March 29, 2013

My Tips on Starting Seeds

Celery seedlings must be started early, these were planted on February 1st, and are now ready for transplanting
into individual pots before being hardened off and set out into the garden.

Fair Warning - These tips for starting seeds which I am about to share are different than many which you will see from other garden bloggers. - growing plants is a science and seed starting in particular, can be complex, as much as it can be simple.  I want to share my most helpful tips with those of you who might be planning your vegetable gardens. In our world of Pinterest and pretty pictures of egg shell pots with mini moss gardens, when it comes to seed starting, there are no guarantees - seeds cane be fussy, young plants can die practically overnight from fungus, and even malnutrition. When it comes to starting your own food crops or even flowers - please, don't mess around - seed starting is serious business, and I am about to share with you my best hints and tips to help you achieve greater success.

Seed starting can be fun - especially if you are a new gardener, and even more so if you have your kids helping you. I know many moms treat seed starting as a craft, but rather than make it an art projet, seed starting can also be an opportunity to teach science, or, a valuable lesson on 'how-to-do-things-right' – a skill we often forget in our disposable, DIY culture of superficiality and sound-byte practices. One cannot rush seed starting, one cannot cheat, since seed starting IS science - it's a biology lesson waiting to happen.

To make things easier for you, I designed this poster showing the basic seed-starting facts for a few of the most common vegetables. Save in, pin it, or print it out to use as a guide.

Before I start, I like to do a little ( or a lot!) of research about what conditions the seeds which I am to sow, may require. Even for experienced gardeners, starting seeds successfully and growing them on requires some do- diligence.  Search on-line, and use the most informative sites such as your local county extension service, plant society forums and university sites rather than most blogs, at least at first. Later, you may want to visit a few of your most favorite and trusted blogs to see if there might be something that was left out of the techy information.

What I am trying to help you avoid, is something that we all do when given a stack of seeds - that is, to in the interest of time, just tear them all open, and sow them in any old soil, and water them. This may work for the easiest of seeds such as beans and tomatoes, but we all learn as gardeners, that even the most challenging seed can be germinated - all you need to know, is what the particular species which you are sowing, requires - environmentally ( temperature, moisture, soil). 

I will  admit to you all, that even I with over 40 years of gardening experience, find seed starting as perhaps the single most challenging skill when it comes to gardening - it's where I still have much to learn ( that is, until I try grafting!).

I say this all because I see many phrases advice being shared on-line such as like "just plant the seeds in dirt and water, and stand back".These broad statement are generalized, and they are not only misleading, they are often wrong.  The entire plant world grows from seeds, and almost each one requires something different culturally. The goal here is to achieve optimum results - not just a few seeds germinating. Often, a shift in soil temperature just while germinating may make all the difference in the world.

This snapdragon seedling not only needs clean soil, and cool temperatures while it is growing if it is even going to compete with the ones found at nurseries in the spring with thick stems and dense growth due to rooting
hormones and plant growth regulators, it will also need a good dose of iron - something petunias also need.

Some seeds come from plants that grow in tropical climates in South Africa or South America (melons and cucumbers) demand soil temperatures near 80º F, but then again, so do many cold weather crops that you may think need cold soil in which to germinate - cabbage and broccoli come to mind.  Other plants such as those from central America (tomatoes, zinnias and Dahlias), benefit from light, or surface sown, yet need to be covered with cardboard to block out any light 0 such as Scabiosa. With your garden hosting plants from all over our planet, from South East Asia, China or even from the dry mountainous areas of Turkey. I like to think of seed starting as managing a zoo - where every animal comes from a different environment, penguins to jungle cats, and each need different stimuli and environmental conditions in which to grow properly. 

I know, I know - I need to order new labels! I can now master many hard-to-grow seeds, such as these Primula
sikkimensis, but I am not above cheating when it comes to my perennial seeds - see that packet on the right? It's
 from Jelitto seeds, and one of their pre-chilled Gold Nugget Seed collection. No need to refrigerate,
just sow and grow - and in no time, one can have hundreds of fall-blooming anemone plants.

My 10 tips for starting seeds.

1. Use proper containers for optimum results. Use deep seed pots for tap-rooted veggies like Artichokes, or wide pots for fibrous rooted veggies like celery. People - Enough with the up cycling when it comes to producing the finest vegetable seedlings.

It may make you feel good to recycle white plastic yogurt containers, toilet paper tubes, egg shells etc. ( and I'll admit that it might be a pet peeve of mine and that there may be nothing wring with using yogurt cups or egg shells to start seeds)-  but there are other things to consider - mainly, excellent root growth ( sometimes difficult in white or transparent plastic pots without the use of root hormones) and what about plants that need deep root runs? 

