Tomato seeds not sprouting

[MichaelE]

This is my first time asking a question on the garden forums, so I apologize if it is commonly asked and I have missed it.

Background:
I have started a tray of tomato seeds in both vermiculite (started on 3/24/2020) and in a mix of vermiculite and worm castings on 4/6/2020. I am warming them with a mat, it is under a sunlamp, and I water them daily. These are Cherry Bomb tomatoes that I bought this year with a 99% germination rate.

Problem:
Only one seedling has germinated out of 15 seeds in the packet after multiple weeks. I am obviously doing something terribly wrong. Some of the books that I've read say to start tomatoes with a bottom mat heater and in a loose soil like vermiculite.

What am I doing wrong?

1. Perhaps I am over watering?
2. Perhaps I'm starting with the wrong soil? I have not tested the pH.
3. I only run the heating mat and sunlap via a timer for around 8 hours a day in a basement that gets down below 65 degrees F (but not below freezing), perhaps a lower temperature is stopping the germination process?

Thanks,
Michael

 

[Chuck]

This is my first time asking a question on the garden forums, so I apologize if it is commonly asked and I have missed it.

Background:
I have started a tray of tomato seeds in both vermiculite (started on 3/24/2020) and in a mix of vermiculite and worm castings on 4/6/2020. I am warming them with a mat, it is under a sunlamp, and I water them daily. These are Cherry Bomb tomatoes that I bought this year with a 99% germination rate.

Problem:
Only one seedling has germinated out of 15 seeds in the packet after multiple weeks. I am obviously doing something terribly wrong. Some of the books that I've read say to start tomatoes with a bottom mat heater and in a loose soil like vermiculite.

What am I doing wrong?

1. Perhaps I am over watering?
2. Perhaps I'm starting with the wrong soil? I have not tested the pH.
3. I only run the heating mat and sunlap via a timer for around 8 hours a day in a basement that gets down below 65 degrees F (but not below freezing), perhaps a lower temperature is stopping the germination process?

Thanks,
Michael

View attachment 63420

When starting seeds the most important thing is an adequate sustained heat, and that you do not have. KEEP your seed starting soil at a constant temperature, from 75F - 80F, 24-7. Watering is the second priority. Keep your soil DAMP, not wet. Watering daily is too much and you have probably rotted your seeds. The soil Ph is NOT important for seed germination nor is what kind or type of soil. Many gardeners germinate their seeds on a damp paper towel. Ph and soil type is important after the seeds have sprouted but your single seedling looks fine. What I would say about your soil is that you are not putting enough into the seed starting tray cells. I would start over as I don't think your seeds are still viable after this length of time. Your seeds should sprout within 4-7 days at the suggested temperature. Only seedlings need light. Tomato seeds do not need light to germinate.

 

[MichaelE]

Chuck,
thank you for the quick response. I will turn the heating mat on constantly in the future and will water less frequently. I typically use a spray bottle rather than a watering can as it seems to disturb the soil less.

Regarding the paper towel technique, I have used this technique in the past and still do it for bigger seeds. I don’t like doing it with tomatoes as they are small and fragile. Or maybe I am just big and clumsy.

The germination rate with the paper towel method was probably 50%, but perhaps it would have been better with your suggestion of constant warming.

Thanks again. -M

 

[Chuck]

Chuck,
thank you for the quick response. I will turn the heating mat on constantly in the future and will water less frequently. I typically use a spray bottle rather than a watering can as it seems to disturb the soil less.

Regarding the paper towel technique, I have used this technique in the past and still do it for bigger seeds. I don’t like doing it with tomatoes as they are small and fragile. Or maybe I am just big and clumsy.

The germination rate with the paper towel method was probably 50%, but perhaps it would have been better with your suggestion of constant warming.

Thanks again. -M

The way I start my seeds is to first saturate the potting mix. I then let the cells drain. Then I place a couple of seeds into each cell and pat them down to make good soil contact and sprinkle dry potting mix on top. Next I place Saran Wrap on top of the cells making it as airtight as possible and place the cells on the heating mat. As soon as the seeds sprout I remove the Saran Wrap. Depending on how dry I let the seedlings get I either spray them or usually I place the cells into the sink or bathtub and water them from the bottom up. Most plants would rather be a little too dry than to stay too wet so don't go crazy with the watering. Just keep them slightly damp. Watering from the bottom up usually lasts 7-10 days depending on your soil and how much moisture retention products you have in the mix.

 

[MichaelE]

That is an awesome technique. I am going to try that. I have never heard of the Saran Wrap technique, but it is a great idea. Thanks again, this is enormously helpful.

 

[oneeye]

The way I have found successful for sprouts growing into seedlings, is by watering inside the cell one time, then water the outer cell 5 days later. Plants love it and grow fast because they get oxygen and water. This plant was transplanted last week and watered one time in the middle of the pot, today, five days later i water the outside leaving the inside dry. photos, she's growing fast.

 

[MichaelE]

The way I have found successful for sprouts growing into seedlings, is by watering inside the cell one time, then water the outer cell 5 days later. Plants love it and grow fast because they get oxygen and water. This plant was transplanted last week and watered one time in the middle of the pot, today, five days later i water the outside leaving the inside dry. photos, she's growing fast.

That is a great way to do it. I have not seen that technique before. It is a smart way to give it water and oxygen for sure.

 

[jasper]

It might be the seed quality. I start all my plants in house 70° - 72° until 2 weeks after the sprout. Then set them out side a little for acclamation. The only time I had seed issues is when I get a bad batch of seed. Remember seed will do everything possible the sprout.

 

[MichaelE]

The way I start my seeds is to first saturate the potting mix. I then let the cells drain. Then I place a couple of seeds into each cell and pat them down to make good soil contact and sprinkle dry potting mix on top. Next I place Saran Wrap on top of the cells making it as airtight as possible and place the cells on the heating mat. As soon as the seeds sprout I remove the Saran Wrap. Depending on how dry I let the seedlings get I either spray them or usually I place the cells into the sink or bathtub and water them from the bottom up. Most plants would rather be a little too dry than to stay too wet so don't go crazy with the watering. Just keep them slightly damp. Watering from the bottom up usually lasts 7-10 days depending on your soil and how much moisture retention products you have in the mix.

Chuck (and everyone else that helped out):
I thought I'd give you a quick update. I tried out your technique of Saran Wrap with a constant heating pad, and it worked. After 6 days I've pulled the Saran Wrap off and 9/12 of the seeds germinated into seedlings. While that's a 75% germination rate, it's still early and it is a huge improvement over what I've been doing. Thanks again for the advice.
-Michael

 

[headfullofbees]

I just chuck mine into a seed tray, on top of riddled home made compost, add water, top with a further sprinkling of compost, into a heated propagator, although most homes these days are warm enough, and they're usually up within the week.
Unfortunately. you have rotted your seeds with over-watering, it accounts for half the mistakes made by gardeners & we've all done it, so don't feel bad.
If you give them a good watering when you sow them, they won't need any more water until you prick out and pot on.