You want to wait until they have four to six true leaves before you start hardening them off. The ones in your picture are just getting started and are completely unprepared for the outdoors right now. Give them another couple of weeks until the root system actually fills out the cell so the plug holds together when you pop it out. If you move them too early they just get beat to hell by the wind and suffer severe transplant shock.
Those shriveled leaves are almost definitely from uneven moisture. The cardboard seed trays you are using are notorious for wicking water away from the soil and drying out incredibly fast. Your soil mix also looks pretty woody and chunky which makes it hard for tiny seedling roots to find consistent water. They probably just dried out and fried. Keep a very close eye on the moisture levels and water the tray from the bottom if you can.
If you keep losing seedlings or notice the stems getting skinny and pinching at the soil line you might be dealing with damping off. You can run a photo through the Agrio app if things keep going sideways. It is a solid second set of eyes for catching early fungal issues or watering problems before they wipe out a whole tray. Just drop your grow lights a bit closer so they do not stretch and keep that soil moisture consistent.
gothamz
They really haven’t established themselves yet. What zone are you in?
Lemortheureux
If its above 0C you can put them outside in dappled shade to harden
jh937hfiu3hrhv9
Do not let broccoli get rootbound or it will not form a single large head.
sitewolf
kinda go by what you’d see for size at a greenhouse, but the underappreciated thing a lot of people don’t pay attention to is soil temps….anything below mid 60s and they’re not really going to grow much anyway
CMOStly
I give mine about five weeks: one month growing and one week hardening off. Of course, weather can extend this, as it’s doing for me at the moment.
spaetzlechick
I’d recommend not using those cells again for anything other than lettuce. They’re just too small, and even worse when you haven’t filled them all the way up. The bigger the seed the bigger the cell.
Given they are germinated, you can start taking them outside for field trips any day the weather is over 50, or 40 with a cover (but watch out if sunny because they can heat up amazingly fast). Watch your weather for transplanting, if the two week forecast stays upper forties or 50s I’d play them with a fabric row cover.
7 Comments
You want to wait until they have four to six true leaves before you start hardening them off. The ones in your picture are just getting started and are completely unprepared for the outdoors right now. Give them another couple of weeks until the root system actually fills out the cell so the plug holds together when you pop it out. If you move them too early they just get beat to hell by the wind and suffer severe transplant shock.
Those shriveled leaves are almost definitely from uneven moisture. The cardboard seed trays you are using are notorious for wicking water away from the soil and drying out incredibly fast. Your soil mix also looks pretty woody and chunky which makes it hard for tiny seedling roots to find consistent water. They probably just dried out and fried. Keep a very close eye on the moisture levels and water the tray from the bottom if you can.
If you keep losing seedlings or notice the stems getting skinny and pinching at the soil line you might be dealing with damping off. You can run a photo through the Agrio app if things keep going sideways. It is a solid second set of eyes for catching early fungal issues or watering problems before they wipe out a whole tray. Just drop your grow lights a bit closer so they do not stretch and keep that soil moisture consistent.
They really haven’t established themselves yet. What zone are you in?
If its above 0C you can put them outside in dappled shade to harden
Do not let broccoli get rootbound or it will not form a single large head.
kinda go by what you’d see for size at a greenhouse, but the underappreciated thing a lot of people don’t pay attention to is soil temps….anything below mid 60s and they’re not really going to grow much anyway
I give mine about five weeks: one month growing and one week hardening off. Of course, weather can extend this, as it’s doing for me at the moment.
I’d recommend not using those cells again for anything other than lettuce. They’re just too small, and even worse when you haven’t filled them all the way up. The bigger the seed the bigger the cell.
Given they are germinated, you can start taking them outside for field trips any day the weather is over 50, or 40 with a cover (but watch out if sunny because they can heat up amazingly fast). Watch your weather for transplanting, if the two week forecast stays upper forties or 50s I’d play them with a fabric row cover.