It's my understanding many plant types need at least a few hours of darkness a day to grow properly, so you might want to consider having the lights on a timer rather than 24 hours of light a day. I do 16 hours of light and 8 hours of darkness for my seedlings

I have been growing about 1000 seedlings under lights like you have for years and they do fine. I do all my flowers for cut flower sales this way and I have had it on a timer to save money. Periodically, because of timer failure, they have been on 24 hours but on and off seems to be the best.

That said, I do grow citrus in pots and move them under these lights for the winter. This winter was the first time I left the lights on for the full 24 hours and this winter is also the first time I did not loose one leaf as a result of the lowered light when moving them indoors. The Meyers lemon and the Cocktail grapefruit have flowered and set fruit just fine.

Thank you for the tips selch & ubro!

I've since switched over to a 18 hours on, 6 hours off cycle.

Did some more research last night and read some studies saying tomatoes have a hard time under 24 hours lights without a cooling off period, however some other studies saying 24h light can work for other types of plants.

Good idea to hear lights works well for your citrus ubro. I have a tangerine tree which gets shocked when it comes indoors and loses many leaves, I'll try lights next time!

I have used a setup like yours for several years now with pretty good success. I used to have a timer that turned the lights off at night, but when it stopped working I went to 24-hour lighting (just sheer laziness). Everything grows fine, including tomatoes under continuous light for me. But, it's only for a few weeks or months until it goes outside and has a more realistic lighting cycle.

Violetjune, I am glad to hear 24h light can work. I too was doing it out of laziness, as well of hopes of faster and more compact growth.

I've been going cross-eyed researching about continuous light versus dark periods. The information is confusing.

So far I have on the go: Super Chili Peppers, Tumbler F1 tomatoes, targeting gem marigolds, red geraniums, rockcress, blue fescue, gaillardia grandiflora, gaillardia Torchlight, basil, and some wild rose seedlings.

Some progress photos from today, amazing to see how much has grown:

The tomatoes are even forming flower buds!

First bloom from the indoor seedlings!

Unfortunately I have a an aphid issue and am hand picking daily as I don't want to spray. No matter what I find about 20 each day. They really like living on the marigolds, tomatoes and gaillardia. It is challenging keeping the buggers under control, I wonder if all nursery plants are all sprayed?

This weather is disheartening, I can't wait for it to warm up! Since switching to a 18h on, 6h cycle, the growth of the plants has not been as fast and I am not having to water as much. This might be a good thing as it look like I won't be putting these outside anytime soon. Hopefully it warms up enough to get them in the sunroom to start hardening off.

Those are nice healthy plants, good job.

I would hazard a guess that they spray all nursery plants, they certainly did in the ones I worked in.

I have used a mixture of 2 tbsp. isopropyl alcohol and a few drops dish soap in 2 quarts of water to kill the bugs on some of my indoor plants, maybe using it on one or two plants would be worth trying. Aphids are awful and hard to eradicate. They spray has to cover the whole plant, both upper and lower parts of the leaves and needs to be repeated twice at 3 day intervals to get all the newly hatched eggs.

Thank you so much for the recipe ubro, I think I will give it a try! I may try dipping the plants in the solution.

It appears a contributing factor is the fine dense foliage of the signet marigold 'Tangerine Gem', which they seem to like the most. I've since quarantined these from the rest, here they are today:

It does seem that some plants are aphid magnets. My tomatillos were, two years in a row.

Perhaps this will work. I found a ladybug outdoors and brought it in, here it is feasting on an aphid!

Update, most plants are now moved to sunroom, with tomatoes and peppers left under lights. I've given up on aphids. Last year I had very few things germinate, tried to do everything in the unheated sunroom in April, wasted a lot of seeds, not knowing they need warmed temps to sprout. What a learning curve. The very detailed sowing directions from stokes seeds have been super helpful.

Your plants are looking very healthy and sturdy! Yes, Stokes gives excellent detailed information, though I adjust it somewhat for my shorter growing season and sometimes start seeds a bit earlier than suggested, they also have excellent seed quality.

Prairie, Do you have a heated sunroom? I can never use mine without having to haul the plants indoors overnight. We're still have lows of -8, so plants are stuck in the house for now. As a result I haven't started very many.

+

Hi North 53, my sunroom unheated and uninsulated, and attached to the garage. Maybe a better term is a covered deck? When it's colder, I pull the plants away from the windows and put the window coverings down.

Thank you Twors, this is the first year I've had so many successful seedlings this time of year! I am glad I finally gave basement lights a try. It was worth it to keep myself busy, and more satisfying than buying nursery plants. I enjoying browsing the huge variety of annuals from Stokes. Yes, I really like reading the sowing info geared towards greenhouse growers, it's neat reading about the tricks of the industry. Next year I hope to go with more marigolds, more geraniums, and to try pansies.

They are calling for -4C tonight, although it's supposed to warm up by the end of the week, with night time temps usually about 0-2C. Usually the sunroom is a a few degrees warmer than outside. Does anyone know if it is too early to put the seedlings in the sunroom? In other words, has anyone had bad experiences by exposing their seedling to cold nighttime temps too soon?

Here are the Tumbler tomatoes today, moved to the sunroom. Two plants per pot. The lights helped keep the leaves dense. I can't believe I grew these from seed!

Now for the hardening off process for everything else....

Looking great! The plants look happy

I see you utilize the grey dish pans also. I have a bunch of those and find them so handy for carrying all sorts of things besides plants. I lent one to my DH and doubt he's going to give it back.

Thank you north53! Yes, I love dishpans. I call them bus bins. Years ago I got several at the Real Canadian Wholesale Club in the restaurant equipment supply aisle for about $8, no membership required. Great for washing veggies in, plus they last a lifetime. I use a lot of buckets too, but the rectangle shape of the bus bin is useful as I keep running out of leakproof plant trays. The black plant trays crack so easy.

I got mine from a guy who has a restaurant. He also got me a bunch of trays. At this time of the year they are all in use.

That's a great source north53! Now that I've thought more about it, cafeteria trays may also be perfect. I'll have to keep an eye on kijiji. So far garage sales and thrift stores have been helpful. And red solo cups. Lol I'm somewhat frugal... or rather, I prefer to save my most of dollars for rose plants, seeds, and soil amendments!

Here's another project under the lights:

I did up a couple more trays the other day: marigold 'Crackerjack,' 'Garland Orange,' and 'Queen Sophia' cosmos 'Daydream,' romanseco cauliflower 'Orbit,' kohlrabi 'Winner,' sunflowers 'Orange Sun,' 'Kong,' 'Giant Sungold' and 'Teddy Bear'.

'Orange Sun' germinated within two days at almost 100%, even though the seeds are over a year old.

After this first year of trying indoor lights, I now highly recommend indoor lights to any northern growers.