Seed Starting - an irreverant primer

I am going to pause the exposé of rot to write something timely for us gardeners. Just when winter is at its bleakest, we open packages of promise and start to sow. My guide to breaking the rules.


Tomato plant ready for outdoor living.

1. Don't start your plants too EARLY!

No! Stop! Don't plant cucumbers now! It's bad! They might eat your house! Or at least scare the children with their weak, limp tendrils growing cave-light pale on your window sill. It's true, unless I had a fancy greenhouse, I wouldn't start cukes this early. It is way easier to sow in direct in the garden or to start in transplantable containers a couple weeks before setting out. However, I start strawberries in early winter and some plants need months of stratification to break dormancy so I sow them in the fall. This rule is mainly aimed at getting people in short season areas to start their tomatoes in April, or late March at the earliest, rather than in February.

I'll cop to planting tomatoes in February one year. You know, earliest possible last frost date of the beginning of May minus eight weeks gives you March so last week of February sounded reasonable. They did fine. The problem, as I see it, is if you are growing a tomato that tends to crop all at once such as determinates, then you might get a flush of flowers on your root confined seedlings, lowering your yield. There are even tomato varieties that are bred to withstand low indoor light, such as Red Robin, that will hopefully give you fruit in the dead of winter!

So when do I start seed? All year.


2. You MUST have indoor lights!

Indoor lights are good. It's like you have control of your very own sun. To get the maximum satisfaction out of them, I recommend having as many as you can afford in a compact space such as a tower, with the lights on a timer. The often quoted number is of light hours is around 16 but some people have them on round the clock whereas others claim that seedlings need nighttime. There is the question of plants who are sensitive to changes in day length but I'll leave that research for another day. Normally my seedlings get 12 hours because I have two shifts of trays. The lights should be about 2-3 inches above the seedlings.

Wimpy baby plants prefer things moist. I would suggest wick mats or some DIY instant water dispenser but then you might spend less time staring at your seedlings. The best way to avoid problems is early detection so stalk your plants!

You can use actual sun filtered through a window too. Most gardeners will tell you this is not ideal but it does work especially if you have sunny windows that face south(ish). However, I have had success overwintering perennial herbs like rosemary, bay and hot pepper in a north window.

What you really want is to give your seedlings the amount of sun that they have been adapted to thrive in, as soon as possible. When the weather is decent during the day (10C or more) I stick my seedlings along side my winter sown containers. This is just really early hardening off so I start with having them outside for just a little while, building up until the seedlings are hanging out in real sun most of the time. If they are cold hardy, I have probably wintersown them or planted them out already so this is really only for tender bedding plants.

If you have a season extension device like a greenhouse, polytunnel or coldframe then you can put your seedlings out sooner but remember to keep them slighly open on sunny days to avoid frying your plants. Also, outdoor containers will dry out faster than indoor ones.


Wintersown containers revealing seedlings in spring.

Wind is just as much of a shock to tender seedlings as real sun. Their stems were build to withstand the still, indoor air. To make them sturdier, you can set up an oscillating fan nearby or crack a window on nice days to let in the breeze. If my baby seedlings are going outdoors without the shelter of a greenhouse, I usually place them in a box with high sides to protect them from the wind until they have adjusted.

3. But what about the soil and the containers? TOO many choices!

I would suggest starting with the biggest size container that you plan on using for your plants. This will give you a better idea of how much space you need, disturb the roots less and be less work. As for what you use as a container, the world is your oyster as long as the pot has drainage holes (though I have been known to plant indoor seedlings in flats without drainage to keep in moisture longer but these don't go outside in the rain). For plants that resent root disturbance, such as melons, soil blocking, or compostable pots are probably ideal. Tap rooted plants like parsley need deeper pots than those with more lateral root growth like tomatoes. Plastic recyling day is when I get most of my seed starting paraphernalia. The pop bottle is a classic wintersown greenhouse but I also like yoghurt tubs for large seedlings, and fruit boxes to grow flats of seedlings.

