Here in Arizona where it regularly gets to 115F, we need to be careful about excessive heat. Cucumbers don’t mind humidity, so no worries there. To fight the heat, plant in an area that is shaded for the hottest part of the day. A sheet of newspaper hung directly over the plant won’t work, the edge of the shade of a tree works very well. Second best would be 50% shade cloth, creating shade for at least 5 feet on the north side of the plant. Heat travels well, and shade needs to be substantial for the plant to benefit.
To get the most benefit out of the shade of a tree, plant so that the area gets sun for 3-4 hours in the morning, and about the same in the afternoon. My plants are in white 5 gallon buckets this year, allowing me to move them from full sun (spring and early summer) to part shade between noon and 4pm in mid-summer and early fall. The sun sets at about 7pm in June. I do not move them every day, just when the season demands it, or when I think a storm may drop hail!
To help, here is a poorly drawn diagram.
Trees do not provide full shade, so placing the plant near the center will mean direct sunlight when temperatures are cooler in the morning, and less-scorching in the afternoon/evening. Being near the edge of your tree’s canopy means keeping the plant out of that deep, dark shade.
Keeping your cucumber vine near the east side of an awning will mean direct sun in the morning when temperatures are cooler, and filtered shade for the rest of the day. In the afternoon, 3pm and later, your vine will be in the middle of the majority of the shade your awning provides.
Other plants this method works for (in zone 9A):
- Zucchini (and other forms of squash)
- Chiltepins (and all other peppers/chilies)
Using a tree is the most cost-effective solution, but nothing beats the control you get with shade cloth!