Which plant, which mix?

Jim Gerstorff
last month

Has anyone ever put together any type of list to designate which plant gets the 5-1-1 mix & which get the gritty mix?
I'm actually awaiting the postman arrival with the rest of my ingredients to mix both of these up.
I've been having a terrible time with root rot in my monsteras, pothos & philodendrens specifically.
I think I've got it narrowed down to the commercial soil I've been getting from a semi-local greenhouse I do business with.
I want to move most of my plants to these mixes but don't have a clue which one gets which mix. I have around 65-70 different kinds of plants to figure out who gets what.
Are there any "rules" for lack of a better word, or recommendations on this matter.
I'm really tired of losing my prized plants to root rot right when I think I'm doing everything right & they're looking so good!
I found it purely by accident this time & was able to save all plants involved. I think.
Thanks & God bless. Jim

Comments (14)

  • Jim Gerstorff

    I guess I need to say hello as I'm new to houzz. Been reading some stuff on here for a while now but decided it was time to join.

    So, hello everyone!


  • junco East Georgia zone 8a

    I'm sure some of the more expert members will be along later. In the mean time, I use the 5-1-1 mix only and my house plants, including many pothos and philodendrons, love it. When I pot up a cactus or succulent, I just add more perlite.

    Good luck!

    Jim Gerstorff thanked junco East Georgia zone 8a
  • gardengal48 (PNW Z8/9)

    I too use the 5-1-1 almost exclusively, both for indoor and outdoor container plantings. The only exception is for cacti and succulents and that's a custom mix created and sold by a local specialist vendor of these plants. It is closer to the gritty mix but not identical.

    And welcome to the forums!!

    Jim Gerstorff thanked gardengal48 (PNW Z8/9)
  • Jim Gerstorff

    Ok that makes things a lot easier if most all houseplants can go in the 5-1-1 mix.

    I've got a couple fancy pants philo's coming in a couple days & I was trying to figure out which mix to use. I guess they'll go in the 5-1-1 mix too.

    Thanks so much!


  • Karen S. (7b, NYC)

    I don't use either of those mixes, I'm more C&S mix & Perlite or Pumice. I wanted to suggest that Pothos doesn't really need either of those, just C&S mix w/Perlite to ensure fast drainage.

    Side Note: I tried gritty mix a few yrs.ago, didn't care for it. Had been given someone's gritty mix who didn't care for it either. If you're in the NYC area & would like several lb cans of gritty mix, pls. send me a note thru the "Message" facility.

    Jim Gerstorff thanked Karen S. (7b, NYC)
  • junco East Georgia zone 8a

    Karen--you are approximating the 511. Your C&S is probably a better quality potting mix than usually found. The goal is a well draining mix that allows oxygen to stay in the soil and helps prevent root to.

  • Jim Gerstorff

    If everything can go in the 5-1-1 mix, I probably won't use the gritty mix either.

    In the 5-1-1 mix, can pumice be substituted for the perlite? What are the pros & cons of doing so? The only reason that I ask is I've got a large bag of course pumice sitting here & I won't have my new bag of perlite until next week.

    And as far as watering goes, I can't use the usual methods to determine when to water & it seems you could actually water almost every day & not hurt anything in the 5-1-1 mix. I'm probably going to have to learn to water on a schedule.

    Here's my question concerning that. I know all plants are different but if there were some kind of average or middle ground, at what interval should you water so that your not watering to soon & wasting water that the plant is not or can not use yet? Does that make sense? If I water my monstera d. on Monday & it won't or can't use any more water until say Friday, if I were to water it on Thursday, I would essentially be wasting that water & fertilizer. That is probably as clear as mud?



  • junco East Georgia zone 8a

    Why can't you use "the usual methods" ? I've learned here on GW about using chopsticks to stick way down in the pot to see if the soil is still moist. I check my plants every 7-10 days, but don't water if the chopstick comes out moist.