As for soil, you could use your own if you are lucky enough to be able to thrust a trowel into it at seed starting time, or you could make a mix or purchase something. I admit to using whatever is available. My outdoor soil is often stickier than the fluffy, soilless stuff from the stores so dries harder. Mixes that are high in organic matter hold their moisture for a long time which is a benefit. I avoid mixes with fertilizers or other chemicals. If you are worried that your soil may contain organisms that might cause die back in your plants, you can cook your soil to sterilize it.

4. Seed starting is too HARD!

Nah. If it was then I would probably have given it up. Seeds are designed to grow so given the right conditions and a little attention from you, they'll do their thing.

Q&A for specific problems

• Can't afford lights and don't have a southern window: Wintersow or half outdoor grow! Try it anyhow, you never know, it might work.
• Cat eats the seedlings - Grow in a cage.
• Seedlings always die off - A solution of hydrogen peroxide, garlic or other antifungal can help. Check the soil for root eating pests, sterilize soil and pots. Watch your watering level.
• Seeds don't sprout - Look up the longevity of the seeds, maybe they're old. It's also possible that they require special conditions for germination including cold, heat, scarification (scratching the seed coat) or other pretreatment such as overnight soaking. Err on the side of caution with small seeds and surface sow. Some plants germinate better in light such as lettuce whereas others prefer darkness. Less cultivated varieties, including lots of herbs, often germinate erratically, over a long period of time. Try pre-sprouting to test seed quality or to isolate some seeds for special treatment. Peppers germinate much faster using pre-sprouting in a warm area.
• Seedlings always look a bit sickly - If their colour is off then they might be suffering from nutrient deficiences either because their growth medium is lacking or because they are too cold. Correct with some compost tea or by placing somewhere warmer.
• Seedlings have long, weak stems - This is usually caused by insufficient light. Try growing in a season extension device part of the day, wintersow, and gradually expose to air currents. When transplanting, some plants can have their stems buried such as tomatoes so they are less likely to flop over.
• Plants never give me fruit / don't ripen properly even though I start them early - You might need to look for a short season variety of what you are growing or one that is more adapted to your locale whether that be foggy east coast or the blinding light and tumbling nighttime temperatures on the side of a mountain. Sweet potatoes started from tubers at the store will probably not crop well here but the cultivar Georgia Jet will give a good harvest most years. It is possible that the plant you covet just won't grow well in your climate, or your garden, such as tender biennial red beaded broccolis. I know, I want to grow them too.
• But I really just don't want to start my own seeds - There are small growers that will provide veggie starts for you and lots of seeds that do best when planted in situ. Check with local seed suppliers.

My Seed Starting Schedule
- updated - I'll add division schedules at some point.

January

• Sow plants that need 10-12 weeks headstart if they are set out before last frost or are erratic germinators. For example, violas
• Sow plants that you are tricking into thinking are two years old. Ex. Globe Artichoke.
• Wintersow frost hardy plants that prefer stratificaiton.

February

• Alliums such as onions and leeks
• Plants that need 10-12 weeks headstart but are set out in warm weather
• Pre-sprouting hot peppers
• Wintersown containers

March

• Wintersow plants that don't take full frost
• In mid-March, plants that need an 8-10 week headstart
• Greens in polytunnel / season extension device
• Near the end of the month, plants that need an 6-8 week headstart such as tomatoes, eggplants, sweet peppers, other solanum berries. Sometimes cabbage and broccoli starts as well if need a long season

April

• More tomatoes and other plants that need 6 weeks heastart indoors
• Cabbage and broccoli starts
• Sow peas, radish parsnips in the ground
• Cold season greens in polytunnel or in ground if it is warm and dry enough
• Leeks and onion transplants in the ground with a row cover if cold
• Near the end of the month, start sowing other root crops like carrot, oyster root
• Start lettuce and half hardy greens and herbs in the garden.
• Plant out 4 week out brassica starts

