Indoor Basil

Discussion in 'Gardening' started by illsstep, Sep 27, 2016.


    illsstep Member

    I'm starting a crop of basil indoors from seed to see how well I can control the heat, humidity, etc. in the grow area I set up.

    I don't grow weed myself, but I'm very interested in gardening under artificial light (mostly as a way to keep growing during the winter months). I learned quickly that marijuana growers are the ones to learn from if you want to know about growing under lights; most other gardening communities use lights for seed starting and little else. That's partly why I'm posting this here - I figured this community might appreciate it more.

    The grow area:


    Since I don't have to worry about odors, and this is in a main room of my apartment, I went with a more open design rather than a tent. It is 3'x3' and uses a Sun System 315 LEC. Ventilation was a bit trickier due to the open design; I settled on a couple window fans drawing air up out of the growing area (and deflected away at an angle) as well as an intake/oscillating fan for air movement.


    I built stadium-style risers to go under the light, to help even out the intensity across the whole light footprint. It doesn't fully mitigate the lower light intensities at the edges/corners, but it helps.

    This growing area was built primarily for 5.5" pots. I plan to use it mostly to grow on rooted cuttings before planting them outdoors, and that size pot has been (and should continue to be) sufficient. If I need to grow something larger I can remove the risers.

    The clearance under the light will allow me to grow plants up to about 2 feet tall, taking pot size into account, which is more than enough for most of what I grow (and will be enough for basil).


    I use a 4-bulb 2-foot high output t5 for my propagation. Two remaining cuttings are still in the dome - an Andromeda and a lacecap hydrangea - and both of them have already shown some root growth. It is the first Andromeda I've managed to root, which I'm excited about. The rest of my rooted cuttings from this season are already growing outdoors. I had 50 cuttings root, of multiple types of flowering shrubs including hydrangeas (all types), weigela, forsythia, own-root roses, barberry, azalea, and multiple things that I actually can't identify. I'll keep growing them and try to figure it out when they get bigger.

    The rest of the cells in the dome are basil seeds. They should germinate in about a week.

    I'll be growing in a bark-based medium for the excellent aeration it provides the root zone, and fertilizing with Foliage-Pro 9-3-6, a water-soluble fertilizer, in low doses with every watering (the structure of the growing medium I am using calls for frequent watering, owing to its excellent drainage).

    There is room for 35 pots; I will see how many of those can remain to the end of the grow without overcrowding becoming an issue.
    Last edited: Sep 27, 2016

    iHearAll Well-Known Member

    i always end up with tons of basil that i dont know what to do with..... so i switched to growing primarily tulsi basil since i can dry it and use it as tea. this is an interesting grow. very nice looking btw

    b4ds33d Well-Known Member

    ive always had great results with cuttings/widemouth mason jar/kratky and a nice window sill. i sell a shit ton of them to soccer moms.
    Budddha likes this.

    illsstep Member


    First seeds germinated last night, almost exactly 3 days after planting. Sooner than I expected. So far 40 of 66 are accounted for. I plan to keep the 35 most vigorous of the 66 and discard the rest. Keeping them covered for now; the top of this growing medium can dry out quickly, and I want to make sure they have deep enough roots to weather that.
    calliandra, roseypeach and wascaptain like this.

    illsstep Member


    7 days after planting. Out of 66 planted 46 have germinated (and 3 more germinated but may not make it). I'm a bit disappointed by the success rate - I think the coarse texture of my growing medium may have been to blame (poor contact with such small seeds).

    I removed the humidity dome, which will also increase the light intensity. I'm hoping I will not have to lower the light fixture, since it's not currently set up for that. But once the seedlings have a couple sets of true leaves I will move them under the LEC fixture anyway.
    Last edited: Oct 2, 2016
    calliandra, iHearAll and roseypeach like this.
    cat of curiosity

    cat of curiosity Well-Known Member

    roseypeach likes this.

    roseypeach Well-Known Member

    Nice set up! I love basil, I have three bushes outside right now that I'll be using for cuttings in for the winter to propagate more for my small garden shop next spring. I'd love to hear your method for rooting hydrangeas as I have a couple of different varieties I'd like to spread around my yard.

    Here's one of them

    Bubblin and calliandra like this.

    illsstep Member

    Very nice! I can only hope mine turn out so well.

    I am currently pretty low-tech as far as propagation is concerned. I use a 7" tall clear plastic humidity dome on a standard 11"x21" seed flat. I use small cells (the ones that fit 72 per flat) filled with a growing medium I like (I use the same bark-based medium for propagation that I am using for this grow. It consists of 5 parts pine bark, of a specific size; 1 part peat; and 1 part perlite. Plus lime to balance out the pH. This mixture provides both moisture and air to the root zone, and does not really get waterlogged - which helps prevent cuttings from rotting instead of rooting).

    For hydrangeas, my experience this year was that the time I took the cuttings was important. I tried several fairly early in the growing season that were taken from growth that was too new and soft to survive in the propagating environment I am working with. They wilted and died. The advice I ended up following with good success was to use growth that is new, but not too new; test it by bending the stem, and if it snaps almost immediately, it is a good age to use for cuttings. If it bends easily but does not quickly snap, it is too new and will probably wilt before you can get it to root.

    I took nodal cuttings: sever the stem immediately below one pair of leaves, and immediately above the next. This gives you a stem with a set of leaves at the bottom and a set at the top. Remove the bottom leaves and cut the top leaves in half (this reduces the amount of moisture the cutting will be losing - big leaves from hydrangeas can mean big moisture losses). I then dip the bottom inch or so of the cutting in rooting hormone, use a pencil to make a hole in the pre-moistened growing medium, plant the cutting and firm it in.

