Watering Frequency

Nan's Nook : Archives : Botanicals : Cactus : San Pedro : Growing San Pedro             Also See: Folar Feeding
Posted by: TimothyLeary Dec 05 02, 07:37 PM GMT
how often to i water these suckers?? (san pedro)

seems like the soil gets dry daily....

Posted by: ShroomVator Dec 05 02, 07:43 PM GMT
Well - remember Tim, these are Cactus. I stick my finger in the soil about an inch in and see if its damp at all - only when it gets pretty darn dry do I water - when I do, I water well.

Just me, though - I think a lot depends on your environment.

Posted by: Malformed Dec 05 02, 08:37 PM GMT
much much better to underwater a cactus than to overwater.

Posted by: Nanook Dec 05 02, 08:41 PM GMT
In the winter, when the plants are dormant... They need little or no water at all.

If they are growing under artificial light, water as ShroomVator indicated.

In the summer, outdoors during the growing season... There is no reason to allow even the top layer of soil to dry if you used the cactus mix I worked out, and you
LIME. I keep them wet all summer long.

Posted by: TimothyLeary Dec 06 02, 02:57 AM GMT
thanks for help....

and wow, i only got replies from mods and admins!!!! laugh.gif
just an oversevation

Posted by: newman Dec 06 02, 12:54 PM GMT
OK then I have my pedro under light inside no. I just put him in a week ago, But he gets bone dry every 2 days. should I water that often?

Also he seems to be getting a bit mushy, well not as firm as it was. Kinda like an old set of boobs laugh.gif

Also he has a pup about 2" high of the top, can I just put it in soil to root ?


Posted by: ion Dec 06 02, 05:16 PM GMT
Was this pedro started from a cutting?

If so, you may want to remove the pup so as to allow the cutting the energy to root.

Soft is ok at first... it's just dehydration from being cut. If, after 4-5 weeks, it does not begin to firm up, you may have a problem.

Not good to start a cutting under lights methinks. They need filtered sun.

If it isn't a cutting, then you may have a nasty problem... or it could just really need water, but if it doesn't need water, then water will only increase the problem.

In either case, take the pup off to root on his own. Sounds like that cactus can't handle the pup right now.


Posted by: newman Dec 06 02, 09:44 PM GMT
It is a fully rooted girl. the pup grew over the summer smile.gif

It does seem to firm up a bit after a few hours post watering.
And the soil gets bone dry, every 2 days. I just was not too sure if it was cool to water it that often.

Thanks Ion, I will water it more often for a bit and see if that helps.

"Help me obewon ionoby, your my only hope"
Sorry just watched starwars biggrin.gif

Posted by: Bob Roberts Dec 09 02, 08:05 PM GMT
If your soil is getting that dry in two days, let it go dry for more days. At least a week to two, especially when rooting and depending on what type of media you are using. If you are interested in taking it an extra step, provide some bottom heat using a seedling mat or something similar with good temperature control.

There, I'm not a moderator. rolleyes.gif


Posted by: Nanook Jul 10 03, 11:57 PM GMT
I never let the soil dry out on Pedros (not if you want max growth) between waterings unless cactus are dormant or rooting wink.gif

Keep Pedros at least, damp/wet all summer. When the tops get dry, it's time to water. In a lot of places this means every day or two... At least outdoors in the growing season (now).

The best way is constant feeding... Keep pots wet with Urea spiked Peters Pro GP fertilizer is great, feed heavy on the nitrogen and water the pots every day or two. Every third or forth watering with feed you give them a break... Flush the pots with fresh water adding about 1/4 cup lime for every 5 gallons, keep it swirled.  Pots metabolize, and they leave waste salts and acids in the process: watch your pH, and water with plenty of fresh water between periods of feed, rinsing the pots. Several good fillings with some "lime water" is ideal.  If you feed heavy and let pots get hot and dry, salts concentrate and roots burn. Roots stop metabolizing when they dry out and when they overheat. Clay pots above ground in full sun evaporate, as long as water is there to cool the pots. As  the water runs out, salts concentrate, temps rise, and the roots burn.  Sunken pots (sunk into the ground up to the lips) and constant feeding, keeping roots cool and  moist makes for ideal growing conditions

Read Thru the Tek again, don't let pots dry in summer

For peak summer growing I feed with a mixture of 2 tablespoons Peter's (above) and 3 tablespoons of Urea (46-0-0) in five gallons of water. Don't let the pots go completely dry during the growing season if you can avoid it. Outdoors in many areas summer feed is supplemented with rainwater, if not give the plants a break from feed about every second or third watering… Plain water, or weak lime water once in awhile rinses out accumulating salts. Rinse the pots well with a hose or rainwater ad-lib, but keep feeding… And lime with a few tablespoons of powdered rock per pot every few months if you are feeding heavy. A word to the wise: don't feed any heavier or you will burn the roots and don't let the pots dry out and get hot in full sun if you feed heavy. Roots like it rich, cool, and moist.

If you don't have Urea, or it's too much to get a hold of (it comes in 40lb sacks), you can use up to 1 tablespoon per gallon of most any General Purpose fertilizer. If you are letting your pots dry out, use about 1/3 that rate.

Pedro roots
in the right soil go nuts with constant high nitro feed, so do the columns biggrin.gif

Not responsible for this water/feed tek if you are not using the correct soil mix

Posted by: ion Jul 11 03, 12:46 AM GMT
Remeber the axiom:

Holds air like a balloon, holds water like a sponge, drains like a seive.

If the mix is right, it drains fairly quickly, but still holds lots of water... basically it should be a bunch of tiny sponges with air pockets in-between them all.

The main thing about water (and nutrient) uptake in cacti roots is the pH... as long as the pH is right (slightly basic in this and most cases), you can't over-water during the growing season. wink.gif

I've also figured out that as long as the soil drains entirely within an hour or so, it is "well-draining" enough for the roots to get the proper amount of air... you just don't want mud.


Posted by: Voodoo Jul 11 03, 12:52 AM GMT
My soil looks like mud when I water initially, but within a few minutes its drained. Sound good? Maybe Im just soil paranoid. laugh.gif

Posted by: ion Jul 11 03, 01:09 AM GMT
Sounds good. biggrin.gif

Indeed, as the roots grow, the soil aerates further, making it drain better as the cactus ages. wink.gif


Posted by: Samsara Jul 11 03, 02:43 AM GMT
Hehe I was thinking, "What, I'm supposed to be letting my cacti dry out??" laugh.gif

Posted by: Fungusmaximus Jul 11 03, 09:16 PM GMT
If the soil is allowed to dry out, I thought this made the cactus roots grow out in search of water. Not like they travel great distances er anything just that the root system would get larger.
And a large root system aids in growth, right?

I dunno..?

FUNGUSmaximus tongue.gif

Posted by: Nanook Jul 11 03, 09:43 PM GMT
Maybe during the first 2-3 weeks of the rooting process, drying out prevents rot from setting in on rooting cactus... But rooted damp they do fine more than 9 times out of ten if you have pH balanced soil, well scabbed cuts, and never set cuttings more than 2 inches deep into the soil mix wink.gif You don't need to soak rooting plants during that first 2-3 weeks (you soak them once to settle them, then just spray mist the top of the soil when dry to dampen well) because there are no roots to take water.

But once you have roots... Soak the pots frequently, keep them wet, or the roots do not grow.

Posted by: Fungusmaximus Jul 11 03, 10:24 PM GMT
Well shite! They are gonna grow too fast! tongue.gif
They are all outside and its raining now, sooo Im already on it! wink.gif

San Pedro Grow Guide - Watering : Shroom Glossary