# Will minerals seep through a clay pot? **URL:** \ **Category:** Factual Questions\ **Created:** [September 3, 2005, 10:51pm UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944 "2005-09-03T22:51:45Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [September 3, 2005, 10:51pm UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/1 "2005-09-03T22:51:45Z")
I’ve got a couple of African violets growing in African violet pots – a smaller, unglazed white clay (stonewear?) pot that sits inside a larger, glazed pot. The idea is that you keep the larger pot filled with water, and it keeps the plant in the inner pot at the proper degree of moisture. Works a treat, as the Brits would say – I’ve had totally unprecedented luck in keeping African violets alive. (Well, I did manage to kill one by letting the inner pot get dry, but that was human error.) My question is: I feed most of my houseplants once or twice a month with a mineral fertilizer I put in the water that I water them with. If I put this stuff into the pot water for the African violets, will it seep through and feed the plant? ---
**Author:** ![Giant\_Spongess](https://avatars.discourse-cdn.com/v4/letter/g/94ad74/32.png) [@Giant\_Spongess](https://boards.straightdope.com/u/Giant_Spongess)\ **Post date:** [September 4, 2005, 12:55am UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/2 "2005-09-04T00:55:54Z")
It should, so long as it’s unglazed, but it would probably work better just to drop the fertilizer into the soil right next to the plant. ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [September 4, 2005, 1:00am UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/3 "2005-09-04T01:00:37Z")
It’s too strong to put on undiluted, and I’m worried about interfering with the self-watering element. (Despite my very real green thumbery, I have killed a hell of a lot of African violets.) ---
**Author:** ![Giant\_Spongess](https://avatars.discourse-cdn.com/v4/letter/g/94ad74/32.png) [@Giant\_Spongess](https://boards.straightdope.com/u/Giant_Spongess)\ **Post date:** [September 4, 2005, 1:08am UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/4 "2005-09-04T01:08:00Z")
Well, I didn’t mean put it on undiluted! But yes, as any museum curator can tell you (damn efflorescence) clay is quite porous so the stuff ought to seep through, the only thing to be mindful of is the soil right next to the pot walls will trap most of it. ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [September 4, 2005, 1:13am UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/5 "2005-09-04T01:13:29Z")
Obviously it’s porous to water – I just wasn’t clear whether it was porous to other stuff in the water. ---
**Author:** ![Giant\_Spongess](https://avatars.discourse-cdn.com/v4/letter/g/94ad74/32.png) [@Giant\_Spongess](https://boards.straightdope.com/u/Giant_Spongess)\ **Post date:** [September 4, 2005, 1:44am UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/6 "2005-09-04T01:44:45Z")
Well, I’m pretty sure you’ve seen pots with white crusty stuff on the surface. That’s calcium and other minerals that have leeched through the clay (hence my efflorescence comment). ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [September 4, 2005, 2:45am UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/7 "2005-09-04T02:45:14Z")
It’s the crusty stuff that made me ask – usually that’s heavier on the inside, which would seem to indicate that the minerals stay behind when the water goes through. (I’m coming across as very argumentative here, aren’t I? Sorry about that…) ---
**Author:** ![Giant\_Spongess](https://avatars.discourse-cdn.com/v4/letter/g/94ad74/32.png) [@Giant\_Spongess](https://boards.straightdope.com/u/Giant_Spongess)\ **Post date:** [September 4, 2005, 7:38pm UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/8 "2005-09-04T19:38:22Z")
Well, I did say that it would probably be better to just put the fertilizer in the soil. Undoubtedly some of it would get through the clay into the soil, but how much would reach the plant is uncertain. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [September 4, 2005, 8:11pm UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/9 "2005-09-04T20:11:59Z")
I don’t think that a once-every-two-weeks-or-so top watering with the diluted fertilizer would adversely affect the plant. And it’s not like you’d have to soak the soil with the top-watering…you just want to get the fertilizer in. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [September 4, 2005, 8:13pm UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/10 "2005-09-04T20:13:06Z")
Also, you could try the fertilizer sticks that you just push into the soil. The problem with them is really localization…the side of the plant that’s near the stick gets far more fertilizer than the other side. I don’t really know if that’s a huge problem, though. ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [September 5, 2005, 2:26am UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/11 "2005-09-05T02:26:59Z")
Okay, thanks, guys – sorry to be such a PITA about this – I’ll try the top watering thing. ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [September 5, 2005, 2:39am UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/12 "2005-09-05T02:39:32Z")
> [@twickster](#): > > Okay, thanks, guys – sorry to be such a PITA about this – I’ll try the top watering thing. _tries to figure out where **twickster’s** been a pain in anyone’s tuchus_ Don’t worry about it. I know how nervous-making it can be when you aren’t sure if a prized plant can handle what you’re about to do. ---
**Author:** ![twickster](https://avatars.discourse-cdn.com/v4/letter/t/ec9cab/32.png) [@twickster](https://boards.straightdope.com/u/twickster)\ **Post date:** [September 5, 2005, 1:04pm UTC](https://boards.straightdope.com/t/will-minerals-seep-through-a-clay-pot/319944/13 "2005-09-05T13:04:48Z")
I felt like I was saying nothing but “yeah, but…” I’m just nervous about top-watering; since the thing that’s working for me is letting these pots do the watering, I don’t want to risk effing things up by inserting myself into the system. I’d been putting the food into the pot water, but it suddenly occurred to me that that might not be having any effect. Oh well, a little careful feeding once a month should be okay. **crosses fingers**