Starting Seeds
Feb. 18th, 2026 08:49 am![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
ranunculusI am NOT an expert in seed starting, but I have learned some stuff over the last 5 years.
Starting seeds isn't complicated. Most seeds will start with no fuss any time the soil is warm enough for them to germinate. It is definitely WAY cheaper to start seeds than buy plants.
I have started plants in plain old potting soil, but it isn't ideal for a bunch of reasons. These days I'm starting with a seed soil mix of about 50/50 pearlite and fine coconut coir, or perhaps a little heavier on the coir side. The pearlite keeps things light, the coconut coir holds moisture in the mix. Commercial seed mixes are so pearlite heavy that they barely hold any water, certainly not enough for me in my dry climate. Regular spraying with a spray bottle has kept things just about damp enough for germination, but that is WAY too much work! I could, and have, started seeds in pure coconut coir, but it is a tad too wet for me to love. The really good thing about a very light seed starting mix that isn't dirt and it doesn't mold easily. If you have problems with your seeds "damping off" a lighter mix along with keeping things sterile should help.
The soil goes into seed trays with clear plastic tops OR into big open square trays depending on the kind and number of seeds I'm starting.
In this picture the tray on the right is filled with my dahlia seeds which are germinating ok. They didn't germinate fast because this is pure commercial "seed mix" and it was too dry for them at first, despite having been soaked for a day in advance. Square trays like this one are great if you are germinating a whole lot of seeds for a big bed (big is relative, don't laughunicornduke :). They are also nice because you can spread the seeds out so there is less root damage as you transplant. On the downside they are very slightly raised so wicking matting might not make good contact. Johnnie's carries the trays https://www.johnnyseeds.com/tools-supplies/seed-starting-supplies/pots/plastic-pots/polypro-5x5-insert-pots-black-8-count-6358.html
The tray on the left with the clear top is nice for tiny seeds as the tops hold in the moisture and they do a tiny "greenhouse" effect. You could certainly do this with a plastic bag or other makeshift clear lid, but the seed trays keep the process compact. In addition this tray is sitting on a water reservoir.
From left to right: water reservoir, seed tray, platform (up on tiny legs) and wicking material. The wicking material hangs over the edge of the platform, wicks up water and delivers it to the bottom of the seed tray. Works great and solves the problem of wet/dry cycles with the little plants. This system is called "Grow Ease", and is my favorite of the available "systems". Recommended if you decide to step up from starting seeds in yoghurt containers or the like. I like the 12 cell containers, not the bigger ones. That way I can plant fast germinating plants, like broccoli and peas in one, and slow germinating plants like peppers in another.
Johnny's sells really nice plant and seed trays for moving your potted plants around. The polypro ones are very sturdy and I like the colors but they don't have drainage, which is fine as long as the plants never sit in water. https://www.johnnyseeds.com/tools-supplies/seed-starting-supplies/trays-domes-and-flats/support-trays/polypro-endurance-deep-tray-no-holes-blue-4-count-6344.html ;
Most seeds germinate readily at room temperature. A few need extra warmth. I have to use a heat mat for pepper seeds. The heat mat adds about 10 degrees to the soil temp. Peppers are SLOW and if the soil isn't toasty warm they will faff around till they rot.
Once the seeds actually germinate I pull the lids so things don't mold.
Seed mix doesn't need or really want nutrition as it can promote mold and seeds don't need it for germination. Getting the seedlings transplanted into soil fairly quick is essential for growth and good health. When my seedlings are a week or two old, just long enough to have formed a good root, I transplant into individual plugs OR plant several in a 4" pot to grow on. Seedlings that are not transplanted will simply sit and sulk once the seed energy is used up. Once they are transplanted seedlings need both nutrition and a good microbiome around their roots. Commercial potting soil is notorious for having poor microbiomes no matter how much they boast about their soil, which is where compost from your compost pile comes in handy. Experts say that one handful of good live compost can inoculate quite a lot of soil. Those microbes get around!
Helmet Head Helmet head is when the seed coating is too dry and hard for the seedling to push it off their leaves. If seed coatings don't drop off , use a spray bottle to wet them down. Wait for 5 minutes or so and very, very gently see if the seed coating has softened enough to pull off. If it still won't move re-wet it and wait some more. The key word is "gentle". Don't pull with any force or you will tear the leaves off and kill the plant.
The center seedling has a helmet. I've sprayed it down and dahlia seed coatings are very soft so this seedling will probably push it off just fine by itself.
If you are vigilant about keeping seedlings moist as they unfurl or if you regularly removing stuck coatings; plants will be fine. If the seedlings stay helmeted for more than a couple of days it will kill the seedling by depriving it of light. I live in a very dry climate so this is a reoccurring issue for me.
