Seed Starting, Part 2: What To Do After Germination
Check out our latest tutorial video below about what to do with your seeds after they have started to germinate (when they’ve started to grow). Then keep scrolling for some tips and links to help you out! If you missed the first video on How to Successfully Start Seeds, be sure to check that out first, as it will get you started on growing a great garden – whatever your skill level.
>> Download: When to Start Seeds Indoors
We also have for you an easy-to-follow written guide on when to start what.
Your seedlings will need light, but they also need periods of rest (darkness) too. A good rule of thumb is to turn the grow lamps off when you go to sleep, and turn them on when you wake up (or use a timer). Read all about different types of grow lights here.
Seedlings need blue night and red light. Sunlight includes both. Red light stimulates the growth of leaves and flowers. Blue light regulates the growth/size of plants.
Don’t use incandescent light, use fluorescent. Full spectrum bulbs include both red and the blue light, or you could use one warm (red) light and one cool (blue) light.
The grow lamp should be about 2-4 inches above the seedlings, so adjustable lights are helpful. You can find the Tabletop Garden Starter® Grow Light Kit shown in the video (and in the photo above) from Gardener’s Supply.
Be sure you clean the lightbulbs, as dust and dirt can cut down on the amount of light emitted.
Hold your hand above the seedlings. If it feels warm, the light is too close.
Water from below, not above, to ensure that you don’t squash the seedlings. Make sure your seedlings aren’t sitting in water, or you’ll have issues with rotting, fungus, and soil gnats.
Your seedlings might need to be watered if:
- The soil looks lighter
- The soil pulls away from the edge of the cell
Self-watering seed starting kits use capillary mats, but be sure to check the water levels on those as well.
Seedlings need food when they get their “true leaves.” The first leaves that come up are typically embryonic leaves from the cotyledon (part of the seed) so look for the second (“true”) leaves to appear before you start fertilizing. Use fertilizer at a weaker strength than you would for full-sized plants.
There are several different options for how to fertilize your seedlings. The ones shown in the video are Sustane Compost Tea Bags and Alaska Fish Fertilizer 5-1-1 Concentrate 1 Quart
Your seedlings will be healthier and more sturdy if air is flowing above and around them. A fan can be used – we recommend putting it on a timer, just like your grow lights.
5. Room to Grow
Most people put more seeds than are needed in each cell, so you’ll need to either (carefully) pull out the weaker ones from each cell, leaving one healthy one, or cut them off at the base. Monica demonstrates both methods in the video.
Be sure to check your seed packet to see how long it should take your seeds to germinate. If no seedling has appeared by a few days later than expected, sow some new seeds.
6. A Bigger Pot (optional)
It’s not needed, but if you’re not moving your seedlings into a garden for several weeks, you might want to transfer them to a larger container. If your plant is about two times the size of the container it’s in, or you can start to see roots below the cell, you might want to move it to give it more room to develop, access to more nutrients and more moisture, and the roots will have more space to grow. A 3 to 4″ pot should work well.
If you’re reusing pots, be sure you wash them well before you use them.
You can also use Eco-friendly Seed-starter Cowpots, which you eventually plant into the ground, adding nutrients and organic matter to the soil.
Use a potting mix (such as the Organic Potting Mix, 20 Qts. from Gardener’s Supply) when you transplant your seedlings. Make sure that it is adequately moist – if you grab a handful and squeeze it, it should hold together, but if you move your hand, it should fall apart (see the video at about the 23 minute mark for a demonstration of this).
When transplanting, never grab a seedling by the stem, or you could damage or kill the plant. It’s better to try to push it up from the bottom of the cell, and try to take it out in one piece.
After transplanting, be sure to still water your seedling from below.
Important note: when you do move your seedlings outside, you need to do something called “hardening off,” which is slowly exposing them to the conditions they will encounter in your garden.
Be sure to label your seedlings so you know what they are!
Ones shown in the video include ones similar to these seed markers. The garden stakes from Botanical Interests are currently sold out. One of our YouTube viewers also suggested using venetian blinds as labels. We thought that was a great idea!
