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Few newbie questios (mainly tomatoes)

Hey folks so my first time trying to grow stuff outdoors (had some little strawberry pots on my windowsil in the past which did okay), just got a little 6ft by 4ft plastic covered "greenhouse" in the garden.

Not loads of space so I'm just trying two varieties of tomato, two types of sweet pepper, a strawberry plant and a cucamelon (cos why not?). So they're in little seed trays right now (bit late haha but I don't mind)..

My main queries are...

1) When they get bigger than being in 3" pots, are those grow bags sold for tomatoes any good or is it best just to get very big pots (well..probably a plastic bin with holes drilled in the bottom) and fill those up, I imagine that gives better depth for the roots?

2) When it comes to feeding, a lot of basic/novice guides just seem to recommend tomato feed for....a whole lot of things. Now I'd imagine that's probably not best practice for everything? Should strawberries and peppers etc be getting this too, or should I buy specialist foods for them?

3) Is just buying a good brand of compost okay for growing tomatoes/strawbs/peppers? I notice some people have quite complex mixes (well not complicated, just 4-5 different products mixed together). Is it necessary or will they do reasonably well just in compost and given appropriate food at the right time?

4) Is growing marigolds the best way to handle green/blackflies? My past attempt at an indoor cherry tomato plant failed despite getting some tomatoes off it as seemingly out of nowhere it was suddenly covered in aphids! It wasn't even the natural season for them was horrific. So if you are meant to grow marigolds, must they share the tomato plants pot/grow bag or just be nearby? If they share the pot, is it as simple as just planting some seeds in there once they graduate from the 3" pots or would they not flower  in time for protection and need growing now in their own pots and transferred later?


cheers for any help guys!




  • pansyfacepansyface PEAK DISTRICT DerbyshirePosts: 18,686

    1. Pots are good. In some ways better than growbags because they are easier to move around and fit into odd gaps.

    2. Tomato feed helps plants that flower and fruit to do their best. Some feeds are better for making leaves rather than flowers and fruit.

    3. Buy the best compost that you can afford.

    4. No idea about marigolds versus aphids.

    Don't think about putting your toms, peppers etc out into your greenhouse until all the frosts are over. It won't protect them unless you heat it.


    Apophthegm -  a big word for a small thought.
  • Ah yes I am aware of that pansy should have said, they've literally just emerged from the soil recently so it''ll be a while before they've outgrown 3" pots anyway, but I'll check out the weather in May. I don't think trying to heat this thing would really work tbh, it's just a pretty cheap plastic thing so doubt it has that much heat holding ability when its cold compared to a proper glass job.

    Cool so tomato food for all, are their "better" feeds when it comes to tomato food? I mean you have supermarket own brand then stuff costing treble or more of their price, yet most seem to discuss having the same basic chemicals NPK and the same ratio, but I doubt it's that simple or everyone would just buy Wilkos own brand lol.

  • Dave MorganDave Morgan Posts: 3,123

    Marigolds don't actually deter greenfly/blackfly in my opinion, but they do attract hoverflies which feed on them. Usual result is less if not no pests. I did try it for myself planting them together in the same pot, the results were fewer tomatoes, so now I put them near the tomatoes again fewer pests and more tomatoes.

    There was a recent test in GW mag about feeding and watering toms and watering every 3 days seemed to produce the most toms with feeding once a week. I don't think it makes much difference when coming to bags or pots although as pansy says pots are easier to move and tomatoes aren't deep rooted plants anyway they spread to the space available in bags, and depth of pot ,I find, doesn't seem to make a difference just the width at least 8 inches. As for feed I buy Wilko own brand, they are all made by the same people it's the cost that's the difference and personal preference.

    Best of luck and feel free to ask as many questions as you like, the only stupid question is the one you don't ask.

  • Hi Joeimage have a look at Growing Tomatoes Simon Knott and Marigolds&Broad beans both threads showing at the moment. I was going to use Tomorite giant grow bags this year but after listening to forum friends have decided to use buckets with holes drilled in the bottom. The seedlings I have growing indoors are about 3"tall and should be at least 10_12" before being moved to the greenhouse possibly early May?? (Toms cues peppers and chillies) nothing as exotic as cucamelonimage

    I'm sure you aren't late with toms I applied for the seeds being sent out via BBC Gardeners World program trialling blight resistance varieties image



  • GemmaJFGemmaJF Posts: 2,286

    My first year with tomatoes, glad you asked your questions Joe as I was wondering about these things too.image

  • CeresCeres Posts: 2,105
    Tomato plants do very well in large pots and you can plant a marigold or two with each tomato plant......I make sure the marigolds are a reasonable size before they go in the tomato pot so they have a fighting chance. I have no idea if they keep the aphids off but they make nice cut flowers for small vases and they make the greenhouse look jolly.

    I grow my tomatoes in New Horizon peat free multi compost, have done for years, and get a good crop. At the end of the season the compost goes on the garden and helps to improve the soil.

    Last year I adapted the ring culture method to large pots and the plants grew far better.
  • cheers guys and no probs Gemma haha, my first time with anything so honestly if I get any fruit at all let alone cucamelons I'll count it as a success!



  • WelshonionWelshonion Posts: 3,114
    Sometimes the dilution rate is different between the tomato feeds and the more expensive one can work out cheaper.

    Start feeding when the first truss or group of tomatoes have formed.The flavour of home-grown tomatoes is much better than anything you can buy.

    Good Luck.
  • BobTheGardenerBobTheGardener Leicestershire, UKPosts: 11,131

    Also peppers don't require the same strength feed as toms - use it at half strength.  The better liquid tomato feeds also contain trace elements - look for that on the label.  Having trace nutrients can help if the compost is lacking anything vital to healthy growth.  Under-watering is also better than over-watering and always water the compost directly to avoid wetting the leaves as this encourages fungal infections.

    A trowel in the hand is worth a thousand lost under a bush.
  • 1 25cm pots are fine, plastic not clay. Long tom pots are deeper. Growbags don't really have enough depth so most people who use growbags sink a bottomless pot on top of the growbag. I use cardboard carpet roll because there's a carpet fitter round the corner and I asked for permission to take from his permanent walk-in skip. I'll probably go with pots this year as I cleared the co-ops of their planters at the end of season (1/4 price or so) 

    2 I usually make my own* feeds if using pots but the own brand is usually as good as the proprietary (though compare the NPK, micronutrients and trace elements. * (wood ash, banana skin, magnesium sulphate, garden compost, crushed bones, urea, seaweed etc).

    Generally speaking, to support the green growth one gives the plants more Nitrogen (N), when fruiting something with more Potassium (K), though still use a broad fertiliser. If one is too selective such a narrow spectrum approach throws other nutrient uptake out of kilter eg too much K the plants won't take up Mg. If you use a decent growing medium you will only need to tweak nutrients at fruiting. It's worth reading up on plant nutrition.  

     3 Perhaps you could plant direct into the soil inside the greenhouse? The plants would get a good root run, you wouldn't have to be too particular about watering which frees you up if you need to go away for a few days. Composts vary widely even in the same product and certainly year-to-year. 

    4 I've never got round to co-planting toms and the Tagetes (marigolds) I've grown from seed. I've always usually short of pots by the time the marigolds are ready for potting on or the toms are ready for the final potting up.

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