Growing Guides

Perennial vegetables have generally undergone less breeding efforts over the millennia than other common vegetables. Seeds can have more "wild" tendencies, such as requiring cold stratification, or germinating erratically over a long period. But with a little knowledge and patience, I'm confident you can grow them from seed! And on the bright side, since many perennial vegetables live for years, you won't need to do this very often!

Please refer to the "Growing Instructions" at the bottom of each seed listing for specific growing and germination instructions for each variety. 

 

Direct Sown Seeds

Some seeds do best when they are sown directly in the garden, such as most root crops. However, starting out in a garden setting can be risky, due to slugs, birds, weeds, etc. I start most of my plants in containers either indoors or in an unheated greenhouse, then transplant them in the garden once they've grown a bit. Their bigger size gives them a better chance against slugs and pill bugs!

 

Seed Pre-treatment

Cold Stratification

Some varieties require a period of damp cold before they will sprout. In the wild, this ensures that seeds wait until after winter to germinate, when conditions are better for growing. The length of the cold requirement varies depending on the species, but usually is 30-90 days.

The easiest way to ensure that seeds get this treatment is to plant them in fall or late winter, and let nature do the work for you. I plant most of my cold germinators in late January or early February in an unheated greenhouse, in 4-inch pots. It's usually cold enough to stratify things throughout the end of March. It's ok if it gets below freezing. Lots of temperature variation seems to be beneficial.

You can also cold stratify indoors in the fridge (not freezer). There are lots of ways to do this, but I like to fold seeds up in paper towel, and seal in a labelled ziploc bag. Water just enough that the paper is damp, but drain out any excess water. Pop the seeds in the fridge and check often. Carefully remove any seeds that have sprouted, and pot them up. 

Alternately you can use damp clean sand, peat, coco coir, or vermiculite in a ziploc. Or try sowing in a small pot and putting the whole thing in the fridge. Just ensure it does not dry out.

Caucasian Spinach sown February 11 in an unheated greenhouse, sprouting March 19. 

 

Scarification

Some seeds require their seed coat to be damaged to germinate in a timely manner. Astragalus is a good example: I use nail clippers to nick a tiny sliver out of the seed coat (outer layer of seed) before soaking and then planting. This helps the seed to absorb water. You can also rub the seeds between 2 pieces of sandpaper instead. Be careful not to sand off too much of the seed coat.

If in doubt, err on the gentle side. Usually the seed will swell to double the size after 24 hours of soaking in water, and if any don't swell, you can abrade them a bit more aggressively and soak them again before sowing.

If you don't scarify seeds that require it, they will usually still sprout, but some may wait several months or longer before their seed coats weaken enough.

 

Starting Seeds in Containers

Seed Starting Mix

I recommend starting most seeds in a light (fluffy) low-nutrient, sterile medium that's made for starting seeds. I like to use Promix HP (High porosity), which is available at most garden centres, but anything made specifically for starting seeds should be fine. Ensure the mix is relatively sterile to reduce the chances of a bacteria or mold killing off the young seedlings.

If you watch YouTube videos based in Europe, they will often recommend starting seeds in compost. From what I've gathered, they are referring to a fluffy seed starting mix, NOT composted organic materials.

 

Containers

I like to start most of my seeds communally in 4 inch plastic pots. You can also use trays or cell-trays, or recycled containers. Make sure that whatever you are using has drainage holes in the bottom, and it big enough to hold enough soil to feed the plant for a few weeks. I find the 4 inch pot is the right size for starting the number of seeds I want for my garden, and it holds enough soil to feed the seedlings for several weeks. It also holds more moisture that a cell trays so I don't need to water as often. Larger pots can stay wet for too long. 

 

How to Sow Seeds

A general rule of thumb is to only sow seeds twice as deep as the seeds are wide. So for beans that are half an inch wide, you can plant them an inch deep. There is lots of wiggle room here, and different depths can provide different benefits and drawbacks in different situations. 

Tiny seeds should be sprinkled on top of the soil, and a light dusting of fine, dry medium sprinkled on top. Some seeds require light to germinate so should not be covered much if at all. Check each variety's growing instructions in the listing. 

After sowing, gently press down on the soil surface to ensure there is good contact between the seeds and the soil. 

 

Moisture

After seeding, make sure the soil is thoroughly moist. The best way to water pots or flats is to water from below- put the pots in a tray of water about an inch deep, and let the pots wick up water. Leave the pots in the water for 30-60 minutes or until you can see the soil surface become wet.

After that initial watering, make sure the soil remains moist but not soggy. Let the pots dry out slightly before watering again, but don't let it get bone dry. If plants are wilting, water right away. Avoid over-watering to keep away fungus gnats and damping off.

 

Light

Strong light is essential for seedlings started indoors. Light from a bright window is generally not enough. If plants get tall and spindly ("leggy") this means they are reaching for the light. Invest in some good grow lights to give your plants the best start if they will remain inside for long.

 

Heat

Different seeds will germinate best at different temperatures. Most seeds will germinate at room temperature or slightly warmer. A heat mat will speed up germination of warmth-lovers such as tomatoes and peppers. Some plants prefer cool temperatures to germinate, such as lettuce and cilantro.

 

Air Flow

Good air flow can prevent issues such as damping off or fungus gnats, and help seedlings develop strong stems. A regular indoor fan is great to provide some extra air flow if you're seeing these issues. A light breeze is all that's needed.

 

Potting Up

For some plants, such as tomatoes, they are started so early that they will need to be potted up into larger pots before it's warm enough to transplant them outdoors. The soil should have more nutrients this time, and it does not need to be sterile. I usually mix about 1/3 to 1/2 compost with promix for most plants. For tomatoes and peppers, I also add a sprinkle of organic granular fertilizer, such as Gaia's Green Organics all-purpose fertilizer. 

 

Transplanting Outdoors

When the time has come to put your plants outdoors, a period of "hardening off" can help reduce transplant shock if the plants have been coddled indoors for a long time. Essentially you want to gradually expose plants to the sun, wind, and rain to toughen them up a bit. Bring your seedlings outdoors to the shade for an hour or so, gradually increasing the time and level of sun over a week or two until your plants are in full sun for full day and night. Make sure it's warm enough outside to do this, depending on the variety. 

After hardening the plants off, transplant on a cloudy day, and water them in well.

Spoiler alert- I hardly ever harden off seedlings, but I will make them a make-shift shade structure if I transplant on a sunny day.

 

Please reach out if you have any questions about starting seeds.