Grow lights, is there too much?

[Ruderunner]

This year we're trying out starting our own seeds for vegetables vs buying from the greenhouse. So far results are very good for our very simple setup.

Setup is a Walmart 36 inch 4 shelf storage rack, assembled upside down so the shelves act as trays to contain water spills. Each shelf has a 24 inch grow light above it. This is in our basement, temperature about 65f. Cheap bagged potting soil and 2 inch biodegradable pots.

Just about everything has sprouted except for one potential pack of seeds that might be duds. We have a pumpkin sprout almost 4 inches tall after only 2 weeks! Everything is on the leggy side which isn't too surprising. I'm going to enclose the rack with cardboard painted white to help concentrate the light and maybe contain a little heat.

In reading about others starting seeds, it seems like most run their lights on a timer. We didn't, the lights have been on 24 7 for 3 weeks or so.

So are we overdoing the lights? Do plants have a circadian rhythm and need the "nighttime "?

I'm aware that some stuff does need downtime to set fruits, like tomatoes. But the plants are mature at that point. Also, we wouldn't be against slowing things down a little bit since it's still several weeks away from planting season.

 

[Chuck]

Seedlings do need darkness for optimum growth. 16 hours per day of light is about the maximum. I turn my lights on when I get up about 5 AM and turn them off about 9 PM when I go to bed. There has been a lot of research on this and the consensus is 16 on 8 off. I have never used actual growlights. I use 4 ft 3000K Soft White fluorescent tubes like one finds in an office. I have it fixed so I can raise and lower the lights and I try to keep the lights about 2 inches above the plant and I never get leggy seedlings. I have found that 4 weeks under my lighting is about maximum for tomatoes and I have to move them outdoors to harden them off for the two weeks before I put them into the ground. I plant seeds 15 Feb and transplant them into the ground 1 April.

 

[Ruderunner]

Ok interesting. I suppose I'll start doing that. Thanks

 

[DirtMechanic]

Ok interesting. I suppose I'll start doing that. Thanks

I have a setup that uses heat mats and lights plugged into a wifi strip. The lights have onboard switches and are on two plugs while the mats are on their own plug. The power strip has plug switches for further control, and the speakers\phone app keep the individual plugs on a timer.

Limited-time deal: Kasa Smart Plug Power Strip HS300, Surge Protector with 6 Individually Controlled Smart Outlets and 3 USB Ports, Works with Alexa & Google Home, No Hub Required , White

 

[Oliver Buckle]

Using a third less electricity has got to be worth it. Mind you, it is probably dearer in England than anywhere else.
I get by with a propagator on an East facing windowsill, then uncover them and put them on the south facing sill as soon as they germinate, when the second leaves come all but the most tender go out to the greenhouse.

 

[Ruderunner]

Considering the other electronics in constant use, these lights are inconsequential.

DM, little fancy for our needs, I'll just flip the switch on the power strip.

 

[DirtMechanic]

Considering the other electronics in constant use, these lights are inconsequential.

DM, little fancy for our needs, I'll just flip the switch on the power strip.

All good...I understand. My dogs get them up to pee every 4-6 hours and I have not figured out how Alexa can help me with that. Still, its one less thing to deal with right?

 

[Ruderunner]

We have 3 dogs, I'm well aware of pee o'clock!

 

[Oliver Buckle]

You could try a kennel and a chain

That reminds me of a story I wrote

 

[Ruderunner]

Our dogs are "free range " mostly on the couch or bed. But they go outside and run in the yard .

The pup loves to help in the garden but still can't tell weeds from plants. I lost a whole potato crop one year. And she likes Brussels sprout stalks. Pulled those out and used them as chew bones!

Already caught her digging in the garlic and beets this year. Stopped and picked up materials for a proper puppy proof fence the other day.

 

[Ruderunner]

Well, now I have a problem. Sorta.

Without the lights running constantly, my grow cabinet appears to be getting a little chilly. Tomato stems and cabbage sprouts are turning purple. I'll have to figure out a heat source, I don't think mats will cooperate with the current design.

Otoh, many plants have outgrown the starter pots, spent time transplanting to Solo cups yesterday. Not ideal but was handy.

 

[DirtMechanic]

Well, now I have a problem. Sorta.

Without the lights running constantly, my grow cabinet appears to be getting a little chilly. Tomato stems and cabbage sprouts are turning purple. I'll have to figure out a heat source, I don't think mats will cooperate with the current design.

Otoh, many plants have outgrown the starter pots, spent time transplanting to Solo cups yesterday. Not ideal but was handy.

Have you seen the double solo cup method? Holes in the first allowing roots additional room? I have not tried it, and wonder how to get them loose but I like the idea of not impeding root growth to prevent stunting.

So everything is growing well but purple tomato? That is an odd context. Are you sure its not nutrition? Seed mix is praised for drainage and sterility for emergence purposes.

 

[Ruderunner]

Haven't seen the double cup method. Though I sorta did it. I started in the 2" biodegradable pots and for some I put that into the solo cup.

Hopefully this will give the roots enough room until I can get them outdoors.

In another recent thread, it was mentioned that purplish stems indicate too cool. Could be nutrition related but only tomato and cabbage sprouts show it currently.

It does seem cooler without full time lights. Didn't help that we had no power for most of a day this weekend.

 

[Chuck]

Have you seen the double solo cup method? Holes in the first allowing roots additional room? I have not tried it, and wonder how to get them loose but I like the idea of not impeding root growth to prevent stunting.

So everything is growing well but purple tomato? That is an odd context. Are you sure its not nutrition? Seed mix is praised for drainage and sterility for emergence purposes.

If the leaves were also purple it would be nutrition (phosphorus) but if just the stems they are a little too cool. And some varieties can withstand cooler temps than others. About all the purple stems will do is slow the growth somewhat but when placed outside in the sun they will lose the purple color and resume their normal growth.

 

[Chuck]

Well, now I have a problem. Sorta.

Without the lights running constantly, my grow cabinet appears to be getting a little chilly. Tomato stems and cabbage sprouts are turning purple. I'll have to figure out a heat source, I don't think mats will cooperate with the current design.

Otoh, many plants have outgrown the starter pots, spent time transplanting to Solo cups yesterday. Not ideal but was handy.

I bought one of those electric oil fill heaters with 3 heat settings. I keep it on the low setting and it uses very little electricty. It works perfect for my seedlings. I got the cheapest I could find and it has lasted IIRC 4 years now. I put it underneath where the planting cells are and with heating mats my tomato seeds germinate usually on the fifth day. Peppers on about the 8th day.