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briana_2006

Growing advice for Fig Trees

briana_2006
11 years ago

Hello all -

Sorry for the long post that contains many questions throughout the body of the text.

I am just trying to think of all my questions so hopefully I can have a really good yield of figs this year.

I would like to ask for some advice for the 2013 growing season for fig trees.

I am going to post this message in both the container gardening forum and the fig forum.

The trees range in size from ~ 2 feet to over 5 feet and are as old as 8 years (5 foot trees) to as young as ~ 5 years old.

Most of the yields in the past few years have been fairly small considering the number of trees I have in pots.

Some of the low yields were deserved because of a bit of lack of time to fertilize as much as I would have liked. However, I should have more time this year.

The containers I have been using for my fig trees are on the order of 10 gallons.

I have purchased new containers for this year due to the previous plastic pots degrading in the sun.

The previous pots were a gray stone color. The new pots are black plastic.

I have two pot sizes available for use: 15 gallon pots or 25 gallon pots.

Let me know if I should post some pictures of the current pots, new pots, or the trees.

Question:

Assuming a mix that allows for optimal root health does anyone have a prediction for how much increase in terms of overall health, appearance, fruit production, and growth of a fig tree I may expect to see when a tree is grown in a 15 gallon pot versus a 10 gallon pot (1.5x increase in volume of container) or a 25 gallon pot versus a 10 gallon pot (2.5x increase in volume of container) within 1 season?

I have used the gritty mix with very good results for various plants grown in the house in much smaller containers than 15 or 25 gallon pots. The container sizes are such that I have used about 3-4 quarts of the final prepared mix.

I am curious to know if the expectation of growth/fruit production/overall health for fig trees would be essentially the same for both the gritty mix and a freshly made batch of 5-1-1 where presumably there is little to no decomposition of the peat. Or would one mix over the other be considered superior for maximum growth/fruit production/overall health in a season?

I know between the gritty and 5-1-1 one difference is I can go much longer between repots assuming roots do not need to be pruned - up to 5 yrs for the gritty mix whereas the 5-1-1 should be replaced after 1 season due to decomposition of the peat component.

I am concerned about the weight issue of the gritty mix especially at container sizes of 15 to 25 gallons, which will be extremely heavy. The weight of the 5-1-1 would of course be considerably lighter. However, if I could expect much better growth in the gritty mix then I should go with that mix and try to get a dolly or something to move the containers from my garage to the side of the driveway.

I could try putting the pots on a plant dolly that has wheels that lock My driveway has a slight gentle slope that leads to the street. Is my assumption that with locked wheels on the plant dolly the pots will be heavy enough with the gritty mix to not roll down the driveway into the street with any strong winds? Would this be the case with each container size: 10, 15, and 25 gallons? I have to have something so that I can move the pots weekly a foot or so towards the inside of the driveway so that the tree branches will be out of the way when I cut grass.

The containers will be located outside, in the Saint Louis area, in full sun all day in summertime temperatures that may be anywhere between 80 to 100 degrees.

Since I assume some have switched from growing fig trees in peat based soils to either the 5-1-1 or the gritty mix, I would be interested in hearing about your experience. If pictures are available of the tree growing in the gritty or 5-1-1 mix compared to peat based soils please post.

I last did root pruning in spring 2011 and so I am planning to again root prune this year. I have noticed that for the last few years my trees tend to break dormancy around the end of February.

Unfortunately, this means I should root prune (I think) toward mid February. However, mid February is still too cold outside to work comfortably for extended periods of time � especially if I will be washing off peat based soil from roots to transfer into the gritty mix.

In order to rinse any remaining peat based soil off of roots how long may I keep the roots in a bucket of water (instead of spraying with a hose as I did the last time I root pruned) without risk of killing the roots. I figure in this way I can gently raise and lower the roots in the bucket to release the last bits of soil after I remove the tree from the container or if I need to I can use my hand within the bucket of water to quickly remove the soil. I could set this up inside the garage to shield against cool/cold weather.

