One interesting thing to watch in the springtime is which plants start to awake from dormancy at different times under the exact same conditions. This is usually best seen in lawn areas where patches of green turf show up while there are still patches of dormant turf. Often this is because there are different types of cultivars of turf and even different species, which is close to impossible to recognize with an untrained eye.
Then there are other times where it is plain to see.
The above is a classic example of what I mean. In the picture you clearly notice two of the shrubs are fully leafing out and starting to actively grow. This row of shrubs was all installed at the same time during the construction of the Discovery Learning Center. They are obviously in the same location with the same irrigation, shade and other environmental impacts.
These shrubs are of the same species but are slightly different cultivars. This cultivar may have a slightly different genetic characteristic which is more conducive to growth at a slightly lower soil temperature. This has allowed these plants to start the spring growth much earlier than the rest of the bed. The other plants are starting to create leaf buds but are a couple of weeks behind the others. During this phase it can take on the appearance that these are the only two plants that have made it through the winter; which can cause some alarm. However, after closer inspection, the other plants are just fine they are just a little behind their brothers and sisters.
This is one interesting part of Mother Nature, such little changes can have drastic affects on the landscape and its growth habbits.