by Sandy Swegel
One of the most popular mixes of wildflower seeds that we sell is the Drought Tolerant Mix. It’s a good combination of both perennial and annual flowers that can handle some stressful situations and still make beautiful flowers.
Growing drought-tolerant plants may be different than gardening the way most of us are used to. While supplemental water is helpful during germination and the early growth of the plant, too much water will most often cause the plants to have too much fast green growth that is weak. A heavily watered drought-tolerant plant will often produce few flowers and in rich moist garden soil can simply rot and die.
Understanding what it is that makes plants “drought tolerant” may help you understand better how to care for the plants. Even drought-tolerant wildflowers still need water to thrive, (they are drought “tolerant” not drought “loving”), but they have adapted to drought conditions in several clever ways.
Some plants, especially ones that thrive in the prairie, grow very long tap roots that seek out water deep below the surface. Coneflower and butterfly weed are two plants that have taproots. Dandelions too, that’s one reason they are so tough to get rid of.
Other plants learn to store water. Cacti and yucca come to mind first, but other plants that store water in the leaves are succulents like sedums or hen and chicks. Break open a leaf and gel-like water oozes out. Some sturdy wildflowers save water in their roots. The tubers that Liatris makes are a good example.
A common adaptation to drought has been to conserve water by limiting the amount of water the plants lose to the air. Plants typically lose water through their leaves, so drought-tolerant plants will have leaves that conserve water…by having narrow leaves like penstemon, or hairy leaves such as lamb’s ear. Other plants have silver or bluish leaves that reflect back the sunlight. Desert marigolds conserve water this way.
Once you understand how the plants are holding onto water, it makes sense that lots of water would stress drought-tolerant wildflowers. They would have no way to get rid of the extra water.
Photo credit: http://www.geograph.org.uk/photo/473362