Home & Garden Columns

Glenn Keator talked to the Merritt College Aesthetic Pruning Club’s annual symposium last week about planting in containers, and here are some of the things he said and evoked: 

Container planting is great in urban spaces where there’s no room for a conventional garden or access to the dirt. It’s also a good way to dress up a dirt garden: a container plant can call attention to a spot, or can be displayed when it’s in bloom or in season and then moved offstage afterwards.  

Container planting can be used to solve—even if temporarily, still usefully—difficulties posed by soil deficiencies like intractable clay or hardpan. You can have plants to enjoy or harvest while you work on drainage or toxicity problems.  

Container plantings are also portable, a great thing if you’re in a temporary housing situation whether renting or in a dorm.  

That’s also an advantage because you can move the plants to take advantage of sun as the seasons change, or to shelter tender plants using the eaves and thermal mass of a building when we get the odd 30-degree Fahrenheit spell in January.  

Another speaker noted that one can use container plants in some situations as a privacy screen to turn an otherwise visible deck into a personal solar-powered spa-lette to eliminate tan lines for an arguably special occasion.  

I myself must disrecommend this stratagem in particular to anyone who is as melanin-challenged as I am, as I am reaching the stage of having little bits of myself whacked off between semiannual skin-cancer checkups.  

I must also note that that speaker has not so far demonstrated the reported effects to any neutral third party, as a truly scientific finding would require. Not that I’m volunteering. 

Container gardening has some rules that differ greatly from dirt gardening. 

First: Don’t just dig up some dirt from the yard (or take some from a handy construction site) to fill your pots. Native soil, especially in most of the Bay Area, just doesn’t work for potting; it’s too dense and sticky. Seems a shame not to use all that free dirt, but there it is.  

You need what’s called a “soilless mix” or just plain “potting soil,” available in sacks at nurseries and variety stores like Long’s on Broadway.  

This stuff is theoretically nearly sterile, at least pasteurized, so it doesn’t foster pathogens like some fungi that attack potted plants and won’t have plant-eating nematodes and such annoying inhabitants either.  

Plants in the ground are susceptible to these too of course, but there’s something about being pent up in a container that concentrates the forces of plant-preying evil. 

Part of that something is drainage, which soilless mixes are designed to improve. They’re mostly larger particles than our clay. (Clay has particles so fine they trap water in the spaces between them, by the functional equivalent of surface tension.)  

There are plenty of brands to choose from, most roughly equivalent. Keator did have an unkind word for American Soil’s private mix, in which he has found big ol’ clay lumps.  

More about containers next week.  

Ron Sullivan is a former professional gardener and arborist. Her  

“Garden Variety” column appears every Friday in the Daily Planet’s  

East Bay Home & Real Estate  

section. Her column on East Bay 

trees appears every other Tuesday  

in the Daily Planet.