It's way too hot to use 2,4-d. It should only be used when the highs are below 90. It's probably better to be on the safe side and not use it unless the temperatures are below 85. Your best bet at this time of the year is to hand pull, but that's not very feasible if it's 50% of the lawn. Somebody posted a couple of years ago about diluting Roundup to about 1/4 strength, putting it in jars and partially burying the jars with some of the bindweed stuck in the jar. I think he did it in the fall as temperatures were cooling down. The idea is to kill the bindweed slowly enough that it draws the roundup into the roots, killing the entire plant, rather than just the part that's above ground. Since many of the vines that you see above the ground actually belong to one plant, doing this in one spot can cause bindweed to die in many other spots as well.

Joe, I don't think the problem is how cold it gets in the winter. You'd have to protect it anyway. In my opinion the main problem is how fast the area you plant it in warms up in the spring, and how much heat it gets during the growing season. I tried Celeste (which is very early) in the ground here, and it didn't ripen (even though it ripens in pots). It just started too late because the ground was so cold. I think it can be done, but the conditions have to be very good.

There are still the himalayan berries here now, a little later than some years but I am not picking blackberries much past the end of our native small types....and those were a good three weeks later than usual. Long, cool Spring into early summer, delayed many things....raspberries, blueberries too. My neighbor with the rhubarb interspaced many sun flowers in among her things and some along our shared fence for me to enjoy...some are finally fully blooming this week.

If you have a spot for them, I'd by preference plant them directly into the ground. I've sometimes had problems with pots not draining well around the time of the spring thaw(s) and so I now plant directly into the ground, no matter how late it is (though earlier is better in the fall) and then mulch to keep the plants from heaving. I've never lost a plant this way.