Early grow stages are my most challenging times in a grow. I kill or stunt a lot of seedlings. It’s almost embarrassing how inept and clueless I am at this stage.
I’m getting ready in the next week or so to germinate seeds for my 2026 outside grow. I use a damp paper towel enclosed in foil to retain moisture and keep out light. I place this on a seed/heat pad. I usually have a high success rate when germinating.
I place the germinated seeds in solo cups with holes in the bottom for drainage. I usually use soil from my raised bed. These go in 24”x24”x36” tent on the heat pad with the light timer set to whatever the outside sun cycle is - this gets adjusted weekly till hardening. Humidity will in the basement is a fairly stable 55%-60%. Ambient temps tend to be on the cooler side 65-70F. If I heat, I lose air moisture. So it’s a bit of a dance to keep things consistent and it’s confusing to know how much water is to much or to little. In the early years, overwatering was a problem, but I’m better at not drowning stuff now.
Generally seeds break soil after 2-3 days.
Here’s where things seem to slow down, it’ll be 3 weeks before I have a multi digit true leaf on a 3 node plant (2 nodes of single leaf.) This seems really slow. AndRarely when I transplant will I note a really robust root system to start.
Things pick up after a few weeks of being transplanting outside and by the first of June, things are kicking along ok.
Mine should have read 65-80f. I usually have a tiny heater that I cut off with the lights to mimic overnight temps. Maybe it ought to be on its own timer.
I would say not enough light, slightly low temps slow growth but not that much.
I give seedlings 24/0 light for the first few days to keep them warm and stop them getting lanky, then drop to 20/4 for a week then 18/6.
They can also take a lot more PPFD than people tend to advise.
Here’s some of mine at day ~7 and ~14
Shame recs don’t come in candlefoot. I’m sort of joking.
I’m using a Spider Farmer SF1000 2x2 with their dimmer/power supply - they recommend 50-75%, at 24” which is sort of a wide range, I’ll give a run on the higher side this year.
I’m glued in to hearing about this thread. Need much info to be comfortable!
Gardener, composting over 30 yrs, pro landscaper. Know just about zilch growing cannabis. Long time grower brother in law states, “It’s a weed. Put it in the ground, feed it, water it and forget it.” I’m sure that’s not all that is needed but I’m on my first run with sprouted seeds now in my varied mixture of compost, nutrient and amendments.
Started seedling with just enough water over top of seedlings for five days. Then read others are using much more water as soil is all wet (not drowning) so the soil is now wet to just holding together. Lighting is from California Solar 550 with controller. All vegetables there now on bench (no tent or anything else for cannabis later). Have photo and autos. Suggestions very welcome!
I don’t use a meter, I just gave them more light until I saw issues. That’s a Mars FCE-300w in a 2x2.
I start them at 25% (75w) at about 20”, then put it up to about 50% (150w) when I go to 18/6 after a week or so. You can just creep up a bit each day, if you see issues go back down a bit.
Like Slayerscool13 said, another thing to look at over or under watering. Best not to flood soil with seedlings as they need O2 for for root development and they don’t have the roots to drink it quick enough yet, but also don’t let it dry out too much. Both can slow growth a lot.
I posted this in the Lessons Learnt topic, but I’ll share it here as well: Something I tried for the first time was using a wick method to keep seedlings watered. I ran cotton cords from a small “reservoir” (actually a glass of water) to each plant and buried the end about an inch deep. It worked really well at keeping it moist without over watering, and allowed me to leave ‘em alone for a couple days at a time.