Question:

Should I cover the new black plastic pots with a reflective or white material (fabric) so as not to build up too much heat in the root zone due to the black color of the containers?

Also, would covering the containers with, for example, a white fabric be effective to help protect the containers from sun damage since the fabric should help to scatter the UV sun rays?

Question:

If I make the gritty mix using a 50lb bag of turface that has been screened (through insect screen) and 3 cubic feet of screened (through insect screen) fir bark (1/8 inch to
1 /4 inch from oakhill gardens) and a 50 lb bag of gran-I-grit grower size screened through insect screen, approximately how many of the 15 gallon and how many of the 25 gallon containers could I fill with the appropriate volume of soil? I have some calculations below.

If I remember correctly, Al Tapla indicated the above combined mixture should result in 7 cubic feet of total mix. Assuming I have remembered correctly then I calculate an equivalent amount of gallons of mix as 52.4 gallons:

7 ft^3 * (12 inches)^3 / (1 ft)^3 * (2.54 cm)^3 / (1 inch)^3 * 1 milliliter / 1 cm^3 * 1 gallon / 3.78 liters = 52.43 ~ 52.4 gallons.

Where: 7 ft^3 -- is 7 cubic feet - the ^ symbol indicates raising the previous number to the third power

Therefore, for a 10 gallon, 15 gallon, and 25 gallon container:

52.4 gallons * 1 pot / 10 gallons = 5.24 = 5 pots per gritty mixture as made above.
52.4 gallons * 1 pot / 15 gallons = 3.49 = 3.5 pots per gritty mixture as made above.
52.4 gallons * 1 pot / 25 gallons = 2.09 = 2 pots per gritty mixture as made above.

To try to get an idea of the cost comparison of the gritty mix compared to miracle grow peat based mix, I have calculated the following.

Price per pot of gritty mix (includes shipping price of fir bark to my location � I wish I could get a local store to bring some bark in for sale!):

~ $8 for a 50 lb bag of turface, ~ $8 for a 50 lb bag of Gran-I-Grit grower size, and ~ $35 for a 3 cubic feet bag of fir bark in the size range of 1/8 inch to 1/4 inch (including shipping and handling) = $51.

Price per gallon of gritty mix: $51/52.4 gallons = $0.97 / gallon.

For comparison: 64 quarts * 1 gallon / 4 quarts = 16 gallons of peat based miracle grow soil locally purchased for ~ $12.

Price per gallon of miracle grow peat based soil: $12/16 gallons = $0.75 / gallon.

The table below indicates the price equivalent of using the prepared gritty mix as described above compared to the price equivalent of using locally purchased miracle grow. As shown in the table, there is not a substantial difference in price to obtain a superior mix like the gritty mix.

Example calculation for:

$ Equivalent of Gritty Mix Used per Pot (10 gallon pot): 10 gallon/52.4 gallons * $51 = $9.73

$ Equivalent of Miracle Grow Peat Based Mix (10 gallon pot): 10 gallon/16 gallons * $12 = $7.50

10 gallon $9.73 $7.50 $2.23 (10/52.4)* 100 = 19.08%
15 gallon $14.59 $11.25 $3.34 (15/52.4)* 100 = 28.62%
25 gallon $24.33 $18.75 $5.58 (25/52.4)* 100 = 47.70%

The second column above represents the price equivalent of using the indicated percentage of the total prepared gritty mix for the 10, 15, and 25 gallon containers.

The third column above represents the price equivalent of using the peat based mix for the 10, 15, and 25 gallon containers.

The fourth column above represents the diffeence in price between using the gritty mix and the peat based mix for the 10, 15, and 25 gallon containers.

Therefore, row 1 suggests the 10 gallon container uses ~ 19% of the total prepared gritty mix and represents $9.73 of the total $51 for all of the prepared gritty mix compared to $7.50 for using 10 gallons of the peat based mix. The difference in price for the mixes for the 10 gallon pot is $2.23.

