Home & Garden Columns

Garden Variety: Water, Water Everywhere — Or Not

By Ron Sullivan
Friday September 28, 2007

One of the limitations, frustrations, confusions, and overall learning experiences any gardener encounters here is water. Understand that I use “learning experience” as an expletive.  

Container gardens are infamous for testing a plant’s tolerances and a planter’s luck and skill with regard to water. Houseplants are chronically overwatered except when they’re underwatered. An overwatered plant can look a lot like a thirsty plant when it’s in the process of succumbing to some wet rot or other. Man, you can’t win.  

Outdoor planting here is equally water-weird. A Mediterranean climate like ours has a few salient characteristics, and a prominent one is that it doesn’t rain all summer. This is quite a challenge for a plant trying to make a living: drought during the season when the days are longest and the light to grow by is most abundant.  

Look at plants native here, and to other such places like South Africa, coastal Australia and Chile, and of course the coast of the Mediterranean. Lots of them, counting numbers of species as well as populations, are annuals. They start growing as soon as the soil warms and the sun-time increases in spring, flower and reproduce and scatter their tough seeds by midsummer, and die when water gets too scarce.  

Perennials including trees get seriously stingy about water. They grow silver or succulent or tough-hided foliage, imbue it with (often fragrant) oils to help retain moisture; they drop their leaves and retreat into wood, like buckeye, or underground storage, like most of our gorgeous bulbs, by summer’s end. If they’re holdouts from a wetter era like redwoods, they learn to sieve water from the ocean fogs and drink that all summer, sustaining their understory neighbors too.  

One way to improve your luck is by knowing what your plant is and what its needs and tolerances are. “Tolerance” in plantspeak is some condition—low light, wet or alkaline or heavy soil, wind—a plant doesn’t like but will survive. If you have the plant already, you’ll want to give it what makes it thrive if you can, or at least opt for something it will tolerate. If you have the place and are looking for a plant to put in it, look for one that will like what you have to give. 

It’s getting close to planting time for natives (and other Mediterraneans). If you have decent drainage, which for most of us means some slope or berms or lumps in the yard, you can plant natives like Fremontodendron or those bulbs, Calochortus, Brodiaea and the like, that are not only drought-tolerant but drought-demanding. If they get irrigated in summer, they’re susceptible to fungus rots that multiply in warm, moist soils.  

There’s the rub: Most garden plants, native or no, need help at least through their first summer. That’s a bit of suspense we just have to endure: is this infant dying of too little water or too much? If you’ve put plants with similar needs together, it’ll be easier to cope with this, to guess whether they’re all thirsty or not.  

How? More next week. 


Ron Sullivan is a former professional gardener and arborist. Her “Garden Variety” column appears every Friday in East Bay Home & Real Estate. Her column on East Bay trees appears every other Tuesday in the Berkeley Daily Planet.