When gardening, it’s an unavoidable fact that you will have successes as well as failures. Failures can be caused by an outside force you have no control over (cat digging up your seedlings, a tray of tiny green shoots getting knocked off the table by accident, etc.), but it can also be caused by things you do have control over. Overwatering, under watering, not enough light, and more. These mistakes are very common, and not something to feel bad about!
1. Seeds fail to germinate?
Possible Causes
Temperature of the soil is too hot or too cold. Most seeds like a soil temperature of around 65°-75°F. In general, the warmer the temperature, the faster the seed will germinate. Please note that even if the air feels warm, the soil may still be chilly. We often recommend a bottom heat source.
Seeds rotting in the soil means it was too wet. Your soil should be moist, but not soaked.
Planting depth of the seeds – plant too deeply, and germinating seeds have a hard time reaching the surface or light is unable to reach the seed. Plant too shallow, and too much light can damage the seed. Most seed packets will instruct you on how deep to plant your seed!
Growing medium was allowed to dry out. Your soil should remain moistened but not drenched, and not bone dry.
‘Damping off’ disease, which can affect the seeds before they germinate. Damping off occurs when a pathogen that thrives on too-wet conditions is able to grow and kill the seeds before they can emerge.
Remember-Pinetree stand behind its products and we will always work with you if you have concerns about germination of seeds you have purchased from us.
2. Seedlings fall over or start to decay at soil level
This is a sign of damping-off disease (fungus organisms that attack seeds and young seedlings, ultimately killing them). Some causes of damping-off are:
Cold, wet soil
Poor soil drainage
Poor air circulation
Unsterilized soil mix, or reusing soil from previous seed starting
Dirty growing containers
Stress from low light
3. Leaves start to curl under, growth appears stunted or dwarfed
Possible Causes
Too much light. Seedlings need a ‘rest’ period, which is why it is suggested to only provide 14-16 hours of light.
Over or under fertilization. Too little nutrients can stunt growth, too much much nutrition can damage the roots and prevent the seedling from taking in water.
Low temperatures. Most seeds like a soil temperature of around 65°-75°.
Excessive moisture and overwatering. If the soil remains consistently wet, it can rot the roots and prevent the seed from taking in water. It may look like your seed needs water, but in actuality, it needs anything but! Make sure to test the moisture of your soil by feeling with your fingers. Soil should be moist but not soaked.
4. Seedlings have pale, discolored leaves; or leggy, spindly growth
Possible Causes
Insufficient lighting, or light source too far from your seedlings
Fertilizer burn from adding too much fertilizer, which can damage the plant's root system
Excessive watering
Nutrient deficiency – check the growing medium you are using to find out if nutrients are supplied in the mix. Some have tiny amounts to just get seedlings going, which means you then have to supply the rest until planted out in the garden.
Overcrowding of seedlings. Be sure to thin your seedlings to prevent this.
Temperatures too high. Most seeds like a soil temperature of around 65°-75°.
5. When transplanting you see poorly developed root systems
Possible Causes
Poor drainage
Low soil fertility
Damage from fertilizer salts, a.k.a. ‘fertilizer burn’, by adding too much fertilizer
Low soil temperatures. Most seeds like a soil temperature of around 65°-75°.
Compacted soil (lack of air space in growing medium), which can arise from overwatering and poor drainage.
6. Moss or mold is growing on your medium
Possible Causes
Lack of air circulation. Set a fan up to move air around your plants
Excessive moisture. If the soil remains consistently wet, it can rot the roots and prevent the seed from taking in water. It may look like your seed needs water, but in actuality, it needs anything but! Make sure to test the moisture of your soil by feeling with your fingers. Soil should be moist but not soaked.
7. Trying playing some tunes for your seedlings
We know that there is no proof to back this up but have you thought about playing some of Pinetree's certified Spotify playlists to help the seedlings grow?
Here’s a short message of encouragement from our master gardener, Jaci:
“As a gardener, I know how it can be discouraging it can be when some seedlings fail or don’t look perfect. Try not to dwell on it too long; just take the opportunity to gain some knowledge on the possible underlying causes so you can be successful in the seasons ahead. I have been gardening for nearly 20 years, and each year still brings new learning experiences for me.”
Some quick tips for making sure your seedlings flourish!
Once your seedlings have 2-3 sets of leaves, the most important thing to do at this point is to supplement them with nutrients! Most seed starting mixes have very little nutrition if any at all. We suggest using ¼ to ½ strength liquid fish/seaweed fertilizer every other watering for your seedlings to be at their happiest!
Using a soilless seed starting mix to start seeds is very important. Soilless seed starting mix is light, fluffy, and perfect for your seedlings to grow strong, sturdy roots! Garden soil or potting soil is often far too heavy and lacking in drainage, making it hard on the delicate root systems of the young seedlings.