Question:

After transferring into either the gritty mix or the 5-1-1 mix after root pruning do I need to tie down the trees in some fashion to the containers to keep the trees from blowing over in the wind? If so, could I remove the ties in 2 weeks, 1 month?

Question:

I am using Foilage Pro 9-3-6 and ProTekT 0-0-3 as fertilizer.

What would be the best fertilizing schedule for the trees assuming the gritty mix or the 5-1-1? -- Half dose 1 time per week with just giving water as needed the remaining times to compensate for water used by the plant/lost due to heat evaporation?

Last year in peat based soil I fertilized full strength with the same fertilizers every 3-4 days and tried to flush with water every couple of weeks. I managed to get a lot of fruit set but a lot of fruits also dropped I think because of the hot weather � we had a couple of weeks of 105 degree weather � I think I should have given them water both in the morning and at night � instead of just at night.

I add 1.25 teaspoon of 5% white vinegar to 1 gallon of water to make my fertilizer solution slightly acidic.

Do fig trees need slightly basic fertilizer solution as it seems I have seen in some posts � Should I not acidify the water?

The first year or so I put a small amount of garden lime on top of peat based soil at the beginning of spring as I read about in some posts. However, I have not added lime in recent years.

Question:

I have a question concerning old fig branches and decreased fruit production.

I know the breba figs come on wood from the previous year and the main crop on new wood.

I have had some of my trees since 2005 and have never cut a branch off or pruned a branch. Will removing a branch or branches produce stronger new growth and better/more figs?

Should I remove branches or parts of branches?

So, after all that I have discussed, please give me advice on the things I should change: container size, mix, pruning, pH, fertilizer frequency/strength etc. so I can get the best possible growth/fruit production this year.

Sorry for the long post. But I am really trying to get good fruit production this year.

Thanks,
Brian

Comments (5)

  • Ohiofem 6a/5b Southwest Ohio
    11 years ago
    last modified: 9 years ago

    Way too many questions to answer in one post. I'll just say that your calculations are wrong. 50 lbs of gran-I-grit is less than 1 cubic foot and 50 lbs of turface is about 1.5 cubic foot, so you would need about 150 lbs of grit and 100 pounds of turface to be equal to three cubic feet of bark for the gritty mix. if you had 3cf of each ingredient you'd have a total of about 67 gallons of mix for about $71. (Your bark is the most expensive ingredient, which is very unusual. $35 for 3 cf of bark is way more than I've ever heard of. I pay less than $2 a cubic foot.)

    The question about gritty vs 5-1-1 was addressed in the other thread started by Nakaii that you participated in. Al thinks gritty will produce superior results. Josh thinks 5-1-1 works very well for vigorous growers like figs and 5-1-1 will hold up well for a couple years. They're both expert growers and you wouldn't go wrong by following either ones advice. It's up to you.

    This post was edited by Ohiofem on Mon, Feb 4, 13 at 19:51

  • greenman28 NorCal 7b/8a
    11 years ago
    last modified: 9 years ago

    Overall, I think gritty mix is the superior mix.
    In the other Thread, I recommended the 5-1-1 because the grower, Naikii, wasn't going to bare-root his plants,
    which is less of a problem when transitioning to the 5-1-1. That choice was solely based on his situation.

    For my own fig, I grow in 5-1-1 for convenience - ease of mixing, economy, and weight. When the tree is larger,
    and ready for a large container, I'll switch it over to a gritty mix and not re-pot as often.


    Josh

  • MadameMeow
    11 years ago
    last modified: 9 years ago

    this might not help much, but regards the black plastic pots- I shade the pots by clustering smaller pots (1-gallon) of annuals or herbs around them. It seems to work fine, and my stone patio's SE exposure has left me with melted plastic cookie containers (the clear plastic survives the dishwasher, but not my patio!).