Supplies: I buy ground up, compressed coconut coir on the internet as there are no good local sources here. It is pretty cheap and a little goes a long way if you buy the compressed bricks. Pearlite is sometimes available at good garden centers and easily available on the internet.
Other supplies that are nice.
On the right is a widger, a metal tool that helps scoop seedlings out of a seed starter tray. https://www.johnnyseeds.com/search/?q=widger&search-button=&lang=en_US ; They really work. A "dibbler" is a round object to make a hole in your soil so you can plant. A pencil, pen, stick, finger all work as dibblers. I use two separate dibblers. One is a pointed stick about 3/4" in diameter with marks for depth. Another is the broken tine of a manure fork (red, cleaned up). There are multitudes of dibbler designs out there. Eventually I may get one with a metal tip that gets wider than my current one does. I use my wood dibbler to make most of my holes, especially if the seedling has good roots, and then the broken tine to move dirt around to fill in around the little plant. One last thing that helps is a flat block of material that you can slightly compact your seed mix so it is level and the seeds will make good contact with the dirt when you sow them.
Of course you do need to mark your seeds so you know what you planted. Wood stakes are highly compostable. Almost too compostable, but they do a great job if they aren't asked to last for months. https://www.johnnyseeds.com/tools-supplies/labeling-supplies/pot-labels-1000-count-9232.html ; I first ordered smaller lots than the 1,000 box and that was a mistake. To write on the tags, the garden markers really are worth it, they outlast and outperform sharpies by a lot. https://www.johnnyseeds.com/tools-supplies/labeling-supplies/weatherproof-marking-pens-9350.html
Starting seeds isn't complicated. Most seeds will start with no fuss any time the soil is warm enough for them to germinate. It is definitely WAY cheaper to start seeds than buy plants.
I have started plants in plain old potting soil, but it isn't ideal for a bunch of reasons. These days I'm starting with a seed soil mix of about 50/50 pearlite and fine coconut coir, or perhaps a little heavier on the coir side. The pearlite keeps things light, the coconut coir holds moisture in the mix. Commercial seed mixes are so pearlite heavy that they barely hold any water, certainly not enough for me in my dry climate. Regular spraying with a spray bottle has kept things just about damp enough for germination, but that is WAY too much work! I could, and have, started seeds in pure coconut coir, but it is a tad too wet for me to love. The really good thing about a very light seed starting mix that isn't dirt and it doesn't mold easily. If you have problems with your seeds "damping off" a lighter mix along with keeping things sterile should help.
The soil goes into seed trays with clear plastic tops OR into big open square trays depending on the kind and number of seeds I'm starting.
In this picture the tray on the right is filled with my dahlia seeds which are germinating ok. They didn't germinate fast because this is pure commercial "seed mix" and it was too dry for them at first, despite having been soaked for a day in advance. Square trays like this one are great if you are germinating a whole lot of seeds for a big bed (big is relative, don't laugh
unicornduke :). They are also nice because you can spread the seeds out so there is less root damage as you transplant. On the downside they are very slightly raised so wicking matting might not make good contact. Johnnie's carries the trays https://www.johnnyseeds.com/tools-supplies/seed-starting-supplies/pots/plastic-pots/polypro-5x5-insert-pots-black-8-count-6358.htmlThe tray on the left with the clear top is nice for tiny seeds as the tops hold in the moisture and they do a tiny "greenhouse" effect. You could certainly do this with a plastic bag or other makeshift clear lid, but the seed trays keep the process compact. In addition this tray is sitting on a water reservoir.
From left to right: water reservoir, seed tray, platform (up on tiny legs) and wicking material. The wicking material hangs over the edge of the platform, wicks up water and delivers it to the bottom of the seed tray. Works great and solves the problem of wet/dry cycles with the little plants. This system is called "Grow Ease", and is my favorite of the available "systems". Recommended if you decide to step up from starting seeds in yoghurt containers or the like. I like the 12 cell containers, not the bigger ones. That way I can plant fast germinating plants, like broccoli and peas in one, and slow germinating plants like peppers in another.
Johnny's sells really nice plant and seed trays for moving your potted plants around. The polypro ones are very sturdy and I like the colors but they don't have drainage, which is fine as long as the plants never sit in water. https://www.johnnyseeds.com/tools-supplies/seed-starting-supplies/trays-domes-and-flats/support-trays/polypro-endurance-deep-tray-no-holes-blue-4-count-6344.html ;
Most seeds germinate readily at room temperature. A few need extra warmth. I have to use a heat mat for pepper seeds. The heat mat adds about 10 degrees to the soil temp. Peppers are SLOW and if the soil isn't toasty warm they will faff around till they rot.
Once the seeds actually germinate I pull the lids so things don't mold.
