UNITED STATES—One of the most important differences between plants and animals is that animals are ‘animated’, and plants are not. Aquatic plants might float about, and might even drift into more favorable situations. Vines and plants with creeping rhizomes can likewise relocate. Otherwise, most plants are confined to the same locations where they grew naturally, or where they were planted. They need to get it right from the beginning.
Most landscape plants that are commonly available in local nurseries are fortunately suited to local climates. A few tropical plants that prefer milder climates, as well as a few plants that prefer cooler winters, can be found; but most plants that prefer other climates are simply unavailable here. Yet, even within their preferred climates, the many diverse plants in our gardens are affected by many other environmental factors.
Exposure is nearly as important as climate is. Some plants need to be completely exposed, while some prefer shelter from heat, cold, wind or sunlight. It all depends on how they live in their natural environments. Some naturally live out in the open. Others live in dense forests, where they need to compete with other plants for sunlight. Even if we do not know where our plants come from, we should know what they require.
Japanese maples are understory trees that naturally grow in the partial shade of larger trees in mixed forests. Some types can do well in full sun exposure, but are likely to get roasted by reflected glare, or dry wind. Lace-leaf Japanese maples are more sensitive to exposure, so prefer partial shade in the afternoon, and shelter from wind. However, too much shade compromises foliar color of the red and bronze leafed types.
Most cacti and some types of yucca are just the opposite. They naturally live out in deserts, without any significant competition. In home gardens, they will lean away from shade. Knowing what plants want helps to find the best exposures for them.
Here on the West Coast of California, most of us know goldenrod only as a color of crayon. In most other parts of America though, it is a common wildflower that is colorful enough to be popular in home gardens. Yet, with more than a hundred specie, it is hard to say exactly which goldenrod, (Solidago spp.) the crayon color corresponds to. All are some shade of gold or yellow, but some are a bit more orange than others.
Most varieties of goldenrod that are available locally bloom in late summer or autumn. Some are still blooming prolifically now, on seemingly overloaded stems that stand taller than two feet. Shorter types that get only a few inches tall are probably unavailable. Perennial rhizomes spread slowly but surely, and can be divided to propagate new plants. Goldenrod needs full sun exposure, but not much water once established.
The blooms of goldenrod are just as interesting physiologically as they are colorful. The floral trusses of the most popular types are somewhat conical, but arching from their own weight. Each of these trusses supports a profusion of minute daisy-like flowers, which are actually composite flowers comprised of even smaller and more abundant florets! Bees and butterflies really seem to appreciate the floral redundancy!