Home & Garden Columns
Watering plants in containers is both easier and harder than it seems. Everyone has a vice about this, generally a tendency to either overwater or underwater. (If your tendency either way is impossible to reform, you might consider underwater plants. Go on over to Albany Aquarium on San Pablo Avenue just north of Solano and have a look at some nicely planted tanks first.)
Overwatering does not mean adding too much water at one time; it means watering too frequently. If your planting mix and pot together have decent drainage, any excess water will run through and the plant’s roots will get access to the air they need in due time.
If you water too often, though, roots will stay soggy and ultimately rot and/or drown. Fungi are pretty much ubiquitous and will show up in even “sterile” (usually just pasteurized, which is quite good enough) potting mixes because their little bitty spores are part of house and general urban dust.
In fact, if you want to give yourself the heebie-jeebies, do a bit of research about what’s floating around us all the time. You’ll never trim your nose hairs again. Ever think about where the rubber is going as tires are wearing out? Uh-huh, you’re soaking in it. And spores of all sorts, mineral particulates, industrial outfall, pollen, little bits of dead bugs et alii, dander, shed skin cells, the excretions of dust mites which live on those shed skin cells… Dust mite allergies are partly allergies to the dung of those dust mites. You’re inhaling bug poo! No wonder you’re sneezing!
But I digress. (And I’m allergic.) Some fungi are a necessary part of life for many plants. The magic phrase is “mycorrhizal association.” Most container plants, though, aren’t mycorrhizal associates. If you have a plant of local origin in a pot and it needs a boost, you might try a tablespoon or two of the earth from which it sprang, what the heck.
A plant that’s succumbing to the ills of overwatering will look rather as if it needs more water: leaves drooping, bits yellowing or browning off. If it actually falls over, give it a respectful burial in the compost because chances are it’s rotted right through at the root crown.
Stick your finger in the plant’s soil mix, if you want to know anything about its water. If it’s damp and the plant’s drooping, worry. I don’t mean the surface; get down to a knuckle or two below the top. If it stinks, also big trouble: stagnant water. Unpot the plant, gently shake off some of the wet soil, and repot with some new dry soil. Then vow to change your ways.
Even succulents need water in pots, but they’re most susceptible to overwatering. Again, stick that finger in. If your plant has spines or points or vegetable fangs, keep a scrap of cardstock handy to shield yourself. If that doesn’t work, consider investing a few bucks in a soil water indicator; you can probe painlessly and watch the meter.
Resource: Plant sales at Merritt College on Saturdays: Sept. 15, Oct. 13, Nov. 17, 9 a.m.-3 p.m. See www.merrittlandhort.com for updated plant lists.
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.