Seed mix doesn't need or really want nutrition as it can promote mold and seeds don't need it for germination. Getting the seedlings transplanted into soil fairly quick is essential for growth and good health. When my seedlings are a week or two old, just long enough to have formed a good root, I transplant into individual plugs OR plant several in a 4" pot to grow on. Seedlings that are not transplanted will simply sit and sulk once the seed energy is used up. Once they are transplanted seedlings need both nutrition and a good microbiome around their roots. Commercial potting soil is notorious for having poor microbiomes no matter how much they boast about their soil, which is where compost from your compost pile comes in handy. Experts say that one handful of good live compost can inoculate quite a lot of soil. Those microbes get around!
Helmet Head Helmet head is when the seed coating is too dry and hard for the seedling to push it off their leaves. If seed coatings don't drop off , use a spray bottle to wet them down. Wait for 5 minutes or so and very, very gently see if the seed coating has softened enough to pull off. If it still won't move re-wet it and wait some more. The key word is "gentle". Don't pull with any force or you will tear the leaves off and kill the plant.
The center seedling has a helmet. I've sprayed it down and dahlia seed coatings are very soft so this seedling will probably push it off just fine by itself.
If you are vigilant about keeping seedlings moist as they unfurl or if you regularly removing stuck coatings; plants will be fine. If the seedlings stay helmeted for more than a couple of days it will kill the seedling by depriving it of light. I live in a very dry climate so this is a reoccurring issue for me.
Supplies: I buy ground up, compressed coconut coir on the internet as there are no good local sources here. It is pretty cheap and a little goes a long way if you buy the compressed bricks. Pearlite is sometimes available at good garden centers and easily available on the internet.
Other supplies that are nice.
On the right is a widger, a metal tool that helps scoop seedlings out of a seed starter tray. https://www.johnnyseeds.com/search/?q=widger&search-button=&lang=en_US ; They really work. A "dibbler" is a round object to make a hole in your soil so you can plant. A pencil, pen, stick, finger all work as dibblers. I use two separate dibblers. One is a pointed stick about 3/4" in diameter with marks for depth. Another is the broken tine of a manure fork (red, cleaned up). There are multitudes of dibbler designs out there. Eventually I may get one with a metal tip that gets wider than my current one does. I use my wood dibbler to make most of my holes, especially if the seedling has good roots, and then the broken tine to move dirt around to fill in around the little plant. One last thing that helps is a flat block of material that you can slightly compact your seed mix so it is level and the seeds will make good contact with the dirt when you sow them.
Of course you do need to mark your seeds so you know what you planted. Wood stakes are highly compostable. Almost too compostable, but they do a great job if they aren't asked to last for months. https://www.johnnyseeds.com/tools-supplies/labeling-supplies/pot-labels-1000-count-9232.html ; I first ordered smaller lots than the 1,000 box and that was a mistake. To write on the tags, the garden markers really are worth it, they outlast and outperform sharpies by a lot. https://www.johnnyseeds.com/tools-supplies/labeling-supplies/weatherproof-marking-pens-9350.html
no subject
Date: 2026-02-19 04:51 am (UTC)Yes, Sharpies evaporate in sunlight! I remember being startled when I first realized. Good to know that there's a good alternative.
no subject
Date: 2026-02-19 04:59 am (UTC)no subject
Date: 2026-02-19 05:05 am (UTC)no subject
Date: 2026-02-19 05:59 am (UTC)no subject
Date: 2026-02-19 09:07 am (UTC)Oh thank you for reminding me. I've got some basil that I need to plant before I forget and hold on to the seed packet for years. I'm going to go for potting soil because it's all I've got, however.
no subject
Date: 2026-02-19 05:46 pm (UTC)no subject
Date: 2026-02-20 12:29 pm (UTC)This is probably why my garden doesn't thrive - I garden according to when I remember things and when I have energy rather than when it's best. But I've done basil around this time of year before and it was okay. They're on a warm window-ledge.
no subject
Date: 2026-02-19 08:09 pm (UTC)no subject
Date: 2026-02-19 11:55 pm (UTC)I really fumbled around for a couple of years with seeds because I didn't understand a bunch of the stuff I just wrote up.
One thing I didn't add was: always water your transplants right after planting. Even if the soil is quite wet, watering helps settle the roots and helps remove air pockets around them. This goes from the tiniest seedling to transplanting a tree.
Another thing I didn't say, and should have: never touch a seedling's stem. Always handle it by a leaf. If a leaf breaks or tears, it will grow back but if you crush or break a delicate little stem the plant is dead.
no subject
Date: 2026-02-23 11:23 am (UTC)It does add some weed seeds, but the intended seeds also grow well.
no subject
Date: 2026-02-23 06:04 pm (UTC)A couple of years ago my seed mix had compost in it. That was a mistake as the compost was especially weedy that year. At least this year, with a seed free starting mix I'm sure that what I'm growing on is a seed I wanted to grow! Weeding later on is fine.