I love this — you’ve built yourself a perpetual basil machine, on a balcony no less! Buying a grocery pot each spring, dividing it, then rooting the prunings on the counter while you cook with them is exactly the trick more people should know.
And you’re right about “infinite basil” — each cutting is a clone of the parent, so you can keep going indefinitely. Light is the deciding factor, just as you say: bright light (or a grow light in winter) keeps them lush rather than leggy. The only thing I’d watch long-term is disease — if a plant ever looks off, start fresh from a healthy cutting rather than passing it on. Brilliant routine, and a great example that you don’t need a garden to grow your own herbs. Thanks for sharing!

Great question, and the good news is basil loves being trimmed — it’s almost impossible to over-help it as long as you follow one simple rule.
Always cut just above a pair of leaves. Look down the stem and you’ll see points where two leaves grow out (the leaf nodes). Make your cut about half a centimetre above one of those pairs, using clean scissors or snips. The magic of this is that the plant responds by sending out two new stems from that point — so every cut you make actually gives you a bushier, fuller plant. Cut in the wrong place (halfway up a bare stem) and you’ll just be left with a sad-looking stub, so always aim just above a leaf pair.
Trim from the top down. Since your plants are around 30 cm (1 ft) tall, you’ve got plenty to work with. Decide how much height you want to take off, find a healthy pair of leaves at that level, and cut just above it.
Don’t take off more than about a third in one go. This is the one safety rule. Basil bounces back beautifully, but it still needs enough leaves left to feed itself and recover. So if your plant’s quite tall and leggy and you want to bring it right down, do it in stages — take a third now, let it put out fresh growth for a week or two, then trim again. If you only want a light tidy-up, just nip the tops.
Two bonuses while you’re at it: pinch off any flower buds you spot (that keeps the leaves tasty), and don’t waste the trimmings — pop the healthy ones in a glass of water and they’ll root into brand-new plants in a week or two. Regular trimming like this is genuinely the secret to a big, bushy, productive basil plant, so trim away with confidence.

Thanks for your reaction and question.
Here’s the thing most people don’t realise: the fungus behind basil Fusarium wilt is a soilborne one, and it’s incredibly long-lived. It doesn’t die off over a winter, or even over a year. It can survive in soil and old plant debris for the better part of a decade. So when you reused the pot and soil from last year’s plant that died with the same symptoms, you very likely carried the disease straight over to your new basil. It’s not a sign you did anything careless — you’ve clearly been looking after it well. This particular fungus is just much more stubborn and long-lasting than anyone expects, which is exactly why it catches people out.
So yes — the soil could absolutely have been the source. A couple of other things worth knowing: it can also arrive on infected seed, and it tends to affect sweet basil most, while some lemon and purple basils show more resistance.
What I’d do now:

Don’t reuse that soil for basil again. Bin it rather than composting it, so it doesn’t spread.
Clean the pot properly before reusing it — wash it in hot soapy water, then give it a soak in a dilute bleach solution, rinse well and let it dry. (Or just start basil in a fresh pot to be safe.)
Start fresh: new, clean potting mix and, ideally, fresh seed — or look for a Fusarium-resistant variety if you can find one.
Keep basil (and mint, which can quietly carry it) out of any soil you suspect is affected.

There’s sadly no spray that cures a plant once it’s infected, so prevention really is the whole game here — and a fresh start with clean soil and a clean pot is usually all it takes. Don’t be put off; your next basil has every chance of doing beautifully.

Great question — and the honest answer is “both can work, depending on what you’re after.”
You can actually root basil cuttings indoors at any time of year, so you don’t have to wait. But here’s the nuance:
Spring is the easiest, most reliable time. As the days lengthen and warm up, cuttings root faster and grow away strongly with the least fuss. If you just want the best success rate, spring into summer is the sweet spot.
Taking cuttings before winter is a smart move too — just for a different reason. Supermarket basil is short-lived, so rooting a few cuttings in autumn is a lovely way to keep your basil going through the colder months rather than losing the plant entirely. The one catch: basil needs plenty of light, and winter days are short and weak. So if you root cuttings heading into winter, give them your sunniest windowsill, or pop a grow light over them — otherwise they tend to go pale and leggy.
Since you’ve got an indoor supermarket pot, here’s what I’d do: take a few cuttings now (those supermarket pots are actually several plants crammed together, so they’re perfect for it). Snip healthy 10–15 cm (4–6 inch) stems just below a leaf node, strip the lower leaves, and pop them in a glass of water on a bright windowsill, out of harsh direct sun. Keep them somewhere comfortably warm — around 18–21°C (65–70°F) — change the water every few days, and you should see roots within one to two weeks. Once the roots are an inch or so long, pot them up.
That way you’ve always got fresh basil on the go, whatever the season.

Good question! The short answer is yes — bottom watering still works even with a layer of rocks or stones at the bottom. As long as the water can reach the soil, the potting mix will draw it up. Fine soil actually has a stronger “pull” than coarse rock, so it wicks water right up out of a wet rock layer.
The one thing to watch: water doesn’t climb up through rocks very well, so if you’ve got a deep stone layer and you only sit the pot in a shallow dish of water, the water can end up sitting in the rocks without reaching the soil. The fix is easy — just use a bit more water so the level comes up to where the soil starts, and give it a little longer to soak. Pop the pot in the water for 15–20 minutes, until the top of the soil feels just moist, then lift it out and let it drain.
If you’re wondering whether you need the rocks at all — honestly, you don’t. The things that really matter for healthy roots are drainage holes in the pot and a good, free-draining potting mix. A lot of us were taught to add a rock layer “for drainage,” and there’s actually a lively debate among gardeners about whether it helps, does nothing, or makes things a touch wetter. For bottom watering specifically, the simplest, most reliable setup is just potting mix all the way down with good drainage holes. But if you’ve already potted up with rocks in the bottom, don’t worry — just water a little deeper and your herbs will be perfectly happy.

Thanks so much, glad it’s been helpful! And yes — go ahead and pinch those flower buds off. Basil tries to flower (bolt) whenever it senses the season pushing it to set seed, and once it does, it puts its energy into making flowers and seeds instead of leaves and roots. For a cutting that’s still rooting, you really want all that energy going into the roots, so removing the buds is the right move.
Just pinch them out with your fingers (or snip with clean scissors) right above a pair of leaves. That keeps the plant focused on growing, and as a bonus it encourages bushier, leafier growth lower down. Don’t worry — your cutting will keep rooting happily even though it had a go at flowering.
One thing to expect: basil is persistent, so it’ll likely try to flower again, especially in warm weather. Just keep pinching the buds off whenever you spot them and you’ll keep the plant leafy and productive. Sounds like your cuttings are coming along well — nice work.