Saturday, April 2, 2011

Seed Starting Secrets and Stuff

Some people have had great success starting plants indoors from seed. Some people have failed miserably. Unfortunately I was one of the latter, but I wasn't about to give up and claim a black thumb. Since I earn my keep as a horticulturist, having strong healthy plants I've grown myself is a matter of professional pride. I started to glean information where I could - books, garden club meetings, the internet. I now have happy healthy seedlings every year (for the most part - there are always some mishaps*,) and below you'll find a lot of the tips and tricks I picked up in my quest for a greener thumb. Maybe they'll make your thumb a little greener too.

1. Select plants and varieties that do well in your area. I would love to grow Brandywine tomatoes, but there's really no hope in trying to get them to produce fruit in Alaska unless you own a greenhouse, which I don't. So I stick with 'Stupice' tomatoes, which aren't quite as heavenly but do very well in cold summer climates. If you don't know what grows well in your area, ask a knowledgeable garden center employee or a master gardener.

2. Sterilize everything! Pots and cell packs and trays and all that jazz. A 10% bleach solution works well for me. Don't reuse soil when starting seeds. Your little babies are too vulnerable to diseases such as damping off.**

Yup. My bathtub is yellow.

3. Follow package directions. Unless, of course, you know better. Alaska has a short season so I start things inside earlier than the package directs. (And still I don't get some things to bloom until September.) But in general if it says to plant a seed 1/8" deep, don't put it down an inch. Some plants need light to germinate and vice versa. 

4. Don't expect 100% germination. It's a good idea to over plant if you need a specific number of plants. I tend to over plant by 20% unless I've had good/bad luck with that particular species in the past.

5. Label everything! It's really hard to tell some seedlings apart, especially if you have multiple varieties of the same plant. (IE purple, pink, and yellow petunias.)

6. Keep the light bright and the humidity up. You can make mini greenhouses or cover with clear plastic wrap. Use fluorescent or LED lights and keep them close to the plants, unless things are getting too hot. (Although they shouldn't with those types of bulbs.) Many people like to use one cool fluorescent and one warm to get a full light spectrum, or you can use daylight spectrum bulbs.

I leave the lid on to keep the humidity up before the seeds sprout.
Then I remove the lid for air circulation once things germinate.

I keep the plants REALLY close to the lights unless they are starting to looked scorched or bleached out. Shade loving plants like begonias don't like to be too close. Everything else needs it to grow well.

7. Don't fertilize for the first couple weeks after germination. Then fertilize according to package directions or whatever suits you. (I actually try to hold back on the fertilizer so things don't get too big too fast. I only have so much room.) Watch for nutrient deficiencies.

Although this variety of snapdragon has a natural purple tinge to the leaves, purple or reddish leaves could be a sign of phosphorus deficiency. Pale green leaves tend to mean a nitrogen deficiency.

8. Transplant when needed. Most plants grow out of those little Jiffy peat plugs in the time it takes to bake a batch of brownies. Unless you want pathetic stunted little Quasimodo plants, give them a home with more root space after some true leaves develop. Some plants can stay in little cell packs for a while (annuals like pansies, lettuces, forget-me-nots, etc.) Others need to be potted to 4", 6" or even larger sized pots (tomatoes, many perennials, supertunias, etc.)

9. Watch the watering.
Seedlings in little cell packs dry out fast! I check mine once a day. For unsprouted or newly sprouted seeds I gently mist water with a spray bottle. Older seedlings can handle being watered with a pitcher. Don't keep things too soggy or you'll get diseases and gnats and all sorts of unpleasantness.

10. A little adversity makes for sturdy plants. I have an oscillating fan that I turn on for an hour or so every day. It increases air circulation, which is always a good thing, and it encourages all the little suckers to put on some muscle and thicken up their stems.

11. Watch for pests, especially things like aphids, whitefly, and spider mites. And it my case, parrots.

The beak-shaped damage leaves no doubt as to the culprit!

11. Harden off your plants before planting them outside. If you've never done this or don't know what I'm talking about, I'll probably cover it in a later post. But the general idea is to gradually get a plant used to its new environment before permanently moving it there. This is especially important for plants grown under artificial light, since they'll burn if you put them straight into bright sunlight for too long at first.

So that's it. Do you guys have any hints to share? Any great successes for failures? Good luck with your seeds, and have a happy spring!***

*like when my parrot lands on the edge of a flat of newly planted seeds and sends it all cascading onto the carpet. So no variegated Korean Violets this year.

**I was lazy and didn't sterilize anything last year and lost over half my seedlings. That, and I had algae growing everywhere. It was nasty.

***Well, not yet. But soon. Oh, so soon!


  1. I was a little too successful at growing Delphiniums from seed one year. I lost count after eighty. After spending the next two summers staking, I learned my lesson and gave all but two or three away.

    I have a pink bathtub, so don't feel too bad about ol' yeller....

    Christine in Anchorage

  2. I can't even imagine staking eighty delphiniums! What a (beautiful) nightmare! Like you, I find two or three in my yard to be quite enough.

    And yeah, I'd take yellow over pink too! At least in the bathroom, that is; pink in the garden is entirely different :-)

  3. Super helpful. I have had only failure, pretty much, but I've done pretty much everything you say not to. I didn't sterilize (and, um, I forgot to this year, to), I recycled soil, I didn't use the correct light (I thought my Wal-Mart special of a $.75-clearance desk light would be great!), and I used the Jiffy tray. I think that kept them dry, and then I also sprayed them--even before they were sprouted--and even though it was a mister-type bottle, they all either dried out or damped off. Awful, and so discouraging! But I am using your system this year.

    I also switched out the light that I told you was melting the lids. I think they were LED, but whatever. I'm also bottom watering, just putting some water on the bottom of those spinach containers for the plants to suck up. Question there: Should I just keep half an inch or so of water down there at all times, or only when needed? Is there a chance that they'll get root rot or anything?

    More questions:

    1. I planted things about 10 days ago. We have a short growing season like you do (yes, Tundra Monkey, I tell people that I live in the tundra, too!). Do I have any hope of seeing anything bloom this year? And should I be seeing anything yet? (I'm not.)

    2. I'm planting everything in the 4" pots. But due to space, I decided I needed to economize. I put four little divots in each 4" pot. Was that wrong of me? I just don't have enough space or containerage for all the seedlings I want to grow.

    3. I planted sedum. And then I read on the package that they may not germinate for 1-2 years?! What the! Seriously? Should I even hope for anything there? Obviously not doing those again...

    4. I've also used some seeds that are a year or two old. I've stored them in a washed and dried, large yogurt container, in a cool, dry, dark place. When do seeds go "bad"? At what point should I get rid of things?

    p.s. More, more, Gretchen! I love this blog!

  4. Erin, you always ask such great questions! I've totally encountered all these things before in my seed starting experiments, so I know how you feel. (The sedum one totally made me laugh.)

    I hope you don't mind, but I'm going to paste these questions into my next post and answer them there. Since I have an audience of about four people right now, so I'm hoping it won't bother you too much :o)