    And that's about it. Hydrangeas are pretty easy to root, and are supposed to work just as well with internodal cuttings (or even by splitting the cutting lengthwise to create two, each with one leaf! I haven't tried that method yet). I had roots appearing even on the parts of the stems that were not buried in the growing medium.

    My biggest difficulties were with temperatures under the dome. I raised the light (2 foot, 4 bulb high output t5 fixture) until it was about 6" above the top of the dome to help reduce the temperature inside. This gave me an average air temperature inside the dome of about 85°. Higher than I wanted, but usable. I could not find a good way to reduce the air temperature in the dome to the 70° range with the light on. If anyone has suggestions about that, I would love to hear them. Maybe the light fixture itself is more than I need?

    My goal down the road is to switch to an intermittent mist system for propagation (but to still root in soil). A project for another day..


    The seedlings looked like they were stretching, so I went ahead and rehung the light to allow for height adjustments. It is now about 4" above their leaves.
    Last edited: Oct 5, 2016

    roseypeach Well-Known Member

    Looking good! Thanks so much for the tip on the hydrangeas, I'll be trying that technique out tomorrow for sure. I believe the ones I took were too new (as you mentioned).

    Looks like you're going to have a ton of basil! The only advice I can offer is to make sure to pinch them back after a few nodes to get them to bush up. You've got a nice setup going, I bet you end up having much more than you expect! ;)

    calliandra likes this.

    illsstep Member


    First set of true leaves are coming in. I have started fertilizing at 1/4 strength with each watering. They are currently 4" below the t5, which is running 18/6, and I added a low-powered oscillating fan for air circulation.
    Last edited: Oct 14, 2016
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    illsstep Member


    Seedlings are starting to develop their second set of true leaves. Soon I'll be repotting these and putting them under the LEC.

    Growth had been slow. I found out that the bark mixture I am growing in can lock up N, and that fertilizing with increased N can be necessary. I upped the fertilizer to full strength and saw rapid improvement; now I will need to keep watching to decide if I also want to add an additional N source.
    calliandra likes this.

    illsstep Member


    I repotted 35 of the basil seedlings and put them under the LEC. The light is currently 30" above the seedlings. As closely as I can measure (which may not be super closely), the PPFD at that height is between 550 and 600. (I use a phone app to measure lux, and I found values on the web to convert lux to foot-candles, and then foot-candles to PPFD. That last one was the trickiest; I was lucky to find the conversion value for exactly my light, the 4200k ceramic metal halide, on Apogee's website.) The timer is set right now for 14/10, which should give a DLI of 28-29.

    I had a hard time finding a recommended daily light integral value for basil on the web. I did find some research indicating that essential oil amounts in the leaves increased as the DLI increased, up to a DLI of 25 (that was the highest value they used in the study). So I'm going to stay between a DLI of 25 and 30 and see how things go.

    I'm keeping the remaining seedlings under the t5 for a few more days, just in case I lose some of the repotted ones for some reason.
    calliandra likes this.

    calliandra Well-Known Member

    Ah it's so cool to see someone using DLI to figure out the amount of light their plants actually need! :D
    And your amphitheatre looks amazing! Really looking forward to seeing them grow in there!
    Cheers! :mrgreen:

    illsstep Member


    Tri-leaf basil plant. I think I may clone this guy when he gets bigger.

    illsstep Member


    And they are growing! I have still had trouble with N immobility due to the bark in the mix I am using (the supplier I use ordered a different product this time, and it seems to contain more sapwood than usual - very bad!). I upped the fertilizer to compensate, and the plants are greening up and growing steadily again.

    Right now, thanks to a period of very fair weather, I haven't had to run the heat or AC in my apartment for a couple weeks. The humidity is therefore pleasantly high. Right now during lights on I am running 80° with 60-65% relative humidity - and during lights out, 72-75° with 70-75% relative humidity. I'm quite happy with both.

    Most plants have three sets of leaves now, and some are working on their fourth. It will be time to cut them all back soon.
    calliandra likes this.

    Poontanger Well-Known Member

    Hey , luv ya work, but what are u gunna do with all that basil??..........i grow it each summer under tommies as a companion plant, & use very little, maybe a bit in homemade sauce.............& your correct , you wont find a better place to learn about growing under lights , than here.........there is many & varied theroy's, good luck with it


    illsstep Member

    I have absolutely no idea what I am going to do with this much basil. I also don't think I really understand how much I am going to end up with. Pesto, maybe?


    The plants are 5" to 6" tall right now. And it's about time for me to cut them back to promote branching. However, since space is my main restriction, widely-spreading plants are going to result in overcrowding.

    Unfortunately, I don't know much about the growth habit of basil and can't find much online to answer my questions. I want a little bit of branching to fill in the space I have, but I don't know if the plants will do that on their own or if they will have to be cut back. Most of them are starting to branch on their own:


    If that continues, they will fill in the space I have, no problem.

    Any basil growers out there that can chime in about how much basil will branch out if it is not cut back?
    calliandra likes this.

    Bubblin Well-Known Member

    It gets fairly bushy but my issue with it indoors was height. I had to prune emm often to keep them out of the lights.

    Poontanger Well-Known Member

    I know growing them outside, its best to top them, the new shoots , are a lot fresher, & the wind wont break em, but they always stretch , because there under my tommies, as Bubblin has pointed out there gunna head for the light, experiment , knock the top out of a few & see what happens
    Bubblin likes this.

    PlantLover300 Member

    Looks great. Basil will branch the more you cut it. And will produce two shoots where you prune. Feel free to butcher the plants whenever and your yields will increase substantially! Make sure if you see any flowers forming on the plants to snip them off. The flowers change the taste of the plant.
    calliandra likes this.

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