with grow kits set up in cooler locations, such as an unheated basement or garage, or for providing supplemental heat at night for seedlings near a cold window.

Hardening off - Boot Camp for Seedlings

Before moving seedlings from the pampered pot, where they received just the right amount of light, nutrients and water, to the garden plot, they need a little toughening up.

Learn More

When is it time to sow outside?

When all danger of frost has passed
As soon as the soil can be worked
When the soil stays in a ball when squeezed, but easily releases
When you can comfortably sit barelegged on the ground or
When the depth of the earth is warm to the touch to a depth of 6 inches

Seeds need only moisture and warmth (and in the case of some plants, light) to germinate because they are self-contained systems. A seed contains not only the tiny embryo of the future plant but also endosperm, a tissue which stores enough food to keep the embryo alive in the dormant stage and for the first few weeks of growth until the first "true" leaves form. This accounts for the frequently given instruction of not fertilizing until the leaves develop because photosynthesis starts only then.

The best way to determine when the time is right for sowing seeds directly outdoors is to use a soil thermometer to measure the temperature of the soil itself.

Moving Outdoors

Lee Valley Propagation Guide
Plant	Planting Method	Ideal Soil Temp. (F)	Ideal Soil Temp. (C)	Days to Germinate	Weeks to Maturity	Additional Information
Asparagus	TR	60 to 85	16 to 29	14 to 21	Perennial	Can harvest after 2nd year.
Bean, Bush	DS	65 to 85	18 to 29	7 to 10	9	Pick regularly to encourage continued production.
Beet	DS	50 to 85	10 to 29	5 to 20	9	Best grown as spring and fall crops.
Broccoli	TR	70 to 75	21 to 24	10 to 14	9	Plant out deeply, with only 1”-2” showing.
Cabbage	TR	45 to 95	7 to 35	8 to 14	10	Root prune mid-season to prevent head from splitting.
Carrot	DS	45 to 85	7 to 20	7 to 20	10	Very small seed; mix with sand to aid in sowing.
Cauliflower	TR	45 to 85	8 to 14	8 to 14	10	Grow near celery to reduce cabbage worm.
Celery	TR	70 to 75	21 to 24	10 to 14	12	Mound soil as plant grows to blanche the stalks.
Cucumber	DS	65 to 95	18 to 35	7 to 10	6	Most varieties grow well on a trellis.
Eggplant	TR	75 to 90	24 to 32	10 to 15	4	Soak seeds overnight before planting.
Garlic	TR	45 to 85	7 to 29	5 to 14	22	Transplant in fall for next season’s crop.
Kale	DS	50 to 85	10 to 30	7 to 10	9	Most varieties are very cold tolerant.
Leek	TR	70 to 75	20 to 24	10 to 14	12	Plant out deeply, with only 1”-2” showing.
Lettuce, Leaf	DS	40 to 80	4 to 27	3 to 10	5	Lots of light for seedlings; shade for mid-season plants.
Melon	TR	75 to 95	24 to 35	5 to 7	10	Use compostable pot to minimize transplant shock.
Onion, Bulb	DS	50 to 95	10 to 35	5 to 14	14	Good companion plant that repels many insect pests.
Parsnip	DS	50 to 70	10 to 21	7 to 20	10	Harvest after a few frosts for improved flavor.
Pea	DS	45 to 75	7 to 24	7 to 20	9	Most varieties grow well on a trellis.
Pepper, Sweet	TR	65 to 95	18 to 35	10 to 15	10	Protect from low night temperatures.
Potato	DS	60 to 75	16 to 24	7 to 20	15	Pre-sprout seed potatoes before planting.
Pumpkin	DS	70 to 95	21 to 35	7 to 10	12	Heavy feeder; requires lots of compost/fertilizer.
Radish	DS	45 to 90	7 to 32	5 to 10	4	A late summer planting can be done to harvest in fall.
Spinach	DS	45 to 75	7 to 24	7 to 20	7	Sow multiple times for continuous harvest.
Squash, Summer	DS	70 to 95	21 to 35	7 to 10	6	Heavy feeder; requires lots of compost/fertilizer.
Squash, Winter	DS	70 to 95	21 to 35	7 to 10	10	Remove flowers after mid-summer to concentrate growth.
Swiss Chard	DS	50 to 85	10 to 29	7 to 20	8	Very ornamental.
Tomato	TR	60 to 85	16 to 29	8 to 10	10	Inconsistent watering may cause fruit to crack.
Turnip	DS	60 to 95	16 to 35	7 to 14	9	Plant onions nearby to deter root maggots.
DS – Direct Sow \| TR – Transplant (It is best to consult the info. on the back of the seed packet for specific types and varieties.)

Average Last Frost Dates

Burlington, ON – May 5	Niagara Falls, ON – May 11	Timmins, ON – June 9
Calgary, AB – June 1	Ottawa, ON – May 11	Toronto, ON – May 10
Coquitlam, BC – April 13	Quebec City, PQ – May 17	Vancouver, BC – April 1
Charlottetown, PE – May 22	Regina, SK – June 3	Vaughan, ON – May 9
Edmonton, AB – May 29	Saint John, NB – May 22	Victoria, BC – April 22
Halifax, NS – May 13	Saskatoon, SK – May 28	Waterloo, ON – May 13
Kelowna, BC – May 19	Sault Ste. Marie, ON – June 1	Windsor, ON –April 28
Kingston, ON – April 28	St. John’s, NF – June 6	Winnipeg, MB – May 28
London, ON – May 15	Sudbury, ON – May 21	Whitehorse, YT – June 12
Montreal, PQ – May 6	Thunder Bay, ON – June 22	Yellowknife, NT – May 31
Laval, PQ – May 6

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