  • meyermike_1micha
    11 years ago
    last modified: 9 years ago

    WEll:

    I too am a Northern Fig Grower with over 15 of them at the moment resting in my shed, dormant!
    They grow like weeds if grown in the 5.1.1 mix and I have to change them out of their pots into larger ones or trim them back and stick them into the same pots every spring before they awaken.

    I use the 5.1.1 for the same reasons Josh does:-0)

    Mike

  • briana_2006
    Original Author
    11 years ago
    last modified: 9 years ago

    Hello All :

    I apologize for another long post.

    I will divide this post into a response to answers received from the previous post followed by several additional questions followed by a recalculation to correct the volume/cost of the gritty mix and present some weight values for the 10, 15, and 25 gallon container sizes discussed previously when filled with dry/wet gritty mix. Here goes:

    Response to previous answers:

    Thanks to everyone for their comments to my previous post.

    Thank you Ohiofem for correctly pointing out the previous calculation of dollar per gallon was incorrect because the stated volume of mix, 7 ft^3, prepared from a 50 lb bag of turface, a 50 lb bag of Gran-I-Grit, and a 3 cubic foot bag of fir bark was incorrect . My memory for the combined volume of 1 bag of each component was not correct.

    I also noticed in my previous post that while the result of 52.4 gallons resulting from the conversion of 7 cubic feet of actual mix was numerically correct I did inadvertently leave out a factor (1 liter/1000 ml) in the calculation shown in the previous post, which would not have given the stated result. Sorry for the confusion.

    As suggested by Ohiofem I would be able to make the gritty mix more cheaply if I could find a local source for the pine/fir bark. When I first started trying to put the gritty mix together I experimented with the Reptile bark (~0.93 cubic foot size bag) some are using to build the mix that I bought at a local pet store. However, it seemed that by the time I screened the material I was throwing large amounts out because the size was not correct. Therefore, since I have a number of trees I just bought the same type Al T uses but there is of course the issue of shipping and handling which increases the cost. So far I have not been able to get a local Lowes or other box store to bring in the bark so I can get it cheaper. I have also, unsuccessfully, tried to get local nurseries to bring in some of the bark with their regular orders. This is in part why I would like to get quantitative information about how well the gritty mix is expected to outperform the 5-1-1. I am assuming I can find the bark needed for the 5-1-1 locally and no screening is required. Therefore, if general plant performance in 5-1-1 is only slightly different than in the gritty mix then perhaps I should switch to the 5-1-1. However, if the gritty mix is far and away more superior and I will get such better growth then perhaps I need to find a way to deal with the gritty mix problems (weight, price, size of container to use, reduced number of plants to transfer into the mix, etc).

    The consensus seems to be that while the gritty mix is viewed as superior for figs and it seems plants in general, the 5-1-1 mix is being used more frequently for growing fig trees. The preference for the 5-1-1 mix seems to be primarily the lighter weight for the same volume of mix allowing easier movement for larger container volumes of potted trees, ease of finding the components for the 5-1-1, and cheaper cost of building the 5-1-1 mix (I have a lot of trees: the revised calculations below for gritty mix of ~ $100 for ~ 67 gallons of gritty mix would not be enough to pot all my fig trees let alone other plants I currently have).

    It has been noted in response to my previous post that figs grow like weeds in the 5-1-1 mix. Unfortunately, I have not had any replies from someone growing fig trees in the gritty mix. If I correctly read previous replies it seems one can get 2 growing years out of one batch of 5-1-1, which sounds good since I thought it must be made fresh every year.

    Doing a quick calculation for the 10, 15, and 25 gallon containers for the number of fig trees I have indicates that I would need to invest the following amounts at the current price of ~ $100 for ~ 67 gallons of gritty mix (see detailed calculations below) to prepare enough gritty mix to pot each fig tree into the container size specified below.

