Tomatoes under 400W MH - advice?

12 years ago

First winter of trying to grow tomatoes under lights. Started seedlings under T8's a couple months ago and they are now 1 foot tall. I have moved them inside as we'll be in the 30's at nights now.

I have them under a large 400W MH lamp. I also have a 400 HPS lamp that I will switch over too when the plants are closer to flowering.

I expected the light to be hotter - it doesn't seem to bad...but I do have a fan that runs about 15-30 minutes every hour.

I am growing these plants in ProMix vegetable mix only.

Does anyone have any words of wisdom or advice on how best to grow these plants to maturity and provide some nice tomatoes? Im doing a 12/12 cycle... I know most will suggest 14/10 at least - but its my utility bill. ;-)

Sort by:Oldest

Comments (10)

TheMasterGardener1
12 years ago
Check your type of tomatoes photo period. adjust timer accordingly. Are they determinate tomato variety? They would be better indoor type to grow. You need to keep your room 80F or lower, not only is that 75-80F peek growing temp, but pest will thrive in temp above 85F. So if it takes running fans 24/7 then do that. The room needs fresh are if it is a small area. Humidity needs to stay in the 50% area aswell, exausting air out of the romm lowers humidity. Additional fertilizer may be needed, smaller the container the more fertilizer/water the plant will need frequently. One 400w hps will support one large cherry tomato plant.
0
clones2
Original Author
12 years ago
Thx for the insight...Ill definitely keep the room under 80. Its a 12 x 12 room with 2 windows... I do have a humidifier I will use if it gets to try... Im trying 2 bush tomatoes and 2 smaller indeterminates...

Indeterminates are mostly for a test to see what will work...

Thanks again
0
Related Discussions
Tomato disease?
Q
Comments (3)
I probably would not. I might cut off the affected leaves. Probably misting the plants allowed some parsitical bug or bacteria to live on them and they transmitted the virus. Like I said don't worry about it. your fruits should be fine.
...See More
Please help me get my tomato seeds off to a good start
Q
Comments (4)
Ballplayer, Sure looks like you keep trying. I'm not sure what the problem is but I can tell you how I do mine. I usually start 500-600 seeds a year, FWIW. First, I get one of those plastic to-go trays with a lid from a restaurant. Drill small holes in the bottom of it. I like Ferti-lome Ultimate Potting Mix though every once in a while, I find a small piece of bark or a twig that needs to be remove. I add about 1.5" of this, then use a tweezers to place each seed individually, just barely in the mix. Cover that with a thin layer of potting mix, maybe 1/4". Set the entire thing in a tub of either rain water or aerated (for 24 hours or more) tap water. Let it sit until the mix is sopping wet. Remove it, put the lid on the tray and either place it on a heat mat set to 85 degrees or during summer, just on a bench. I do not water it again, at least not for a week or more. Usually within 3-5 days, the first seeds germinate. As soon as they do, I put them under CFL bulbs, as close as I can after removing the lid. When the mix is almost dry, I set the container back in the tub but usually add a very small amount or Tomato-tone fertilizer. This is lower in nitrogen but high in other ferts plants need to develop good roots. Put it back under the lights, then repeat as necessary. Once the seedlings develop at least one good set of leaves but usually two, I prepare nursery trays. Fill with potting mix, set in that tub of water and compact the mix, then refill and compact again. Let it sit, usually for an hour or more - however long it takes to throughly soak the mix. Remove it from the tub, set it aside for the evening. By the next day, excess moisture has drained off. Using my finger, I poke a hole in the mix. I gently remove the seedling (it helps to have that mix damp, but not wet) and place it in the hole until just the leaves are showing, then tamp the mix around it. When I finish a tray (6-36 plants) I put it under lights, again as close as I can. Then, I let the plants grow, watering them only when the mix gets dry (usually the plants will start to wilt a bit). Once the plants get 8-10" tall, I transplant them into 5-7 gallon pots. That's for my dirt plants. Next is the hydro ones. HTH, Mike
...See More
First time indoor garden, reasonable MH setup
Q
Comments (7)
Hey slimak, thanks for the quick reply. THe $300 was in reference to prices that I've seen for other systems or even just components of systems. I checked my electric bill earlier and calculated that I should be running an expense of around $20/mo between fan and lighting (based on cost/KWh of ~$0.095 and 18-20h/day). And, I agree with you about them being expensive tomatoes. I'm justifying it with the following: A) my parents are growing a few sun sugar plants now and...I'm embarrassed to say, but I might pay $9/lb for the damn things, they're that good. If I can have them downstairs for the picking during the winter I'll be a very happy man. B) I'm looking at this as a trial run for indoor planting and if it goes well I will likely add more, and use it to start seedlings indoor next year. The last two years that I've tried them I've had relatively weak seedlings, so it serves a dual purpose. C) Per above, the electricity costs should be somewhat lower, lowering the expense to be slightly more reasonable D) I just think its a really cool idea and I have a really bad habit of picking up expensive hobbies. Trust me, it can't be nearly as bad as fly fishing in that regard. So, for now I'm mainly hoping that the system I was looking at is serviceable. I figure If I'm going to start an expensive hobby and it really really doesn't work out, I can stop spending the extra $20 (or $30) on electricity and I'm just out the upfront cost of $120+-, versus getting a more expensive system. At the same time though, there's no point in getting something that's too cheap to be effective. Just trying to meet the right balance there. Finally (and apologies for the length), I had read about bending (training) the tomato plants to vine up a circular trellis, with the implication being that it should lead to more efficient use of the light and likely provide enough room within the light's effective area for an extra plant or two. Any thoughts on that?
...See More
600-watt hps/mh or two 400-watt hps/mh
Q
Comments (2)
Shrubs n bulbs Are the bulbs in your name light bulbs or flower/vegetable bulbs? : ) Thanks for your response. I am still having a difficult time deciding because this particular dealer offers the 600watt unit with an electronic ballast but the cheaper 400watt is magnetic. Further, the 600 watt systems, whether magnetic or electronic, seem to have a higher light per watts ratio, but there doesn't seem to be as many bulbs available. In particular, I am wondering about the availability of "full spectrum" light bulbs, such as the Philips MasterColor that Mr. Meyer has suggested, in a 600 watt version. In that regard, I am wondering if I might do as well or better buying an MH system instead of a HPS system. But I am also unsure as to whether "full spectrum" light bulbs are available for MH fixtures or how the costs compare with "full spectrum" MHconversion lamps like the Philips. Finally, I wonder if for fruiting of tomatoes and peppers I might do much better with regular HPS than any conversion lamp due to the lower light output of the conversion lamps. Any thoughts on that anyone? wi-northernlight Bob
...See More
TheMasterGardener1
12 years ago
Im glad it helped. Keeping the humidity below 50% is better than above so you might need a small de-humidifier, but taking air out of the one window and allowing a vent to let air come in another would be ideal. Be ready to trellis the indeterminates aswell.

