City of Davis

The Mediterranean climate has mild, wet winters and hot, dry summers. Our California climate can support plants adapted to this weather since ours is also considered Mediterranean. Of course, within this Mediterranean climate zone, Northern California, the Central Valley, and specifically Yolo and surrounding counties have their own micro-climates with varying temperature ranges, wind and soils which affect choices of plants. Water-wise plantings which are naturally adapted to the temperature and rain conditions of the Mediterranean and Central Valley are a perfect choice for many of our gardens.

Water-wise gardens, xeriscaping, drought tolerant, and Mediterranean all refer to gardens designed with water efficiency in mind. The term drought tolerant can itself mean a range of water requirements. Anything from moderate to low and very low water plants are considered drought tolerant. In The Sunset Western Garden Book, descriptions of low water plantings could include such wording as: "drought tolerant once established" and also "water deeply but infrequently". How much water a plant needs depends upon many factors, the first being the nature of the plant itself. Knowing the origin of the plants sometimes may help understand the requirements of the plants. For example, knowing that Interior Live Oak is native to the Central Valley will tell you the plant tolerates heat and long summers without water. Therefore, giving an Interior Live Oak too much water in the summer could be detrimental to the health of the tree. Sunset Western Garden Book may mention the origination of the tree, shrub or perennial.

Even drought-tolerant plants are affected by how well established the roots are, how high the temperatures go and remain there, as well as if the location of the plantings are in a north, south, east or westerly area. A strong wind can also have a drying effect on plants and their ability to be drought-tolerant. It is also common knowledge that the type of soils are a major factor in affecting how long a plant can go without water. Clay soils tend to hold water longer but also could retain water so that drainage may become an issue. Mulch on top of the soil is known, among its numerous positive qualities, to affect the water efficiency of plants by preventing surface water evaporation in the heat and keeping soil temperatures more moderate in the heat and cold.

Knowledge of the plant materials is very important in considering the right choice of plant for the right location. Something else to consider for water efficiency is placing plants with similar watering requirements together. Then, you can adapt your irrigation system to fit the needs of the plants. For example, many native California plants such as ceanothus, fremontodendron, or manzanita which are very low water plants should be placed together in a planting and not mixed with more water demanding plants such as roses. Many trees, shrubs, and perennials benefit in dry climates such as ours by having deep roots rather than surface roots. The irrigation used for lawns on drought tolerant plants can help to create more surface roots which are more stressed in times of extended times of high temperatures.

Fremontodendron

Ceanothus

Manzanita

This is a brief introduction to some of the considerations in planning a drought tolerant garden. There is a huge list of shrubs, trees, perennials, groundcovers and herbs that do beautifully in a waterwise garden in this climate, especially if they are arranged in an aesthetic and thoughtful manner. The look can be colorful or soothing, elegant or informal, dramatic or simple. If you are just filling in an existing landscape, or needing landscaping for a new residence, or your garden needs an extreme makeover, a waterwise garden could create the mood and aesthetic that could be lovely and suit your needs.

Cherryne Kravitz is a landscape designer in Davis, California. She can be reached at ckgardendesigns@hotmail.com.