Watering when growing under lights

10 years ago

last modified: 10 years ago

Only started growing plumerias last spring and since then have accumulated about fifteen cuttings, three plants and thirty one-month old seedlings. All are grown indoors under lights. I fall asleep at night reading the Plumeria threads here, back several years and beyond. But much of my care is still a shot in the dark.

How do I water plants indoors? Been assuming that it's a different game than with containers outside, but might be dead wrong. You may say I should post in "Growing Under Lights" but felt that since plumerias are somewhat unique with their water requirements, I'd try here first.

I don't water my cuttings until 6 inch leaves have formed, an exception would be to give a spare dose if there is some shriveling. But I'm lost with water requirements after that point. Once my cuttings' leaves reach the magic length I water 3/4 to 1 cup when the meter measures the lowest of "dry". That gets the meter up to about 3/4 of the way to "wet"; then the meter reaches the low mark in about a week. Water obviously never drains from the pots after watering that amount. Maybe I am too paranoid about overwatering? But have no idea how much or HOW to water. Should I be watering enough to run water through containers, or sparingly as I've been doing?

Distilled water? Rain water? Tap water?

And the seedlings....they are all a few weeks to a month old. I keep them relatively moist but not wet. Is that OK? When do the seedlings "dry" requirements begin?

It may be that because there are so few inside only plumerians that I may not get an answer. But most of you should have a heck of a lot better idea than I do.

Thanks once again.

Nancy

PS. The containers' soil is 1/2 Miracle Gro with 1/2 perlite. But about 20% are 1/3 pinebark fines, 1/3 Miracle Gro and 1/3 perlite with the idea of possibly moving to gritty mix at some point.

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Comments (3)

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the_first_kms2
10 years ago
I think you are doing the right thing with Seedlings. I like using rainwater whenever possible. It just seems to me (and others in Austin/SA area) rainwater very rarely causes rot. It could be we have a mild climate and its rare we are wet AND cold.

Hopefully one of the regular grow light users will provide their input as my experience is entirely natural light. So I will gladly defer to them on that item.

I would recommend that watering be based upon the number of leaves each plant has and the amount of warmth provided. Unfortunately there isn't going to be a "right" answer for watering since conditions will vary. Perhaps I can recommend a process for you to start with and then adapt to your local conditions based on how the plants respond. If they are 1 gallon and have a full head of leaves and are in a greenhouse with temps 70-80 degrees as an example then I would water over winter about 1 cup every 10 days to start. If I saw the bottom most leaves yellow but the soil was dry by day 8 or 9 then I would increase to every 7 days. Conversely if you find the soil still moist and leaves yellowing then I would reduce the watering by half (1 cup every 15 days or 1/2 cup every 10). If your GH is cooler than 60degrees then i would water less than 1 cup per month. If your plants have lost their leaves then I would provide none to 1/2 a cup or so in a month.

Best advice is to water a measured amount and watch for the results then
adjust and watch for results until you find a what works for each
plant.
elucas101
10 years ago
Your mix sounds good for plumies and should drain really well which will help your pots dry out much better than a heavy mix so good job on that!

After you work with them for a while you should begin to get the feel for the weight of your containers to give you a very good indication as to whether the pots are still really wet. Inserting a chopstick down in the soil is also a great way to tell if they're wet deeper than a finger poke will go. Like Kms said, it's impossible to give an exact amount because it varies so you have to begin to use your intuition, by weight, by how the leaves look, etc.

When I root cuttings I root them in a water bottle or Gatorade bottle with the top cut off so I can see when the roots develop - once it has roots I water it until water runs out of the bottom and all the soil is saturated & then I can also see when the soil looks pretty dry and it then basically gets watered like any other plumeria - water thoroughly and then let get fairly dry and repeat.

Same with seedlings - I would usually mist them twice a day just so they didn't dry out completely and then when the bulk of the soil they're in is getting dry I water thoroughly. Once they are big enough to be potted up out of my seed starter I usually stop the misting. I water them pretty much just like the adult plumerias and the cuttings.

I would at least sometimes water until the water runs out of the container to flush accumulated salts in the soil that remain from fertilizer.

Keeping your warmth up indoors is key, and the lights will help too. If you have a fan going that would be even better to help dry the soil a bit and help deter spider mites a bit.

I think you'll find that as long as they don't stay really wet and cold they are actually pretty resilient and easy to grow. Please keep us updated on your progress!
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Nancy
Original Author
10 years ago
last modified: 10 years ago
Thanks Elucas. Have most of your recommendations in line now. Have had two fans going since I started accumulating, and doing preventive neem oil treatments every two weeks. I think what you and K are saying is that I need time to get to know my plants and adjust watering schedule according to that. Thanks for addressing when to water till it runs out the bottom too- think I'll try with at least some of them in a month or so. Biggest fear of doing that is waking up and seeing them all in a mushy slump the next morning. I'm going to start doing the screen and wick thing when transplanting seedlings and doing cuttings from now on.

Thanks to you and K for your reassurance. Springtime comes a new greenhouse and will have to get used to a new regimen then.

K, I got a bid yesterday for a permanent greenhouse- it involves taking some trees down which will be harder to convince my husband to do than spending the $. It wasn't as costly as I anticipated. But if I end up settling for the Amazon cheapie one I showed you, that's ok temporarily. Whenever you get yours up eager to hear what your thoughts are.

Thanks to both of you again.

Nancy