🌱✗ Tested and false“A scatter of Epsom salts will green plants up and stop blossom end rot”
Epsom salts are magnesium sulfate, and they contain no calcium whatsoever, so they cannot address a calcium problem. Worse, magnesium and calcium compete for uptake, so adding magnesium can make blossom end rot more likely rather than less. Most garden soils hold plenty of magnesium already, and adding more unbalances what is there.
Our read Blossom end rot is not a soil shortage in the first place. It is about calcium reaching the fruit, which is governed by steady watering, so the fix is a watering can and a mulch rather than anything you buy.
What to do: Water consistently and mulch to hold that moisture steady. Use Epsom salts only if a soil test has actually shown a magnesium deficiency, which is uncommon.
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“Strip the lower leaves off your tomatoes to ripen the fruit”
It works against ripening rather than for it. A tomato plant balances its own nutrition and physiology, and de-leafing upsets that balance, making fruit more prone to ripening problems. The advice is to keep it to a minimum and go no higher than the lowest truss.
Our read The leaves are what ripen the fruit. Taking them off to expose trusses to sunlight misunderstands the job: sugar arrives from photosynthesis, not from light falling on the tomato itself.
What to do: Take off the lowest leaves only, and only where you have a reason: yellowing, disease, or leaves lying on the compost. Stop at the lowest truss and leave the rest alone.
In Scotland: There is one genuine reason to thin lower leaves here, and it is not ripening. Almost all Scottish tomatoes grow under cover, where still, humid air drives botrytis and blight, so a little clearance at the base earns its place for airflow.
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- RHSDe-leafing can upset the plant's balance and make fruit more prone to ripening problems; keep to a minimum, no higher than the lowest truss
“You have to pinch out the side shoots on tomatoes”
Only on half of them. Cordon tomatoes are grown as a single stem and do need side-shooting, or they sprawl into a mass of leafy stems that carry little fruit. Bush tomatoes are the opposite: their side-shoots should be left to grow, because that is where the crop comes from. Pinching out a bush variety removes the plant you were trying to grow.
What to do: Find out which type you have before you touch it, because the label often does not say plainly. If it keeps climbing and needs support it is a cordon, so side-shoot it. If it stays low and spreads, leave it entirely alone.
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- RHSCordon side-shoots should be removed; bush tomato side-shoots should be left to grow
“Growing basil next to tomatoes makes the tomatoes taste better”
Doctoral research ran double-blind taste tests across three years, comparing tomatoes grown beside companions against tomatoes grown alone, and tasters showed no consistent preference either way. The twist is that the same work found tomatoes and basil grown together yielded around a fifth more than either grown alone, once planted densely enough.
Our read The pairing is worth making, just not for the reason everyone gives. It earns its place by using the bed well, not by changing how anything tastes.
What to do: Grow basil with your tomatoes if you want more out of the space. Do not expect the fruit to taste different, and do not pay extra for basil on that basis.
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“French marigolds among your tomatoes will stop whitefly”
Controlled glasshouse trials found French marigolds slow whitefly build-up on tomatoes, and identified limonene as the compound responsible. The condition almost nobody mentions is timing: planted alongside the tomatoes from the start of the season they work, but introduced after whitefly has taken hold the effect was minimal.
What to do: Plant them at the same time as the tomatoes, or not at all. Reaching for marigolds once you can already see whitefly is the one situation the research says will not help.
In Scotland: More relevant here than in most of Britain, since nearly all Scottish tomatoes are grown under cover, which is exactly where the trials were run.
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“Burying a tomato's stem deep when planting makes it grow extra roots and strengthens the plant”
This is standard advice, not folklore. Tomato stems root along their buried length, so planting deep, with only the top set of leaves above soil, gives the plant a larger root system before it starts fruiting.
What to do: When planting out, especially a leggy seedling, bury the stem so only the first true leaves sit just above the compost surface.
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- RHS — How to grow TomatoesPlant tomatoes deeply, so the first set of leaves is just above the soil surface – the buried section of stem will then produce additional roots.
