I plant perennials and shrubs until mid October or so, maybe even a little later than that. Just make sure to keep everything well watered, and they will be fine. Just remember, that success mostly comes from a healthy plant, and some of the clearance items aren't all that healthy to begin with.

It depends on the variety, but yes, research has shown that once temperatures go above 95 degrees, sweet corn pollen has issues. This is one reason people sometimes have ears that don't fill out well if they pollinate in high heat. I have found this to be true in my garden. Some varieties seem to pollinate very poorly in heat and some don't seem as bothered by it. Keep in mind that it is usually the high heat in combination with drought and/or low relative humidity that most affects the viability of pollen. As long as nights remain relatively cool, your corn might pollinate in the cool morning air, especially if the soil is nice and moist and the RH is higher. Many scientists believe corn pollen is "killed" in temps over 95 degrees, but I am not sure if it is truly killed or just impeded. I have had some heirloom corns pollinate in 100 degree heat, but then the nights were only in the 80s, so that may have helped. Usually, here in Love County we are hot and dry with relatively low humidity in July and August and that does seem to affect the corn pollen. You might have more summer rain (?) and higher relative humidity there, and that would work in your favor. When I grow Silver Queen,I usually plant in late March and harvest in June so it generally is pollinating before too much heat arrives. Thus, I don't know how affected it is by the heat.

I can't remember the name off hand, but there is a major nursery in Grand Junction, off I70 west of Horizon Drive. Although further south, I'm higher in altitude, so I'm in a similar environment winter-wise. I've successfully planted perennials through October. In late September, the nurseries around here have clear-the-space sales, and stuff is 60% (or more) off, so I often get lots of plants then. I have had well over 80% survival with these. The big problem is winter dryness, so a good mulch is very helpful. And check every now and again to see if the soil is moist under it all. It will take a few years for everything to get well established. Keep adding organic matter, and look into making a big compost heap off in a corner with newspaper, garbage, junk mail (tear out the plastic windows) catalogues, and all. It may take a few years to break down in this dry climate, but it all adds to the soil, sometime.

Ideal soil temp for germination is 45-55 degrees. As the soil gets warmer the germination rate tends to fall off. Summer crops of them for me are pithy and bitter but you likely don't get the heat I have. So I plant early spring under floating row cover to eliminate the flea beetle issue and then again in ate Fall. Dave