How do plants survive in the wild without someone watering them?

Question

I have a small garden in Seattle and as soon as summer rolls in I have to be vigilant about watering my plants or else they die. Meanwhile just a couple dozen feet from my home there's a pretty big patch of unkempt trees/grass/flowers that seems to grow just fine all summer despite anyone watering it. Same goes for the millions of plants around my state that don't need humans to grow.

But... why is this the case? Why can't my potted plants survive without water just as well as the wild ones outside? Its probably an obvious answer but I can't quite put my finger on the difference.

Answer 1

The simple answer is that the soil in your containers dries out faster than real soil, especially in hot summer. Also roots of your potted plants are limited to the container, and can't go any deeper into the ground in search for water.

However, it is a bit more complex if you compare with wild plants that grow naturally near your home or in your state. More complex because there is also natural selection going on, the plants 'survive' (or better thrive best) there, so you'll find different species in the wild than in your containers. Also they'll find a nice spot where they will have enough sunlight/shade and water (and other resources) available. For each species a certain niche is best suitable, nature in time will find those niches for the available species.

Answer 2

There are many reasons, but look the wild plant: are they the same as the plant in your garden? Do the flower at same time?

As example: orchids (usually) likes humid climate, so they grow only on such climate (and many growth just on trees). If you want orchids on your home, you need to provide the climate they expect (so usually hot and wet).

You may also notice that many wild flowers tent do blow in spring, before the hot and driest days. Or in forest (and in humid parts). There are exceptions, like poppies, but I do not find them so beautiful to replace my flowers.

We like also more exotic flowers (so not used to our climate). In addition we tend to select plants for long blooming, or large flowers, not for resistance to dry places.

As you see, there are various reasons. But you can select species which requires not much watering, just the selection will be limited. Roses are pretty resistant (but they are bushes, so with long roots). I like very much many cactuses flowers (but they tend to bloom just for limited time, and they may not like my weather). People tends also to use more plants for the leaves (bushes, or in any case perennials, so with deeper roots, or also sedges and decorative grasses). Or you can select some other species, like poppies, sunflowers, etc.

So: few species are adapted to your climate, you have a limited choice, and people like something different than usual wild plant they see at border of streets.