Good luck.
0
hardclay7a
12 years ago
Clones2;
Tomatoes are perenials most often grown as annuals. In their Geographical location of origin (equatorial South America), days and nights are of near equal length all year round. They are not photoperiodic, although you will experience faster growth and production with longer day cycles. So feel free to experiment with shorter day cycles to save on your utility bill. My tomatoe seedlings grow fastest at around 18/6, this seems to be the upper limit. I would suspect the lower limit to be around 8-10 hours of light per 16-14 hours of dark providing they are getting lots of lumens, spectrum, and adequate CO2 during those 8-10 hours. Let us know how you make out.
Good Luck,
Ken
0
clones2
Original Author
12 years ago
They seem to be doing decent so far. They are 12" - 20" tall...

Will it really help if I switch over to my 400W HPS lamp when the plants get a little taller to help with fruiting?

Will I still get good fruit from a MH or is it a better idea to switch to the HPS?

I got my first flower on one of the determinates. A couple plants seem a little weak in the main stalk so I'm going to try and keep the fan on them longer. They are just starting to send out their first "suckers".

But I absolutely love having a little "farm room". :-)
0
project_gardener
12 years ago
I grew tomatoes last winter under a 400w MH and next to them I had a 400w hps. They grew the same and both set loads of fruit. Here's a video clip of it from last March when I was near the end of my indoor grow.

This winter I'm growing peppers and was thinking of cucumbers too.

Here is a link that might be useful: Indoor Tomato Video Link
0
clones2
Original Author
12 years ago
Watched your video... those Micro Toms are pretty cool.

I'm wondering what other miniature tomatoes would be open-pollinated or heirloom variety...?

I think I need to look into hydroponic systems as well. Everything Im doing right now is pro-mix potting soil. Its working ok - but Im thinking the hydroponics would work better?
0
t-bird
12 years ago
great video project gardener! You are several levels ahead of me so very informative! Duh! do determinants indoors! I've got about 8 indoor plants that are becoming monsters, and I have tiny tim seeds - why didn't I consider that???

Can you elaborate on your various light set ups? Bulbs, etc?

Thanks!
0
clones2
Original Author
12 years ago
I had an interesting experience this winter to say the least... thanks for bring this back to the top. :-)

My 400 watt Metal Halide lamp works awesome for the tomato plants. I started some plants in soil and the plants grew great. My issues were not getting enough buds to produce fruit, fairly small fruit, plants that got a little too big, and soil that dried out very quickly.

I quickly tried to start a DWC hydroponic system and was able to grow 1 plant about a foot tall. But it grew with a weak stem - nutrients were probably a bit off.

Next year - I will attempt a tomato in the DWC system and one in soil. Try to see what the difference is in growth rate, will probably add some perlite to my soil as well to get it hold some moisture longer.

All in all - I was very happy with my light system. My light is basically a heavy duty shop light that i bought with a new bulb for $40 off craigslist.

I purchased a 400 HPS Lamp as well - and never needed it as my tomatoes and peppers all bloomed extremely well.
0
project_gardener
12 years ago
@ t-bird,

I'm using two 400watt MH made from warehouse lights. I paid $30 each. I have a new crop going now and just started to get tomatoes. I switched the bulb out to a HPS bulb that runs on MH fixtures since they started flowering. I have 2 indeterminate heirlooms going right now. They aren't as crazy as last years crop. Very happy with them.

Here is a link that might be useful: some photos in my blog
0

Tomatoes under 400W MH - advice?

Comments (10)

TheMasterGardener1

clones2
Original Author

Related Discussions

TheMasterGardener1

hardclay7a

clones2
Original Author

project_gardener

clones2
Original Author

t-bird

clones2
Original Author

project_gardener

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

Tomatoes under 400W MH - advice?

Comments (10)

TheMasterGardener1

clones2Original Author

Related Discussions

TheMasterGardener1

hardclay7a

clones2Original Author

project_gardener

clones2Original Author

t-bird

clones2Original Author

project_gardener

COMPANY

BUSINESS SERVICES

GET HELP

CONNECT WITH US

clones2
Original Author

clones2
Original Author

clones2
Original Author

clones2
Original Author