May

• Last frost will be somewhere is somewhere near the beginning of May, watch the weatehr
• At the beginning of the month, plant potatoes
• Plant more broccoli and cabbage seedlings or seeds
• Start long season melons, squash or other heat loving crops that need a month headstart
• Direct sow into the garden squash and beans near the end of the month when the soil is warm.
• All hot loving herbs and flowers can be sown near the end of the month.
• Transplant solanums like peppers, tomato and eggplant into warm soil after last frost.
• Can plant a second sowing of greens, or roots for baby vegetable production or succession sowing. I tend to harvest leaves rather than whole plants from greens so don't often do this.
• Look for self sown seedlings to thin or transplant
• Check your nursery bed for growth

June

• Transplant melon, squash and sweet potato starts in warm beds
• Start long season crops that will be ready for fall such as Brussel Sprouts.
• Sometimes I sow a second crop of beans, summer squash about a month after the first and a second crop of peas.

July

• Time to start thinking seriously about the fall garden. Start in a nursery bed or indoors starts of cauliflower, cabbage.
• Sow into their final position tap rooted plants for fall harvest like carrots, florence fennel or coriander.

August

• Sow quick growing greens in greenhouse or cold tunnel space.
• Sow plants that you want to overwinter as seedlings like spinach.
• Scatter ripe seeds of self seeders where you want them to grow.

September

• Prepare and sow nursery bed in time for fall rains
• Scatter seed from self seeders that appreciate stratification.

October - December

• Plant garlic and other perennial overwintering onions or tubers like Jeruselum Artichoke.
• Make sure all fruit seed and other seed that does best with moist stratification or oscillating temperatures are sown in mice proof containers before hard frost.
• Wintersow in a sheltered snowing location that can take or prefer frost.

Self sowng salad ingredients.

Common Veggies & Herbs, tips

Amaranth - Likes heat so start in situ after last frost or give a short headstart. More from Salt Spring Seeds about Amaranth and Quinoa
Basil - Needs heat and warmth to grow well. Start early only if you can provide these two requirements otherwise start using the half outdoor method or in situ. They grow well from seed planted in warm soil.
Beans - They do not tolerate frost. Plant after soil is warm and after last frost. For staggered harvest, try some early bush types along with some pole beans.
Cabbage - There are short and long season varieties. I find that this technique works best for me. Can either be sown direct into the garden or started as transplants. They grow and head well in cooler weather.
Carrots - Can be planted anytime that the soil is moist and there is no hard frost but ensure that you have enough growing time for them to bulk up. They don't germinate well in the dry soils of summer. I normally start my first crop in late April.
Cauliflower - Best grown as a fall crop here. Start in mid-summer for fall maturation.
Chicory - To get the classic head, these are grown as fall crops but they are perennial so sow and let grow.
Chinese Cabbage - Another veggie that bolts in hot weather. I usually have some that have overwintered and self seed. Another crop best grown to mature in fall or in the polytunnel/coldframe/greenhouse. Coleman's Four Season Garden is a great resource.
Chives, garlic and normal - These are perennials which can be started very early in spring or can be sown direct in the garden. If it can be started outside, I usually do. It's just easier.
Coriander - There are varieties that are grown for seed and some for leaf. Longest leafing plants, for me, were grown in part shade in moist soil. Will bolt in hot weather. Seed every few weeks for a more continuous harvest. Will self seed.
Corn - Plant in situ after last frost.
Dill - Frequent self seeder. Plant at the same time as carrots.
Eggplant - Started around the same time as tomatoes and planted out after last frost. Not a thrifty plant: needs heat, moisture and fertility. Give it your sunniest, warmest position here in the north. It helps to prewarm the bed with clear plastic or incorporate half rotted compost/manure nearby. Variety is imoprtant here too. Choose a short season one. Some of the long asians and applegreen have both cropped well for me.
Fennel - Florence or bulbing fennel is another great candidate for the fall garden so start in summer to mature in the cooler part of the growing season.
Garlic - Plant this after first frost but before ground is frozen. You can grow garlic from the bulblets that develop at the top of the scapes but it will take a couple years for them to bulk up.
Kale - It is quite possible to get a self seeding population of kale around here. Choose a hardy variety and seed two years in a row as they are biennial. The seedlings are normally up and growing by late spring. I would direct sow these.
Lettuce - Succession sow whenever there is no hard frost. Choose varieties that are suited for different times of the year. Often lance leaf open types do better in summer whereas the cripser heads bulk up better in cool weather.

