Gardening Australia

It might depend on where you live. For example, basil is frost sensitive, so where I live it won't survive outdoors in winter. Coriander races to seed in heat, so even staggered plantings won't help a whole lot in a hot summer. Parsley might do okay with a few planted at different times of year; at least it seems less driven by season than the other two, in my limited experience.

You could have more success with indoor pots, if that's an option for you (that said, I've recently had a parsley plant going to seed in my kitchen, so results will vary).

And if the plants start flowering you can prolong their usefulness by pinching off the flowering stems - though that only buys you some time, rather than preventing the process entirely.

I've had a lot of success with basil indoors in a sunny position. Even indoors the coriander is pretty fickle. I've not had a lot of success with either basil or coriander in the garden, but am persisting in trying to find the right spot. I am hoping to get a couple of self-seeding patches of coriander growing if I can find the right spots.

In theory you can use varying micro-climates in the garden to extend the growing season, so I am trying a shady spot next to the house that will hopefully keep corriander growing a bit later in summer (but may be too shady over winter) and will try another position that is sunny over winter and hopefully get it producing earlier in the season (but will send it to seed earlier over summer).

The parsley I mostly just let self seed - I have found that the flat leaf and curly leafed varieties seed at slightly different times, so I will usually have one of the two growing well. They also grow at different times in different spots, and there will often be seedlings popping up in new spots while other plants are more established - having crops at different stages is mostly a matter of selective weeding rather than specific planning with parsley!