Shop Products
Houzz Logo Print
maca9

5-1-1. Perlite size and watering?

maca9
10 years ago

Hi All

Thanks to this forum and the helpful advice of its members I've recently moved my few potted citrus to Al's 5-1-1 mix.

The perlite I have used is coarse perlite and most of it it is approx 1/5 to 2/5 of an inch in size. I have seen from many of the discussions that this is too large for the true gritty mix. However it appears that for both the bark and perlite the size is more forgiving in the 5-1-1 mix. Is this correct?

I say this because the 5-1-1 discussions seem to say that any bark up to 1/2 inch is fine. (Fine particles to 1/2 pieces). And for the perlite simply "coarse" is all that is stated.

My second question is around watering.

Do I need to wait until the mix is "dry" before I water again. Or is it ok to keep the mix "moist" by watering every few days before the dowel or finger test shows totally dry mix?

I understand over watering is a problem for root health but the drainage qualities of the 5-1-1 would likely eliminate this risk?

Thanks for all the help.

Cheers

Macca

Comments (15)

  • nil13
    10 years ago

    That perlite sounds fine for the 5:1:1.
    If I'm growing something that needs the medium to dry out, I won't generally put it in 5:1:1. I'll use something like gritty or missouri gravel bed, maybe straight pumice. i'd keep citrus pretty well watered.

  • maca9
    Original Author
    10 years ago

    Thanks Nil13. Appreciate the input.

    So straight pumice for citrus as an option? That's interesting. Has anyone tried this with success?

  • nil13
    10 years ago

    That's not what I meant. Although it is certainly possible. Damn near anything can be grown hydroponically. I was talking about cacti or dryland plants that appreciate drying out.

  • Sugi_C (Las Vegas, NV)
    10 years ago

    I'm curious about this, too. Came by today just to ask this question so I guess I'll just tack onto your thread. :-)

    At the hydroponics store, I saw this amazingly enormous perlite. Given how much I screen the perlite I have right now, and how little of it remains afterwards (1/4" screen but I'd say it's more accurately 3/16") -- I was intrigued by this gigantic perlite. Each piece must be about 1/2" (give or take, with many of it bring even larger!) with no dust or crushed junk.

    1. Is this suitable for 5:1:1? I am out of perlite now and need to go buy more and wanted to buy this type but I'm not sure if it's adequate for my container needs.
    2. If it is suitable, or ideal -- given the larger amount of pockets when I take a cupful of this vs. cupful of the crappy perlite -- do I adjust?

    Or is this of no use to me?

    Who knew there would come a day when a bag of perlite fascinates me....

  • tapla (mid-Michigan, USDA z5b-6a)
    10 years ago

    If you were using it in the gritty mix, you'd want it in the same size range as the Turface & grit - about 3/32-3/16.

    In the 5:1:1 mix, the perlite gets settled between the flat pieces of bark, and makes some nice vapor-filled macropores. That doesn't happen in soils based on fine particles, like peat/compost/coir/sand ..... The particles simply surround the perlite, no matter what its size, so the primary function of perlite in soils with large fractions of fine ingredients is to reduce water retention - it does little for drainage, aeration, or reducing the ht of the PWT. I'd say the ideal size of coarse perlite for the 5:1:1 mix would be 5/16".

    Al

  • maca9
    Original Author
    10 years ago

    Sugi C - haha. I totally agree. Never thought the size of perlite would be of such interest to me either!

    Thanks Al. As always its great to get specific advice from you on the components of the various mixes.

    Any thoughts on the pumice only suggestion for citrus?

  • Sugi_C (Las Vegas, NV)
    10 years ago

    Back to screening for me then! Thank you, Al!

    Maca--the perlite was beauuuutiful! :-D But it is really large. Large enough that I hesitated to buy it and actually didn't so I could ask first. Ideally, while this was labeled "large", I'd like to find a bag of medium that is so uniformly true perlite rocks throughout without so much crushed rocks or dust.

    The search continues....

    Grace

  • tapla (mid-Michigan, USDA z5b-6a)
    10 years ago

    Pumice only should work ok for about anything you want to grow in it. It doesn't hold onto water or nutrients particularly well, so given my druthers, I'd stick with the gritty mix.

    Al

  • nolerad
    10 years ago

    Al --

    I'm confused by this: "I'd say the ideal size of coarse perlite for the 5:1:1 mix would be 5/16"."

    Is there a typo here, or are you saying use a mixture of 2 different size (small and large) perlite particles? Thanks for clarifying.

  • oxboy555
    10 years ago

    1/4" to 3/8" is my sweet spot for perlite.

  • tapla (mid-Michigan, USDA z5b-6a)
    10 years ago

    It should have been >1/10 and Sorry about the mistake - good catch! It shows you're paying attention. ;-)

    Al

  • nolerad
    10 years ago

    Thanks, Oxboy555 and Al... much appreciated! I look forward to the results achieved using the 5-1-1 mix.

  • tillygrower
    10 years ago

    If I purchase coarse perlite, a lot of it seems greater than 5/16th in diameter. For the 5-1-1 mix, should I just stick with the "regular" size perlite?

  • tapla (mid-Michigan, USDA z5b-6a)
    10 years ago

    Use what's available in big bags and what's cheapest. The last 4 cu ft bag I bought was medium in size & came from a 60 cu ft bag that was 'stuck' to a pallet and only cost $10 wholesale.

    Al

  • tillygrower
    10 years ago

    Thanks, Al. That makes it easy.