[boosh]

The pak-choi i sowed a few weeks back had 3 Varietys in the packet, going from light green to dark green leaves, the light green leaf variety has bolted but the other darker varietys have been ok.  first time iv'e grown this, tastes great. 

[viettaclark]

If you plant some in August it will go through the Winter!! (At least mine did last year.....)

[Irene]

boosh:

I planted a short row of the light green (yellow) this year, along with my regular dark green variety.

It grew well, and produced quite a bit before bolting but I ended up pulling it all as I truly preferred the dark green.

If you're willing to pick them smaller and keep sowing as you use I feel it is a garden must. We simply love this vegetable. Just planted another short row today.

You may wish to try Kailaan also. Another easy and fast growing oriental that I'm really having fun with.

[oldcow]

Pak Choy doesn't do well in the heat, but as suggested just plant it more densely and harvest it while it's stil small and you'll be fine. Or wait until the weather is a bit cooler...
As Irene suggests, it might be worth trying other oriental veggies for which bolting is a good thing since the flower stem is tender and tasty, such as kailaan or my current favourite, tsoi sim.

[gillie]

I have been growing the 'slow to bolt' variety Yuushou F1 and much to my surprise it has not bolted yet!

Gillie

[mobilekat]

My Red F1 (from Tuckers seeds) have all behaved, but sadly do lose the red colour when cooked (but taste blooming nice!)

Am developing a Pak choi addiction!- and well worth it as quite pricey in the shops!

[boosh]

Thank's for your replies, have noted down the varietys you have all sugested.