Mustard Greens - Lots of varieties have excellent cold tolerance but bolt quickly in the heat. I let mine go feral and eat when available in the spring and fall.
Melon - Will not take any frost. Choose short season varieties and put into prewarmed beds with either manure or plastic (see Eggplants). You could capture even more heat by building a frame that angles south for the vines to scramble over. These can be prestarted in transplantable pots several weeks to a month before setting out.

Oyster Root - Salsify is the biennial and Scorzonera (I recommend) is the perennial with edible root/leaves. Sow at the same time as carrots.
Orach - These should be self sowing in your garden given half the chance. Start in warm, wet spring. Can also be fall sown.
Onion - Start in February, transplant out to the garden after hard frosts. I usually put mine out sometime in April.
Peas - I plant as soon as the ground can be worked but I've been chastised by growers in climates with heavy, wet soil saying that their peas would rot if planted too early in spring so use your conditions as a gage. Plant when the soil is 'workable.' Plants grow best in cool weather. I often grow a fall crop mostly for the edible green shoots.
Parsley - Some people suggest presoaking to speed up germination which can be slow and erratic. You can start this one inside but it grows well when sown in situ in spring. To be honest, I've only started this plant a couple of times as it was a very good self seeder for me.
Parsnips - I love parsnips so much. I plant these as soon as the ground can be worked in the spring.
Peppers, hot - I presprout these in February and grow under lights in a warm place. Plant out after last frost.
Peppers, sweet - Presprout and grow in March with Eggplants.
Potatoes - I'm a novice with True Potato Seed (TPS) Here's someone who knows more. Tubers can be planted a week or so before last frost.
Potato Onions, Walking/Topsetting Onions - If it can overwinter in the ground, plant in early fall.
Radish - I always forget about this veggie as I'm not a fan but I do sprinkle them around the early spring garden.
Spinach - Cold season crop great for fall, spring or polytunnel gardens. Direct sow.
Squash - Choose a shorter season variety though with about 120 frost free days, we have lots of choice. These are planted after last frost in warm soil. You can use transplants as in melons.
Sweet Potatoes - Grown normally from slips produced by the tubers, they should be planted in the warmest, sunniest part of the garden. See Eggplant.
Swiss Chard - I half outdoor grow these or start in situ in late spring.
Tomatoes - Start about 6-8 weeks before last frost which is the end of March/April. Stems can be partially buried if you have a floppy plant, set deep or plant diagonally. Try wintersowing short season or sauce varieties too.
Watermelon - See melon.
Other - Want info on a specific odd ball veggie I've mentioned in the past, please email or comment and I'll add it to the list or maybe I'll make another list?

* Half outdoor sow: I set outdoors during the day while warm (usually above 5C if under a ventilated cloche, otherwise when over 10C or so) and inside at night. I start to do this in late March/ early April.

Daphne's Dandelions writes a great post on seed starting

-- edited to add --

I Wet My Plants - Great Kemptville Gardener that I have the pleasure of bumping into during Seedy Days and other garden festivals has put up a couple posts on seed starting including a seed starting calculator.

Sowing Seeds, including difficult plants by JDHudson