2. Find out what the optimum soil temperature should be for your seeds to germinate - remember, it's different for each type of plant that you grow.

Know what temperature you seed germinates best at is crucial.  Blindly opening a packet of seeds, and then sowing seed before knowing what it needs is perhaps the greatest error any gardener can make. Lettuce seed germinates best at 40º and poorly at 73º, cabbage seed germinates best at 85º, but then requires bright light a cold temperatures in order to grow well – difficult to do under artificial light systems.  Some seeds require stratification ( a cold period), some seeds need boiling water poured over them.  Learn first, and then practice.Cabbage may need to germinate hot, but then stay cool, only to be set out into the garden near your frost free date, but something like lettuce not only prefers to germinate near freezing, the seed will often go dormant once the temperatures rise into the 70ºs, which may simply mean that you will need to sow lettuce straight into the garden, but not ever under lights in the house. 

3. Once your seeds have sprouted, then find out what temperature your seedlings need to grow at - as this is often different than the germination temperature. 

Broccoli may like cool growing temps in the spring, but few people know that need to germinate in hot soil, but then it needs to grow-on in cool conditions, eventually the strong seedlings can be set out into the garden near your frost free date. Yet lettuce germinates best when temperatures are near freezing, the seed hates warmth so much, that it will actually go dormant once the temperatures rise into the 70ºs, so sowing lettuce straight into the garden in March will ensure that you achieve the maximum germination rate.

4. Use sterile soilless growing media, and yes, I advise not using coir for seed sowing. 

Seedlings are like premature babies, and they need clean, sterile  bedding and spotlessly clean diapers or they will get sick. Be a good parent, and you won't get fungus gnats, green algae or insects because poor cultural conditions will encourage all of these things. Start with sterile soil-less mix, which means that it’s been pasturized or heated, to kill all of the nasty stuff, and the good stuff will them be added if you can find an excellent mix. While on the subject of soil – perhaps the most controversial subject that there is in gardening today next to fertilizer and insecticide - all I can tell you is what I use –  Pro Mix BX with mycorrhizae. Yeah, it’s a peat based mix, and yes, it is commercial ( but I have yet to find a mix at a Home Depot or Lowes that doesn't look like it was made with pine bark, black hair dye and garbage. 

So proceed carefully here. There are many Pro Mix blends, and the one generally available at retail in small bags is also not the same mixture, so you might be on your own here. I stay far, far away from coir products ( I just think that they are bad for plants in my opinion – I’ve killed more plants with coir than any other soiless product, and the way it is produced in India isn't all that good for the environment either ( let alone it's carbon footprint). In a year I will be creating all of my own soil mixes without peat, but for now, I still use peat. My two bales  are my contribution to global warming. 
The ideal mix is generally impossible for most people to create - garden soil baked or steamed to kill the nasties, mixed with composted Beech leaves, sharp sand and you could end up with the finest seedlings of all, but the professionals use a virtually clean peat mix, drenched with fungicides, starting with chemicals to stimulate first root growth, and then chemicals to shorten the cell growth so that stems become thick, and leaves dense ( think of those awesome, "healthy looking" tomato plants you will soon see at the big box store). There are chem's to stimulate flower growth so that the flats will sell in full bloom, and you know the results. My use of peat based mix and some water soluble professional fertilizer may be frowned upon by some, but it doesn't come close to what commercial growers use. Be realistic, be responsible, be serious about what you grow, and I believe that there is a middle ground.

5. Fertilize often ( weekly) and use the right formula for the right plant.

And here is another touchy subject with those who are not serious gardeners. Just don't use 10-10-10. Read-up on what the professionals use, and be careful with those home remedies!!! Look. Save your chamomile tea spray for your evening tea and not to spritz on your seedlings to discourage fungus gnats – these nasty while lies are being spread on social media sites faster than Justin Bieber comments. The real reason why you have fungus gnats is because  your soil is too wet, and you are just making it worse by wetting it more. Forget completely about molasses fertilizer, Epsom Salt fertilizer ( it's just magnesium, and most likely, your seedlings don't need just magnesium), - I will say it again – GARDENING IS SCIENCE, and thus, plant nutrition is far too great a subject for me to cover in this post - all I will say is my life changed once I took the time to reseach exactly what formula my pansies, tomatoes or celery needed, and pay attention to what stage of growth they will need a certain formula.  No tea bags, no crushed egg shells, no beer.

Gardening is a science, not a craft.

Baby Snapdragons ready to be transplanted into flats. These were sown in February, and now they have deep, strong roots due to a fertilizer formula that is 5.17.24, high phosphorus, low nitrogen.