    10 gallon pot: $150.55
    15 gallon pot: $225.82
    25 gallon pot: $376.37

    The breakdown would be:

    10 gallon pot: 1.63 bags of bark + 3.46 bags of turface + 8.01 bags of Gran-I-Grit
    15 gallon pot: 2.44 bags of bark + 5.28 bags of turface + 12.24 bags of Gran-I-Grit
    25 gallon pot: 4.07 bags of bark + 8.80 bags of turface + 20.40 bags of Gran-I-Grit

    Conclusion : I need to find cheaper ingredients, use smaller containers, graft multiple varieties onto 1 tree to reduce the number of overall trees needing mix, drive to oakhill gardens to buy numerous bags of bark which if I remember the price correctly will cut the price of the bark in half: costs as much to ship it as it does to buy it, or find a cheaper mix that can work as near as effectively as the gritty mix as possible. This is another reason why I would like to get quantitative information about how well the gritty mix is expected to outperform the 5-1-1.

    Several Additional Questions:

    Question:

    Am I correct in remembering that the polymer containing moisture control peat based soils are also not good because of the ‘pudding argument’ advanced when discussing adding perlite to peat based soils to make the soils drain excess water better? Or does the polymer absorb enough water so as not to allow a significant perched water table? Even if the polymer inhibits the perched water table is compaction of the peat based material severely limiting to roots and thus growth of the plant?

    Question:

    I may have missed this in previous posts from Al T or others but approximately what volume of a 50 lb bag of turface should I expect to lose from the screening process? I have asked in previous posts but have not received an answer. I would like to estimate how much higher the cost of the mix will be when considering the loss of turface due to screening.

    Question:

    Is there a way I can get the same benefits of the gritty mix and decrease the weight of the mix? Could I incorporate horticultural grade perlite, available locally, into the mix? If so what ratio of bark:turface:granite:perlite should I use?

    Question:

    Can the effective life time of the 5-1-1 be extended if after the second year (or even after the first year) the mix is sifted through insect screen to remove small particles resulting from breakdown of the peat/bark? Once removed by the insect screen, could the peat/bark fraction simply be replenished with fresh material by estimation of how much of each has been removed, which would come from the knowledge of the total volume of each that initially went into the preparation of the mix? I am assuming the peat fraction is the part that will be primarily decomposing into small particles and need replacement? I am thinking this may be able to be done if fresh 5-1-1 mix is made so that a plant is transferred into the fresh mix allowing the old mix to dry so it can be broken up and sifted.

    Question: (I didn’t receive a reply from the last post)

    I last did root pruning in spring 2011 and so I am planning to again root prune this year. I have noticed that for the last few years my trees tend to break dormancy around the end of February.

    Unfortunately, this means I should root prune (I think) toward mid February. However, mid February is still too cold outside to work comfortably for extended periods of time especially if I will be washing off peat based soil from roots to transfer into the gritty mix.

    In order to rinse any remaining peat based soil off of roots how long may I keep the roots in a bucket of water (instead of spraying with a hose as I did the last time I root pruned) without risk of killing the roots. I figure in this way I can gently raise and lower the roots in the bucket to release the last bits of soil after I remove the tree from the container or if I need to I can use my hand within the bucket of water to quickly remove the soil. I could set this up inside the garage to shield against cool/cold weather.

    Gritty Mix Recalculations:

    Below are revised calculations for the gritty mix.

    The next section of this post is a listing of the density: mass per volume of each of the components of the gritty mix.

    The density information for the Gran-I-Grit and Fir Bark were obtained by calling the companies, The North Carolina Granite Corporation for Gran-I-Grit and Shasta Forest Products for Fir Bark. The density information for Turface was obtained from technical specifications obtained from the company website: Profile Products, LLC.