  • gardengal48 (PNW Z8/9)

    Jim, provided the sizes are comparable - and both come in a range of sizes - perlite and pumice are almost interchangeable in a potting mix.

    " it seems you could actually water almost every day & not hurt anything in the 5-1-1 mix. "

    I'm not sure where this idea came from but it is most definitely NOT true!! You might be able to get away with that in a gritty mix and especially outdoors in summer but the 5-1-1 will always have a perched water table that will only increase with any daily watering. Put another way, the 5-1-1 is much too water retentive to deal with any daily watering!!

    No watering 'schedule' - ever! Water only when needed and junco's chopstick reco (aka a "tell") is an excellent method of determining when to water. Providing water when not needed is a guaranteed trip to root rots!!

    Jim Gerstorff thanked gardengal48 (PNW Z8/9)
  • Jim Gerstorff

    Well I suppose I got that idea from reading a post from someone who didn't what they were talking about. I thought the 511 mix didn't retain enough water to worry about root rot. That's also why I thought the "usual" methods of determining when to water wouldn't work with the 511. Maybe it was the gritty mix they were talking about. Either way I'm glad that has been clarified! I sure don't want any more root rot issues.

  • Dave

    Jim, you’re getting the gritty mix and 5.1.1 confused. Gritty holds a lot less water.

    5.1.1 you still have to be careful and check before you water.

    with 5.1.1, outside in the direct summer sun, there were some hot days that I was having to water daily.

    inside during the winter, it’s more like weekly.

  • junco East Georgia zone 8a

    Dave--I have the same situation in the summer with outside pots. For those I mix the MG potting soil and soil conditioner 50/50 and that helps.

  • tapla

    Soils that hold perched water are inherently limiting, because, as long as perched water occupies a fraction of the medium, it limits oxygen availability, which in turn limits root function and can kill fine roots. This can and does occur when perched water is in play, even if the plant appears perfectly healthy. Lack of oxygen can quickly kill the finest roots, which are the roots that do the lion's share of the work. This triggers chemical messengers that signal the plant to stop putting on top growth until the damage to roots is repaired. When this occurs in cyclic fashion, the loss of potential can be very significant, even if the plant appears healthy. The average grower is usually content if a plant appears healthy, but it's still good to know that, even though loss of potential is very often inconspicuous, inconspicuous does not equal nonexistent. As you might imagine, the longer the plant has to endure the periods of saturated soil, the greater the loss of potential and the more conspicuous the manifestation of trouble in the root zone becomes, in terms of the plant's appearance.

    The gritty mix is purposely designed to be flexible in how much water it can hold while still not holding any significant amount of perched water. This, because it holds (nearly) all of its water within internally porous particles (Turface/bark), on the surface of all soil particles, and at the interface where soil particles contact each other; whereas, media that have significant variation in particle size and include a significant fraction of fine material, can/do hold a significant amount of water in the small spaces between particles, that, when the soil is dry, are occupied by air. That is the water that robs plants of their potential.

    That said, I don't think anyone really cares what path a grower chooses insofar as what their chosen medium provides in terms of the length of appropriate watering intervals. Information is provided to help people understand the impact water retention has on vitality/growth/yields/......, and to help them get more from the growing experience if their nurturing bone needs a better workout.

    I want to circle back again to the idea of lost potential and provide some supportive perspective. Because I'm fairly well known to the gardening community in mid-Michigan, I have a good number of people who call on me for help with their plants - both woody plants more herbaceous houseplants. I get to see, close up, how much potential can be lost because of any limiting factor. There is no doubt it's possible for issues related to root health to rob more than 100% of the plant's potential for growth and vitality. Plants are shedding organisms, and growth is measured as an increase in the weight of a plant's dry mass. Unless cultural conditions allow a plant to create more food/energy than required to to keep it's systems orderly, they cannot grow. In fact, if they use more energy than they produce, they shed parts. Even conspicuous extension growth in stems/branches/roots, or multiplicative growth of leaves and/or branches cannot be considered to be 'growth' if the dry weight of organs the plant sheds is greater than the dry weight of new leaves and branch/stem extension.