I’d love to hear from you, if there is one that you love- I have heard that the Lobster compost is good, and Oh yes, I like the composted peanut hull mixes, but again, I am sticking with ProMix for now, black plastic containers, or dark green Kord pots. The only recycled pot I do use are some black plastic take-out containers from our local Chinese delivery, they work well for seedlings, but beyond that, I use clean, new pots.

Yes, I an still growing crazy rare things too! Two years after sowing, this wild collected
Narcissus is just germinating! Yay!


  1. I've been growing seeds of annuals and perennials for three years, some successes and some abject failures. Your 'it's a science' message tells me that I can do better with the right tools and better information. I've used information from the seed packet, from my local hort society website (Ontario Rock Garden & Hardy Plant Society - I believe you're speaking to us this fall) and from Tom Clothier's seed site. I don't quite understand where you get fertilizing info from the pros. Could you point me in the right direction? Thank you.

    BTW I've been able to germinate a number of seeds which then get very spindly, fall over and die. Not sure what to do about this, the books I've read don't seem to touch on this point or seem to assume that I'll know how to handle this stage of the process. Would love to hear more from you about growing-from-seed step by step.

    So far I have galanthus, eranthis hyemalis, crocus and a lone hepatica nobilis in bloom. Spring is here!

  2. I have to confess that I approach seed germinating more like a craft, maybe if I had a green house I would be more scientific.

    I notice that tomatoes are germinating in my garden wherever I spread my compost, and it is not 80F yet, so I think they are less fussy about the temp that most people think. I have germinated seeds in many different media, the one I like the most is "recycled" from the restaurant where I worked, so it is not sterile. I would bring home the tray of mix once they cut all the shoots, I have had amazing results with it, I wish I knew its composition.I normally don't fertilize seedlings, and I know I should after the first two weeks. I heard though that seeds don't need any fertilizer to germinate, but only later when they are few weeks old.

    To be the devil's advocate I have transplanted many seeds that are normally recommended for direct sowing and have had good results when maintaining the root ball not too wet nor too dry. Peas need to be transplanted in my garden because of the slugs and hungry birds.

    Wishing for a green house....

  3. Hi Laura, Thanks for your notes! Seeds don't need fertilizer to germinate, and they will all grow without fertilizer - but I am talking about optimum conditions - you know- when you spend 3 months raising seedlings, and then when you visit your local hardware store and they suddenly have the same plant but they somehow look amazingly healthy with thick stems, and dense growth? That happens to me all of the time, but I don't want to use growth hormones. Like anything else, there are many ways to do things, I just wanted to share better ways for those who may wish to enhance their skills. I will go into more detail in a later post. Thanks!

  4. LauraH_ can I tell you how excited I am to be speaking in Ontario this fall? As for snooping into where the pro's get their info from, I use textbooks, wholesale nursery sites like Griffin Greenhouses, and the major fertilizer supply sites - Google Peters Professional Peat Lite fertilizer, and you will see many special blends - some for geraniums, some just for pansies, etc. For bulbs, I choose one with high potash, and low nitrogen.Here - only siberian crocus still, still waiting for my Eranthis to emerge ( if the puppies have not crushed it!).

  5. This is such a great article on starting seeds! Thanks for sharing. The infographic is also wonderful. I've never had much patience with seeds (generally I just start with already growing plants) so I'm going to give your tips a try this year and see what happens!

  6. A science indeed. I can handle most annuals just fine, even a few perennials, but trees just give me problems. Maples pop just fine like the veggies and flowers, but they seem to be about it. I have had good results with barrel and prickly pear cacti only if I transplant them within a week of sprouting. I have yet to successfully start a Joshua Tree or any yuccas, even with the "cactus helper" technique. In contrast, I can plant nearly anything outside and take a gamble with the frost schedule and seem to have much better fortunes in general. A science with wacky math!

  7. Thank you for this information, a new gardner fan from Michigan.

  8. Since you asked...I like Metro Mix 360. Promix is mostly peat and it holds so much water that the humidity kills stuff here in the Southeast.

  9. Hi Caley,
    I never heard of Metro Mix - I am going to see if I can try it. Thanks for sharing!

  10. great post! thank you! a good scold about SCIENCE! never hurt anybody. also loving that chart!

  11. Crushed egg shells is scientific. It's not hokum. Crushed egg shells are mostly calcium. Soils low in calcium tend to not support nightshades (tomatoes, peppers, eggplants, potatoes, etc...) as well as soils with good calcium content. Adding crushed eggshells prevents bottom end rot inexpensively.

  12. Hmm, interesting. I use recycled garden pots all the time - with seed raising mix and have pretty good success. I do try to make sure that they are appropriate sizes though. And I make my own labels out of recycled materials. One great tip that I have started using, from someone who did a comparison study (almost scientific), was to water the seedlings with warm water - this has made for phenomenal root growth this year. Is that something you do?


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