    Density values:

    Gran-I-Grit (dry): 2250 lbs per cubic yard,
    Turface (dry): 36 +/- 2 lbs per cubic foot, and
    Fir Bark (dry): 54 lbs per 3 cubic feet

    Conversion of the densities to pounds per gallon:

    Gran-I-Grit:

    2250 lbs/yd^3 * (1 yd)^3/(3 ft)^3 * (1 ft)^3/(12 inches)^3 * (1 inch)^3/(2.54 cm)^3 * (1 cm)^3/1 ml * 1000 ml/1 liter * 3.78 liter/1 gallon =

    (2250 x 1000 x 3.78) / (27 x 1728 x 16.387064) = 11.12412 lbs/gallon ~ 11.12 lbs/gallon

    Turface:

    36 lbs/ft^3 * (1 ft)^3/(12 inches)^3 * (1 inch)^3/(2.54 cm)^3 * (1 cm)^3/1 ml * 1000 ml/1 liter * 3.78 liter/1 gallon =

    (36 x 1000 x 3.78) / (1728 x 16.387064) = 4.8056198 lbs/gallon ~ 4.80 lbs/gallon

    Fir Bark:

    54 lbs/3 ft^3 * (1 ft)^3/(12 inches)^3 * (1 inch)^3/(2.54 cm)^3 * (1 cm)^3/1 ml * 1000 ml/1 liter * 3.78 liter/1 gallon =

    (54 x 1000 x 3.78) / (3 x 1728 x 16.387064) = 2.4028099 lbs/gallon ~ 2.40 lbs/gallon

    Calculation of the equivalent volume of Gran-I-Grit and Turface using the previously calculated densities:

    Gran-I-Grit: 50 lb bag

    Volume = 50 lbs / 11.12412 lbs/gallon = 4.4947376 gallons

    Converting gallons to cubic feet of Gran-I-Grit:

    4.4947376 gallons * 3.78 liters / 1 gallon * 1000 ml / 1 liter * 1 cm^3 / 1 ml * (1 inch)^3 / (2.54 cm)^3 * (1 ft)^3 / (12 inches)^3 =

    (4.4947376 x 3.78 x 1000) / (16.387064 x 1728) = 0.600 ft^3

    Turface: 50 lb bag

    Volume = 50 lbs / 4.8056198 lbs/gallon = 10.404485 gallons

    Converting gallons to cubic feet of Turface:

    10.404485 gallons * 3.78 liters / 1 gallon * 1000 ml / 1 liter * 1 cm^3 / 1 ml * (1 inch)^3 / (2.54 cm)^3 * (1 ft)^3 / (12 inches)^3 =

    10.404485 x 3.78 x 1000 / (16.387064 x 1728) = 1.3888889 ft^3 ~ 1.39 ft^3

    Bark: 3 cubic feet bag as purchased

    Converting cubic feet of bark to gallons of bark:

    3 ft^3 * (12 inches)^3 / (1 ft)^3 * (2.54 cm)^3 / (1 inch)^3 * 1 ml / 1cm^3 * 1 liter / 1000 ml * 1 gallon / 3.78 liters =

    (3 x 1728 x 16.387064) / (3.78 x 1000) = 22.473688 gallons ~ 22.47 gallons

    Summary:

    Turface 50 lbs 1.39 ft^3 10.40 gallons 4.80 lbs/gallon
    Gran-I-Grit 50 lbs 0.60 ft^3 4.49 gallons 11.12 lbs/gallon
    Bark 54 lbs 3 ft^3 22.47 gallons 2.40 lbs/gallon

    Therefore, to make the gritty mix using the entire 3 cubic foot bag of fir bark would require 5 bags of Gran-I-Grit and 2.158 bags of Turface and would result in:

    Gran-I-Grit: 5 x 0.60 ft^3 = 3 ft^3; 5 x 4.49 gallons ~ 22.45 gallons
    Turface: 2.158 x 1.39 ft^3 = 2.999 ft^3 ~ 3 ft^3; 2.158 x 10.40 gallons = 22.44 gallons
    Fir Bark: 3 ft^3; 22.47 gallons

    3 ft^3 + 3 ft^3 + 3 ft^3 = 9 ft^3 or ~22.47 x 3 = 67.41 gallons of mix.

