A: Well, unfortunately, most pine trees require a good bit of sun, at least six hours a day. But as luck would have it, there's one pine tree that actually requires a good bit of shade, especially in the south. It's Pinus flexilis, also known as the limber pine (figure F). A slow grower that's hardy to Zone 2, the limber pine is so named because its branches are extremely flexible. It's a nice choice for small spaces. 'Vanderwolf's Pyramid' has blue-green needles (figure G) that blend beautifully with many landscape plants.Q: What are the absolute minimum temperatures for tropical plants?
A: That's a very good question because there are no published reports on just how low the temperature can go before a tropical plant succumbs to tissue damage. By definition, a tropical plant is native to the tropics and in the U.S., that means Zone 11, which includes the southern tip of Florida, a narrow strip along the Gulf Coast of Texas and all but the mountainous regions of Hawaii.
However, outside of Zone 11, tropical plants are typically grown indoors as houseplants year round, or as container plants on the patio. And since the latter are usually brought indoors long before the first hard freeze, there's not a lot of definitive data on the absolute minimum temperatures. But interestingly, some tropical plants can survive pretty cool temperatures--several degrees below freezing.
For example, just last week, temperatures at my place bottomed out at 20 degrees, but my palms are doing fine. I admit I'm pushing my luck, so I'll bring them in soon. If you're concerned about a specific tropical plant, one that you want to successfully over winter indoors, then I'd suggest taking it inside before temperatures drop to about 40 to 45 degrees F.
Q: What's the difference between a Datura and a Brugmansia?