I have a lovely patch of dandelions
Pick the flowers (and maybe the leaves as well) and use them in a salad. Then they won't set seed and re-grow.
With our garden, bear in mind it is now late autumn in Sydney, but because we are a frost-free area, we can grow stuff in winter too.
Herbs - most are settling down for winter. Basil is just about finished although I've continued pinching some of it back so I'll have some for a while. Parsley - I can usually keep it going through winter. Thyme, oregano & mint are getting woody but still in leaf. Tarragon is currently flowering (or trying to) but I just cut it back hard, cutting off the flower heads, to make a litre of concentraqted (boiled down, reduced) tarragon vinegar. That will allow me to make bearnaise sauce through winter, even whwen the tarragon is dormant in the soil.
Vegetables - currently we are picking loads of lettuce (oak-leaf) which is so thick it is in danger of choking itself in the garden. Brussels sprouts - caterpillars got to one plant but I think it's still alive even though I thought the heart had been eaten out of it. The other plant is flourishing, but still small. I should plant beans now, haven't yet (easy child's wedding slowed me down). Instead, I have tomatoes self-seedede all tyrough the vegetable bed and I need to remove them, they won't do much over winter (I speak from experience). However, if I can warm the roots they might fruit for me. So I'm planning on planting them in upside-down plastic pots (made from clear juice bottles) and growing them against the (metal) fence.
Other vegetables - bok choi (just about finished, they're hidden somewhere beneath the tomatoes), some other Asian greens (I've forgotten what they're called, I just know how to cook it). Fresh chillies are still growing, more fruiting on my small potted chilli bush. Snow peas currently in flower plus a few pods already developing.
I've got some violas to plant out also, we do still get flowers in winter.
One herb I can recommend, if you can find it - salad burnet. It is supposed to stay green through winter, it's pretty (looks like a green fountain of round serrated leaves on long stems) and has a mild cucumber taste. Youcan eat the young leaves in a salad or cook the older larger leaves. I read that because it stays green and growing when just about everything else is asleep beneath the snow, it used to be used to ward off scurvy in winter, eaten as a vegetable or in a salad. Not tat we have snow where we are.
ON the windowsill I have a candy pink miniature cyclamen. To keep it happy, I put ice cubes on it occasionally. Our winter nights here rarely drop below 10 C (50 F). I know, I'm a wimp!
But it does mean I can keep gardening all year round, even if it slows down a lot over winter.
Marg