Tomato seeds

I have some Tumbling Tom tomato seeds. I made a small wooden electrically heated growhouse currently achieving 17 to 21c. I had planned to sow some tomato seeds in a growbag in the growhouse, but having searched the internet for advice, cannot find any reference to sowing seeds directly into a growbag, only for planting small tomato plants. I am obviously new to this so any advice would be welcome.

 

I think you'd be better sowing your seed in a good seed compost first and when they are ready transfer to the growbag, i think there will be to many nutrients in the growbag for seeds.

 

How to grow tomatoes in a growing bag

Welcome to the forum @Peter Sullivan ,

I personally can't help but found this.....any good?

 

...just realised you meant seed sowing...sorry.

 

Not a good idea to sow directly into a grow bag as @mazambo says.
The norm is to sow into a seed tray of a 4 inch pot and then transplant seedlings into single pots of around 4 inches.
Plant in the grow bag when about 8 to 12 inches high and the first flower buds are showing.

17 to 21C is that a day or night temperature, you will need around a night min of 16C for seedlings to grow well.

 

Thank you @mazambo. I have seed trays, pots and seed compost, so will start them that way.

Thank you @Upsydaisy. When the plants start growing I will follow the information you pointed me to.

 

Thank you @pete for that information.

I have a wifi sensor in the growhouse that relays temp/humidity to a display in the house. Just checked the max/min over the last 24 hours and it gave 21.3c and 15.8c. The heating is provided by a 180 watt 3 foot long tube heater with a thermostat so I can vary the temperature as needed.

 

Hi,
Just to help you understand why seed compost first,
The seeds have to breakout of the shell/pods etc and then push through the compost/soil to get to the light /heat etc of the "now" growing stage,
Seed compost is very ligh and wont hold very much moisture and has very little if any food value and so the differnce between the growing compost as in the compost growing bags is these bags are full of both feed and moisture keeping compound,

If you sow seed in such conditions as a moisture containing bag/pot's your giving the seed to much moisture and the seeds can rot,

Warning,
seeds have their own short term food in the pod/shell pre breaking out of these shell's/pods
But seed compost has no feed in them and so the likes of tom's need to be re,potted so the young "now plant" can feed and continue to grow,

Tip ref tom's
when repotting plant the new plant when the first leaf (common leaf) opens out fully into a good compost deep enough so these common leaf are just a little bit above the new compost,
By planting this way the new plant will grow much stronger and root much better as its now using all the plant stem to grow stronger rooting system,

 

You may well get away with broadcasting your seeds in a growbag, many times in the garden we are pulling up small tomato plants that have self seeded from our garden compost.

As @moonraker sways, the catch is, sowning this time of year is that a grow bag will hold a lot more water and with the seedling using so little its too easy for them to rot or get too cold.

Many of us know that when sown in a small pot, 50 to 100mm with a topping of compost or perlite, the strongest seedlings are often the ones by the outside of the pot where drainage is best and the heat warmest.

We also use a 3ft tubular heater but find the best results given if you have a small fan in there to distrubute the heat better and also seems to help the plants in other ways.
We use one of the USB 5v desktop fan with a 6" blade

 

Thanks very much to @moonraker and @ricky101. Very useful info

This forum is great, just like having an expert gardener advising me and putting me on the right track . Tomato seeds are now in pots of seed compost. I'm sure I will have more questions soon. Thanks everyone.

 

@ricky101
I have a usb powered fan kicking around somewhere, so will search that out and fit it in my growhouse. I'm currently much better at doing a bit of wiring or building a wood/glass growhouse than actually gardening, but hopefully that will start to change .
Thanks for the suggestion

 

Hi,

Do not know how big your growhouse is, but our enclosure, inside the greenhouse and used for growing orchids, is about 4 x 3 x 2 ft and one of these fans covers that area just right, strong enough to move the heat all around but no so the plants are over buffeted.

To say its quite moist in there did not expect the fan to last that long, but its been going 24/7 for 3 years now, still on ebay for £9.99
Used USB 5V as most mains fans not very will insulated against moisture, simple enough if using a little wall pack power supply.

We also have a heated bench area and a little heated seed tray which allow us to keep thing ticking over all winter.
Using a high temp seed tray, eg up to 20c, means you can keep the other areas at a much lower temp, yet the plants still growing ok.
Each area with its own temp control keeps the running cost down.

Also find some cheap led lights in these winter/early spring months helps the seedings and cuttings grow much better.

 

Hi @ricky101 identical fans in Home Bargains for £2.99. I've put 2 in the heated section of my greenhouse on a timer. Main problem was finding a plug to connect to 2 USB - so used an old hub.

 

Hi @CarolineL - did look at HB site, but think yours are 4" fans, not the larger 6" we use ..?

Not sure why you need to use a timer, partic if its heated, surely better to keep them on all the time ? plus they say a breeze /movement builds stronger plants.

If the fans are just that bit too strong you can readily drop the voltage by using a diode or two or one of the little adjustable regulator modules.

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Not diverging from Peters topic too much, just wondered if you had done any more to your moisture recorder /waterer ?
Have not myself as have been porting my aquarium code over to an Aduino compatible ESP32 module which has wifi and BT built in for around £10.
Think it will allow me to update the old Arduino Greenhouse controller as the latest screens like below have touch control so we can really fine tune the set Temperatures and send the data back to the house without cables as we currrently use.

Protoype board

 

Hi @ricky101 - you're right, they are smaller. They're on a timer because I'm a cheapskate! No, I'm afraid I haven't done anything further with the kit. As I may have mentioned, I was going to build it for a colleague at the botanic garden to use on proteas. However we have been concentrating on trying to set up the facilities for orchid seed sowing in petri dishes, so that has been the focus instead. Also I have lost my coding mojo for the moment. I spent so much of my working life with code that I have gone off it for now. Hopefully that will change fairly soon...