What are your favorite tips and tricks for seed starting?
15 Responses
Vanessa
February 10, 2020
This was helpful in that I believe I need to fertilize, going by the suggestions. I see the person writing this has been gardening for 20 years. That’s commendable! I have been gardening for 45 years—-still learning! I used to be able to start my seeds in my growing medium and not worry, not any more. The new mediums out there just don’t have the nutrients my old one did. At least that’s how it seems to me. Thanks for the article. It was helpful.
Sara Clay
February 10, 2020
At first sign of damping off, water from top with chamomile even if they don’t need water, drain well and do not rewater til soil is on the dry side. Has worked for me to save most of the damping off seedlings!
I start all my seeds in pure compost from my piles, screened through 1/4” hardware cloth, with a sprinkle of bone meal mixed in. If snow melt here in Vermont is late and even raised beds are too wet to work, they get weekly fish emulsion to keep them vigorously growing, or even potting up for those that like warm soil. So I take care not to start seed too early since younger vigorous transplants do better than older root-bound ones.
No need to buy that expensive sterile nutrient-less starting mix that dries out so fast if you have compost that stays so nicely moist and is forgiving if neglected for a day or three. I bring in several 5 gallon buckets full each fall and store in cool cellar with an old dinner plate on top so it has a bit of air around the edges and stays damp but not moldy. The worms (and no doubt the beneficial bacteria and fungi) are still living when I start my seeds in spring. I put the worms in kitchen compost and dump them into the outdoor pile.
Only had damping off 2 years out of almost 30 here, and the chamomile tea did the trick for most of the seedlings.
Linda Paulson
February 10, 2020
Potting soil also causes little flying bugs similar to fruit flys
Wilma Crumling
February 10, 2020
Excited about gardening this year!
Frank Heiberger
February 10, 2020
The only time you water from the top is when you water the seeds in initially. From then on, whether seeds have sprouted or not, water from the bottom to draw the roots down and create strong root systems It’s time to water when you lift a pot or six-pack and the tray beneath it is no longer damp. Add only enough water to fill the tray about 1/4 inch.
Susan Hatfield
February 10, 2020
Thanks, great information. Love the music!
Amy
February 10, 2020
Thanks for the info. Just in time. Also love you choice of music! But really thank you for the information.
Katie Pence
February 10, 2020
To deter mice and birds I sprinkle chili powder or cayenne pepper on the flats. Doesn’t seem to affect the plants. But does help if your seedlings are getting g eaten.
Kath Anderson
February 10, 2020
What a great article to read on this February morning in Minnesota! Will be starting seeds when we get back from a week in Florida. No new information for me but lots of good reminders. I LOVED the Spotify playlist, you guys rock!
Ruth Flescher
February 10, 2020
My favorite watering tool for starting seeds is a kitchen baster. It lets you put the water exactly where you want it (on the soil, not the seedlings) and you can control the pressure to apply the water very gently so seedlings aren’t knocked over and soil and seeds aren’t washed out of place.
Julie Wolf
February 10, 2020
I start tomato seedlings by planting the seeds in small pots,moistening the soil well,covering with plastic wrap, and putting on top of the refrigerator. The heat from the refrigerator makes the seeds germinate quickly, and I then move them to a sunny window.
Jana
February 10, 2020
Very helpful tips! Thanks for this article.
Thomas F Witwicki
February 10, 2020
This is an excellent article. In my 40 plus years of gardening, I have experienced just about every problem you mention. I have found that the use of heat mats is critical for the proper germination of some heat loving plants. Always consult the optimal germination temperature range for the vegetable or flower to be germinated. Using a 20 row seeder with a humidity dome as you have pictured can optimize the space on a heat mat, but be careful that you don’t mix seeds that require different germination temperatures or germination times, because the humidity dome needs to come off once you see the seeds start to germinate.
Bob
February 10, 2020
Cinnamon sprinkled on the soil around seedlings can prevent damping off (plant rotting at soil level).
Richard Mammel
February 10, 2020
As always, you wonderful folks hatch such good stuff. This straightforward list, the hints, and very helpful pics in all compress a lot of instruction into a nearly Spartan space. This is a good presentation for even veteran gardeners, well beyond novices, being at the least alerts as to how problems may occur and how to remedy those that may present themselves. Thanks as always to you!
Too much light. Seedlings need a ‘rest’ period, which is why it is suggested to only provide 14-16 hours of light.
Possible Causes
Vanessa
February 10, 2020
This was helpful in that I believe I need to fertilize, going by the suggestions. I see the person writing this has been gardening for 20 years. That’s commendable! I have been gardening for 45 years—-still learning! I used to be able to start my seeds in my growing medium and not worry, not any more. The new mediums out there just don’t have the nutrients my old one did. At least that’s how it seems to me. Thanks for the article. It was helpful.