This Forum will close on Wednesday 27 March, 2024. Please refer to the announcement on the Discussions page for further detail.
Greenhouse Tomatoes in pots
I have been growing tomatoes in my greenhouse for a number of years, mainly in growbags, I have grown bush cherry varieties outside in a pot and have found the root growth appears better than in the growbag. I have decided this year to grow my greenhouse toms in pots. I wonder if anyone has suggestions for the optimum size pot to use for this purpose and possibly the best form of compost.I have used the usual tomato feed but understand Calcium nitrate, epsom salts and fish bone meal are good additions to the growing medium during the season and I may get better results this way. Any thoughts?
0
Posts
As big as possible really, to reduce the amount of watering needed. 25cm diameter, 30cm tall pots are about the smallest I use. For the last 10 years all I have been using is comfrey 'tea' to feed them with excellent results. Feeding should only start once there are flowers on the first truss as feeding before then will result in too much leafy growth. For that reason, it is a mistake to mix fertiliser in with the potting medium before planting, so just use a good quality multi-purpose compost in the pots and commence feeding once they start flowering. A good tip is also to avoid getting the leaves wet when watering or feeding as doing this will reduce the chances of fungal leaf diseases taking hold, such as blight or the many types of leaf spot.
Fab advice. Thanks Bob.
Thanks Bob, I have been feeding as you suggest for the past few years and totally agree about avoiding wetting the leaves to cut down the likelyhood of fungal diseases. comfrey tea is something I have never heard of! I will do some research. I was thinking of 30cm wide pots would you agree that is optimum or would you suggest slightly larger while I am getting them? I believe the depth is as imprtant, am I right?
I would sugest 40cm pots at least, plus as deap as you can find. I have noticed that even when using larger pots the roots of the tomatoes will escape from any largish drainage hole down into the soil, this in a poly tunnel. To my mind growbags do not allow enough root growth unless you just grow one plant per bag, so you may as well use a container.
Thanks Mel, so size is important! I will take on board your suggestion.
I think on Gardeners' World a few years ago they grew the toms in Grobags but, up on end as it were, cut the top end off, planted the tomato plant. Mind you the trouble with that is trying to keep the Grobag perpendicular and stabbing a few holes in the bottom for drainage. Just a thought.
2014, I grew toms in greenhouse, 12 inch diameter pots, they grew really well, BUT in the March I got (well, the toms did!) blossom end rot, because it was so hot in the day, and normal March temp at night, it was cured with a dose of epsom salts, but I found trying to keep them cool and properly watered was a challenge, so after that I have always grown outside.
Thanks John I think I agree perpendicular grow bags go against nature!! I will stay with the pots.
I have ordered some 36cm diameter pots and look forward to a bountiful harvest.
Nanny I am so pleased it was the toms with the end rot!! I don't heat my greenhouse, so tomatoes in March do not happen for me, nor I hope any end rot!! Thanks for your input, I do grow some outside as well (I like tomatoes!!).
What is 40 cm ? I use ten inch pots to good effect,decanting growbag material into them and standing on a tray of small pebbles the roots go down into the pebbles it is where I water, the plants crop well this way.
You don't need to buy pots - a trip to your local tip - sorry, 'waste reception centre' - will generally produce a good selection.
To make comfrey tea, grow a few plants of Russian comfrey and just before it flowers cut it down to the ground. Chop up the leaves and put them in a large bucket or smallish bin and cover with water. Put a lid on and leave it for several weeks until it smells disgusting. Apply nose clip. Strain it into another bucket and bottle it. Dilute 1 + 10 and use it to feed fruit plants,especially tomatoes, with the potash they need, . Put the sludge on the compost heap and cover with something nicer-smelling like manure. I kid you not -it's revolting!
Plant it this spring and you may get a harvest in time for this year's tomatoes. Or not. In future years you'll probably get two crops.
You can do exactly the same with nettles to make a high-nitrogen feed for leafy crops like brassicas.