What are you growing from seed this spring? Let us know in the comments below! And don’t forget to subscribe to our YouTube Channel.
Disclaimer – All opinions expressed here are those of the author based on personal experience using the product.
Please note that the Amazon and Gardener’s Supply links (and only the Amazon and Gardener’s Supply links) above are affiliate links. Should you choose to purchase products through these links, GPReview will make a small commission (at no extra cost to you) that helps to support this website and our gardening product reviews. Thank you!
About The Author
Sarah, originally from Wisconsin, prefers to be outdoors whenever possible. She has been known to high-five trees on hikes, tests the limits of her balance on kayaks, and is re-discovering a love of cycling. She works behind-the-scenes at the Gardening Products Review, located in sunny Tucson, Arizona.
Grow Guide 2: Seedlings After Germination
In the first episode of Sista Mary’s Grow Guide, we’ve seen the germination of her Amsterdam Genetics Skyrocket seeds. Now, as their roots dig into the soil, we witness these seedlings take their first baby steps towards full cannabis maturity.
Grow Guide 2: On With The Seedlings!
We pick up the Growing Blog from were we left off: germination. As you will recall, Sista Mary decided to use kitchen towel for her seeds to germinate. Once light and water had worked their magic, she planted the seedlings into flowerpots with regular garden soil. This was done with great care so as not to damage the emerging taproots. Two weeks later, these fragile little seedlings have changed almost beyond recognition.
To protect the vulnerable baby plant from cold spring nights, pests, and an overdose of May sunshine, the seedlings were kept indoors for a bit. They got a snug spot on the window sill, allowing them to get used to actual sunlight rather than artificial lighting. After all, these Skyrocket plants are meant to be outdoor crops, so a go-between in the form of window seats is a sensible choice. If you don’t have a safe and sunny spot in your home, artificial lighting by fluorescent tubes will do. Just make sure to alternate about 18 hours of light with 6 hours of darkness or your plants may hit the ceiling before you know it. Still, the window sill gives your seedlings a chance to get used to real sunrays, which is a more natural start.
The seed case clings… … and is shed.
Theresa, Hilda, and Caroline: Meet The THC Sistaz!
Of course, after their germination‘s ‘moment of birth’, these three little ladies had to be given proper names. Sista Mary decided on Theresa, Hilda, and Caroline – say hello to the THC Sistaz! Out on the window sill, the little darlings made good progress. The images show how the seed cases were shed, making room for the first tiny leaves to emerge. A few days later, they were followed by the first leaves featuring the tell-tale serrated shape of cannabis foliage.
First leaves reaching for the sun.
Seedlings Child Support Grow Guide
Weed seedlings have an inbuilt drive to grow towards the light. It allows them to catch all the (sun-)light they can to grow taller. At this stage, watch your little ones closely. If the stem grows too fast, it may become unable to support its own weight as the leaves develop. You don’t want your fragile plants to snap at this point, so if you have any doubts, make sure you give the stems some child support. You can do this by carefully using your fingers to prop them up with a small mound of soil. Another option is using a length of wire or a small stick, but these may be tricky to remove later on. Whatever you do, give your girls some guidance if they need it as they take their first baby steps towards maturity.
A mound of soil supports the base of the stem.
Out In The Sunshine
After two weeks of seedling growth, Theresa, Hilda, Caroline were ready for the next big step: time to take the plants outside. Remember that these baby weed plants still have very fragile leaves. For some extra protection, Sista Mary decided to put them in a greenhouse for a smooth transition to outdoor conditions. The spring sunshine is just too bright and intense due to its high amount of UV radiation, which can damage any organism. The greenhouse also shields the plants from rapid temperature drops that can easily occur well into May. Temperatures depend on your location, of course, but in the Netherlands, they can drop below zero in especially cold May nights – killing for these tiny sisters. Better safe than sorry, right?
Starting to look like a proper lady now!
Stick around for the next episode of Sista Mary’s Growing Guide. You’ll find more useful tips and grower’s insights as Theresa, Hilda and Caroline soak up some sunshine outside!