I have trouble understanding the "sun requirements" listed on most websites. I have a flower bed that's full sun in spring, part sun in summer (under crepe myrtles) and mostly shade in fall? Most of my beds change lighting throughout the season because the sun is moving east to west in front of my south-facing house. Does that make any sense? Does that mean I have to change my entire garden each season?
How do I shop for plants under those circumstances?
It certainly does make sense. It's a problem many of us face, whether we recognize it or not. As the seasons change, so does the placement of the Sun in relation to us (really, the Earth in relation to the Sun), mostly a north-south movement. In the middle of summer, my back yard gets full sun most of the day, as the sun is almost directly over me. In the winter, the Sun is further south, and I have a LOT more shade due to some pines and some oaks that take their time about losing their leaves, on the other (south) side of my fence. The best I've been able to figure is that most of the light requirements are for the growing season for the particular plant. For most plants, that's Spring/Summer, and some go on into Fall. I'm no expert, but that's how it seems to work for me.
By the way, welcome to the garden! Glad you found us! (And you'll probably find that TX gardening conditions - especially along the upper Gulf coast - are very much like LA's conditions!)
In our hotter climate, I find that I have to worry more about the summer heat than other factors. Unless the plant is a real heat lover, it probably benefits from some light shade during those hot summer days. Many plants can handle more shade when they are not actively growing or not as active. There are also many intensities of shade. You mentioned flower beds, but are your plants mainly annuals, perennials, bushes, a mix? I saw your other thread. I recommend two books for you. Neil Sperry's Complete Guide to Texas Gardening and Sunset Nationa Garden Book. I prefer the latter. Texas A & M publishes oodles of articles that you might find interesting. Take advantage of your local extension agent, too. Let me know if you need more help.
Danika, it's not a dumb question at all. We all face that problem. For instance, I've got a patio with a white rock wall separating our patio and the neighbors patio. There is no garden earth surrounding any of the patio so it's just the near white rock of the building as well as the patio tiles and the separating wall surrounding that area. In summer it is brutal with reflective light and a lot of direct sun. Plants have to be able to take a lot of hot bright sun to survive there. Cactus and succulents are the only things I've found to survive there...so it's become my succulent collection back there LOL. But in late fall-early spring the sun is in a different position in the sky and that area gets very little direct sun...just open bright shade...on top of that we have all of our rainfall in winter so that means many many many days of no sunshine at all. It's a challenge to bring my plants through the long wet winter without them all drowning. I've found though that the winters are less of a challenge than the summer heat. So for that particular area, I keep the plants in raised pots so they can drain freely and never become water logged. They don't like the "no sun" but they tolerate it.
Other areas of my garden are much much harder to deal with as they get sun at just the wrong times in summer (2 hours in late afternoon...so partial shade plants can still wilt or burn in that intensely hot afternoon summer sun). But there are things that can be done about any area. You just have to tackle all the issues surrounding each individual bed and find plants that will work in those conditions...or artificially alter the conditions.
For example, one bed around my front patio gets that late afternoon sun, but no sun for the rest of the day. Sun loving plants don't do well and just creep out over the patio in search of sun away from the shade of the tree overhead. Fuchsia and Kalanchoe blossfeldiana don't like the few hours of afternoon sun though. So I've placed the patio furniture in such a way as to make that afternoon sun more filtered. And so far it works. Another trick is to put sun loving plants in pots on the patio in front of the shadier plants. The sun lovers will get partial sun filtered through the outter crown of the tree above most of the day and they'll take the brunt of that afternoon sun that the shade lovers can't tolerate. That has also worked well for me in another spot.
I agree that the sun requirements are for the growing season. So I wouldn't worry about a summer grower not getting much sun in winter. It will bounce back and be fine once the spring and summer sun start shining on it again.