What I’m about to say goes against traditional wisdom that’s ingrained in nearly every gardener and written about by many a cooperative extension office, but I’m bringing it up to ask a simple question: Why?
Why do we need to wash our dirty pots before starting seeds or putting plants in them?
I confess that I haven’t washed my pots in over seven years, at least not in the way that’s usually advised. Consult almost any gardening guide and the instructions often include scrubbing the pots with soapy water and disinfecting them with a diluted bleach solution.
But I, on the other hand… I am firmly in the brush-off-the-dirt, wipe-off-the-gunk camp of pot cleaning, and I stack my pots in the potting shed like this, ready for the next round of seedlings. (This is the brush I use, which makes quick work of seasonal clean-up, though any stiff bristle brush will do.) Occasionally I hose them off to remove any stubborn and particularly crusty bits, or I wash the pots for aesthetic reasons (mostly for gifting plants to friends).
I’ve amassed a towering collection of seed starting pots, gallon pots, six packs, and seed trays over the years that continues to grow, and I can’t imagine hand-washing (or even hand-soaking) every single one of them at the beginning or end of each season. It seems like a silly waste of effort for not that much benefit. Why, then, are we told to wash our pots at all?
From what I’ve gathered, washing pots supposedly reduces the chances of damping-off disease. Washing pots prevents pests, fungi, or bacteria from hitching a ride on your new plants. Washing pots is a part of good plant health management. All valid reasons, sure, but none that can justify the colossal pain in the butt of washing a pile of pots in the sink, two or even three times when all is said and done.
While pests and diseases can certainly transfer from an old plant to a new one, the chances of that actually happening are slim. There may be the rare occasion that a dirty pot harbors root aphids lurking in leftover soil or spider mites hibernating under the rim, or perhaps a plant you tried to grow in the pot was plagued with allium rust or clubroot.
If any of that were the case, and serious enough to warrant consideration at all, I wouldn’t bother with washing and disinfecting that pot. It’s far more economical to throw it out and use a brand-new pot. The time saved and peace of mind earned is worth the couple extra bucks to replace it. (Not to mention, the common advice of using a 10 percent bleach solution for disinfecting — a dilution of 8000 ppm, or parts per million, more than even the disinfectant level recommended for hospital settings — is insane and sounds like overkill to me.)
As for terra cotta pots: Salts and other minerals that build up on the outside (usually at the base, and caused by fertilizers or hard water) can be unsightly and can sometimes hinder proper drainage if left to accumulate, but those are about the only reasons you’d need to scrub and wash them. The fear of disease running rampant among dirty pots is really, truly overblown.
When you think about how plants are grown in their natural environment — outdoors, in the elements, with no coddling from us gardeners — they’re exposed to all the insects and microbes that were there before. Thus, plopping a seed or plant into a dirty pot is no different than plopping it into, well, soil. And how often do you see damping-off in your garden?
Susceptibility to pest or disease is more an unintended outcome of our own tendencies (to overwater, underwater, sow too soon, over-fertilize, or perform any number of other simple mistakes) and less a direct result of secondary infection from a dirty pot. Viable seeds raised under good conditions (where light, moisture, and air circulation are concerned) produce plants that are vigorous enough to withstand your garden-variety microbes.
This is not to to say I advocate poor hygiene or shoddy maintenance when it comes to your tools and equipment. Proper care of pots and other gardening gear goes a long way toward maintaining longevity and sparking joy when you see everything all clean and orderly. But the advice I constantly read about washing and disinfecting your pots seems like a gardening myth that’s oft repeated but lacking in scientific basis.
What are your thoughts? Are you a devoted pot washer, or merely a dirt brusher like me?