    There are many factors that can affect a plant's
    ability to grow to its genetic potential. Some might have might have notice my regular
    use of the term 'vitality' when I write. It is actually a
    plant's vitality that we hold any sway over, not its vigor. 'Vigor'
    is a constant. Mother Nature provides every plant its own,
    predetermined level of vigor by programming it into each plant. Vigor
    is the genetic potential every plant is encoded with, and the measure
    of vigor is the plant's ability to resist stress and strain.
    Vitality, in contrast, is variable - a dynamic condition that is the
    measure of a plant's ability to cope with the hand it's dealt,
    culturally speaking. A good way to look at the difference between
    vigor and vitality is to look to genetics for the level of vigor and
    to things cultural for the plant's vitality. It's up to us to provide
    the cultural conditions that will ensure our plants' vitality. Vigor
    and vitality are distinctly different, and a good case could be made
    that they are unrelated, but there is no need to delve deeper into
    that point. A plant can be very vigorous and still be dying because
    of poor vitality. Far more often than not the term 'vigor' or
    'vigorous' is misapplied, where in their stead the terms 'vital' or
    'vitality' would have been more appropriate. Reduced vitality is what
    we witness when our plants are growing under stress or strain due to
    the fact they are being asked to grow close to or beyond the limits
    they're genetically programmed to tolerate.

    The paragraph immediately above was a lead-in to the following point. Some books and literature tend to leave those of
    us who grow plants in containers impressed with the notion that the
    overwhelming % of plants are so individually different that they each
    need a care regimen unique to and designed specifically around each
    species. The fact is, a very high % (nearly all) plants commonly
    grown as houseplants (excluding cacti and those succulents that
    require or respond best to long periods between waterings during
    known intervals of the growth cycle) do best under nearly the same
    set of conditions. IOW, what is required to optimize vitality/growth
    is nearly uniform. It's the plants' ability/inability to tolerate
    extremes that has the most significant affect on vitality/growth.
    Plants are genetically encoded with a measure of vigor that is
    constant. Vitality (roughly health), OTOH, is a measure of how well a
    plant tolerates the cultural hand it is dealt, and that's on us. Some
    plants tolerate wide variance in cultural conditions because they are
    very vigorous, while their not so vigorous counterparts might insist
    on more exacting parameters if they are to perform well in

    It's not that plants vary so much in terms of what they prefer as they do in what they are able to tolerate. This is especially true when it comes to media and root health. Almost all commonly grown houseplants and a fair % of succulents/cacti will do perfectly well in a medium that supports little to no perched water. For the most part, as water retention increases, the potential (growth/vitality) for an increasingly large fraction of plants decreases.

    So to answer your question, "Which plant, which mix?": With care given to appropriate watering and nutritional supplementation, the gritty mix can provide greater opportunity for most plants to realize a larger measure of their genetic potential. It's more forgiving of grower error, as long as you're fertilizing and watering appropriately. The downside is, it's heavier, costs more to make, and it takes more effort to make (because it needs to be screened) than say the 5:1:1 mix. I currently use it almost exclusively because bonsai is stressful (for plants), and my woody material recovers much faster in more open (higher air porosity and no perched water) soils. Plants with a high level of genetic vigor are good candidates for soils like the 5:1:1 mix. I figure if a plant is so vigorous I can count on it needing an annual repot, I'll use the 5:1:1 mix. If it will be 2 years or more in the same medium/pot, I almost always opt for the gritty mix. That's just me - YMMV. While there is no right or wrong associated with your choices, your choices can have a great deal influence on the results you can expect/achieve.


    Jim Gerstorff thanked tapla
  • Jim Gerstorff

    Thank you Al. That definitely answers my question.

    And you may be correct Dave, it might be that I had the 2 mixes confused as the water retaining is concerned. And thank you also garden for pointing that out.

    I've had my share of root rot problems as of late & I don't want any more.


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