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?
17 Comments
Corrina
March 11, 2021 at 9:43 amI have been of the dirty pot camp. But this year lost over half of my seedlings. I did have them a bit too wet at times I think. The little seedlings seemed quite robust. But then when I transplanted into larger pots, most of them keeled over in a couple days. At that point they had good light, temperature, and air circulation and I used store bought soil. Must have been the injury of transplanting let in the microorganisms that started growing when they were too wet in the flats. But I also switched soils, so hopefully it isn’t that the soil I bought is contaminated. Oh crap I just realized when I repotted I scooped the spilled dirt from the table back in the bag, which undoubtedly included some from the flats. If it wasn’t contaminated it is now. Maybe I can just take whats on top and sterilize it in the oven. Anyway, looks like I’ll have to change camps, especially to clean these pots! If dirty pots means loosing most of my seedlings, I guess at that point it’s worth it to wash em! Tho this old timer I lived with, he used just garden soil mixed with peat for potting, but he would pour a bit of sand on top. I guess the sand would make the surface of the soil dry out fast and reduce the chance of damping off.
Kodaki
February 22, 2021 at 3:01 amI hardly ever wash my pots, but when doing so I scrub away any obvious bits. Leave the pot to soak in 3 parts water to 1 parts vinegar solution, for 5 minutes, then scrub with a rag under cold water and leave to air dry.
faiora
November 1, 2017 at 5:47 amJust a comment on bleach ratios: 1:32 and 1:9 are commonly used ratios and are actually more dependent on whether the solution is being used in an indoor or outdoor environment than anything else. The hospital ratio would be lower to prevent respiratory irritation from people exposed to the chemicals.
Also note too low OR TOO HIGH a ratio renders bleach ineffective against organisms. When cleaning mound, the solution won’t work at all if there’s too much bleach and not enough water.
Susan Rubinsky
October 18, 2017 at 2:56 amI am in your camp on this.
Linda from Garden Betty
September 3, 2017 at 5:34 amThank you Daria!
Kelsey Fast
August 17, 2017 at 8:54 pmI don’t think I’d even heard about disinfecting pots with bleach! Haha I barely clean mine up at all. I might spray them off with a hose, but that’s about it!
Linda from Garden Betty
September 3, 2017 at 5:42 amSame!
Karen Fergason
August 15, 2017 at 9:05 pmI’m with you, I just brush out the dirt (and spider webs). I’ve had some issues with seedlings damping off this season, but I think it had more to do with my soil medium and not the pot.
Linda from Garden Betty
September 3, 2017 at 5:35 amI usually find that damping off issues are a result of too much moisture or not enough air circulation… nothing that a dirty pot can cause or prevent.
LaVerne Drommond
March 5, 2018 at 10:42 pmDamping off can be controlled by a THIN, SPRINKLE of cinnamon on your potting medium. For lettuce, etc, press a row down, plant the seeds, And Tamp the soil over seeds.
Daria Ed
August 15, 2017 at 7:47 pmhaha Love your blog!
You are so lively!
Amazing job x
-Daria
Misti
August 15, 2017 at 4:19 pmMy pots are lucky if they even get all of the dirt at the bottom dumped out completely! I’m like you, overkill.
Linda from Garden Betty
September 3, 2017 at 5:34 amHaha, ditto on the dirt still left behind in my pots!
Cary Bradley
August 15, 2017 at 3:07 pmAgree wholeheartedly. Of course, if you’ve had a fungal attack of some kind, or have collected pots from unknown source, all bets are off, bleach away, or toss. I think this washing and then bleaching business hails from uptight town, and has no business playing in the dirt with me, and mine. You rock, GB! Sally forth!
jeanniebeans
August 15, 2017 at 2:39 pmI’ll also only brush pots, sometimes very lazily, and have yet to have unhappy seedlings or unhappy repotted plants! Agreed that it’s a bit too much; I focus on having high quality potting soil and good conditions to grow.
Linda from Garden Betty
September 3, 2017 at 5:33 amAgreed, it’s all about good soil for me!
Trixie Reichardt
August 15, 2017 at 5:50 amAs a Master Gardener in Training, I have also been told to wash pots thoroughly and disinfect using a diluted bleach solution. However, in my own garden, I have started to relax a bit and am now just giving pots a rinse in warm water, perhaps a scrub if there is any caked-on dirt, and that’s about it. Saves a ton of time and I have seen no ill effects as of yet. For commercial operations, I can definitely understand that it may not be ideal to chance it.