    The next section calculates the cost of the gritty mix when combining 1 bag of fir bark, 5 bags of Gran-I-Grit, and 2.158 bags of Turface.

    Gran-I-Grit: 5 bags x $8/bag = $40
    Turface: 2.158 bags x $8/bag = $17.264 ~ $17.26
    Fir Bark: 1 bag x $35 (includes shipping and handling) = $35
    Total: $92.26

    Price per gallon of gritty mix:

    $92.26/67.41 gallons = $1.368/gallon ~ $1.37/gallon

    For comparison: 64 quarts * 1 gallon / 4 quarts = 16 gallons of peat based miracle grow soil locally purchased for ~ $12.

    Price per gallon of miracle grow peat based soil: $12/16 gallons = $0.75 / gallon.

    The table below calculates the weight of the gritty mix when dry for each of the container sizes discussed in the original question posted. The table also calculates the weight of the mix when wet assuming I remember correctly that the weight increases by ~ 25% when wet.

    10 Gallon Container: 3.33 gal Grit * 11.12 lbs/gal = 37.06 lbs + 3.33 gal turface * 4.80 lbs/gallon = 15.98 lbs + 3.33 gal fir bark * 2.40 lbs/gallon = 7.99 lbs = 61.03 total lbs dry.

    15 Gallon Container: 5 gal Grit * 11.12 lbs/gal = 55.60 lbs + 5 gal turface * 4.80 lbs/gallon = 24.00 lbs + 5 gal fir bark * 2.40 lbs/gallon = 12.00 lbs = 91.60 total lbs dry.

    25 Gallon Container: 8.33 gal Grit * 11.12 lbs/gal = 92.66 lbs + 8.33 gal turface * 4.80 lbs/gallon = 39.98 lbs + 8.33 gal fir bark * 2.40 lbs/gallon = 19.99 lbs = 152.63 total lbs dry.

    An increase of weight of 25% when wet gives:

    10 gallon: 61.03 + 0.25(61.03) = 76.28 lbs ~ 76 lbs
    15 gallon: 91.60 + 0.25(91.60) = 114.50 lbs ~ 115 lbs
    25 gallon: 152.63 + 0.25(152.63) = 190.78 lbs ~ 191 lbs

    The table below indicates the price equivalent of using the prepared gritty mix as described (~67.41 gallons) compared to the price equivalent of using locally purchased miracle grow.

    Example calculation for:

    $ Equivalent of Gritty Mix Used per Pot (10 gallon pot): 10 gallon/67.41 gallons * $92.26 = $13.69

    $ Equivalent of Miracle Grow (mir grow) Peat Based Mix (10 gallon pot): 10 gallon/16 gallons * $12 = $7.50

    The first column below is the container size, the second column is the gritty mix price, the third column is the miracle grow price, the fourth column is the difference in price between the gritty mix used and the miracle grow used, and the fifth column is the percentage of gritty mix used to fill each container.

    10 gallon: $13.69 $7.50 $6.19 (10/67.41)* 100 = 14.83%
    15 gallon: $20.53 $11.25 $9.28 (15/67.41)* 100 = 22.25%
    25 gallon: $34.21 $18.75 $15.46 (25/67.41)* 100 = 37.08%

    Therefore, for a 10 gallon, 15 gallon, and 25 gallon container:

    67.41 gallons * 1 pot / 10 gallons = 6.741 ~ 6.5 pots per gritty mixture as made above.
    67.41 gallons * 1 pot / 15 gallons = 4.494 ~ 4.5 pots per gritty mixture as made above.
    67.41 gallons * 1 pot / 25 gallons = 2.6964 ~ 2.5 pots per gritty mixture as made above.

    Thanks everyone for your help!
    Brian