MM Dehydrating Too Fast

I need some help here.  My beds are drying out too fast.  Is this a result of:

1) intensely  planting
2) old mels mix
3) not enough mulch or the right type of mulch
4) or just mels mix does not hold the water.

The beds that are drying out vary in size and are planted intensely with various varieties of beans. Three of my beds are 3 feet by 8 feet by 10 inches high.  They were built in 2012.  I add at least 15 gallons of compost every time I plant.  I fill the beds to the top and let them sit at least a week before sowing seeds.  Then I wait a couple weeks until the plants are high enough and then add the mulch.  So they get at least two inches of mulch depending on how much settling has occurred.  All three beds have 8 squares of pole beans on a trellis and then 16 squares of bush beans planted on the other side of the bed.  In two beds I used leaf mulch and in one bed I used wheat straw.  I have a soaker hose under the mulch.  The beds are open to the ground under the beds with red georgia clay under the Mels Mix.  In the morning, if I run the soaker hose for 1 hour, the water will be seeping out under the beds.  After only 24 hours, the beds will be bone dry.  I used a moisture meter and was flabbergasted to see that they measured dry.  I thought something was wrong with my meter so I stuck my finger down in the MM and sure enough it was dry as a bone. 

So my question is, why is it drying out so fast.  The previous two years, I grew Rattlesnake beans in a 2 x 8 bed that was built in 2014 and I had the same drying problem.  This year I am growing sweet potatoes in that bed and only need to water about every three days.  I know I live in a hot climate but having to water every day for 1 hour for some of the beds is driving the water bill sky high.  Last month the water bill was over $200.  Not all of that is being used on the veggie garden.  We do have a sprinkler system for the lawn also.

I grew corn in a 4 x 8 bed that was built with 4"x 4" boards stacked two high with Modified Mels Mix.  About 1/2 of the growing medium is regular top soil and 1/2 is MM.  The soil is covered by wheat straw and corn is planted 1 stalk per square.  I only have to water once a week in this bed.  So is the difference the intensely planted beans vs the not so intensely planted corn.  Or is the difference the soil.  Or is the difference the thickness of the bed walls.  The bean beds are made from 2 in thick pine and the corn bed is 4"x 4" boards stacked two high.

Because the wood sides of the beds are decaying and I now have Southern Blight infected soil, I will be replacing the beds and growing medium this fall and winter and I need to do something to help keep the beds hydrated.  I am going to set up drip irrigation in the new beds but that won't help them from drying out so fast.  And yes, before I plant, I water the bed thoroughly and stir the MM up and water again and keep doing this until all the MM is completely hydrated.

I would say the first three on your list. Also not adding enough compost before planting. Perhaps too !anyone too big drain holes. Not watering enough.

Use finished, but not aged  compost for mulch.

Can you harvest rain water. Do you have a cistern?

Is this the first year using the soaker hose?

I suspect the problem is actually the reliance on the soaker hose. Remember, how Mel used to tell us, don't worry, you can't over water Mel's Mix.  He's right. It drains super well.

When a soaker hose is used, the Mel's mix acts like a very loose, very sandy soil.  The water from the soaker hose goes straight in, and straight down.  In your case, straight down to the Georgia clay and then seeping out under the edges of the raised beds.

I've had huge problems using drip irrigation in my beds.  Always thinking I've got the watering wrong.  The real issue as I've studied up, it's my watering, it's the Mel's mix ability to horizontal transport the water.  It doesn't. 

I suspect if you run a little experiment and check your soil, it'll be dry, turn on the soaker hose, wait until the water seeps out and check again, a few inches from the hose it'll still be bone dry.

$200 for water! Of course, Yardslave at $500 a month probably gets the blue ribbon.

I think one problem with drip lines is that the water eventually creates vertical channels (channeling). I get quite a bit running out the bottom. Maybe moving them left then right would help. Using the hose wand seems to keep my beds more uniformly moist and sometimes, nothing or very little drips out the bottom. I have chopped straw as mulch. I know nothing about soaker hoses.

camprn wrote:I would say the first three on your list. Also not adding enough compost before planting. Perhaps too !anyone too big drain holes. Not watering enough.

Use finished, but not aged  compost for mulch.

Can you harvest rain water. Do you have a cistern?

Thanks for your response Camprn. 

I add compost until the bed is completely full.  I then mix the compost with the MM already in the bed.  It is full.  I saw in another of your posts that you remove some of the MM and add a lot more compost.  Do you think that may be the answer.  I have been wondering if the growing medium is the main problem.

I can try using finished but not aged compost as mulch but I don't see that that would be any better than the partially composted leaves.  In two of the beds, I used one year old decaying leaves as mulch.

I do not have any drain holes.  The bed sits directly on the soil below the bed.  The soil is clay and therefore the water does not seep into the soil under the bed.  Except, last year when I emptied the beds and cleaned out the roots in three of the beds, I did lay cardboard down.  I watered the cardboard and punched holes in the cardboard where the water pooled.  So the cardboard could be one of the problems.  When I redo the beds this year the beds will be raised above the ground about 12 inches so it will be just as bad because the water will just drain down.  

I do not have a cistern.  I could try eventually to set up a rain collection system.  Right now all my down spouts go into pipes in the ground which lead away from the foundation of the house.  But the real problem lies in having to water so often.

No_Such_Reality wrote:Is this the first year using the soaker hose?

I suspect the problem is actually the reliance on the soaker hose. Remember, how Mel used to tell us, don't worry, you can't over water Mel's Mix.  He's right. It drains super well.

When a soaker hose is used, the Mel's mix acts like a very loose, very sandy soil.  The water from the soaker hose goes straight in, and straight down.  In your case, straight down to the Georgia clay and then seeping out under the edges of the raised beds.

I've had huge problems using drip irrigation in my beds.  Always thinking I've got the watering wrong.  The real issue as I've studied up, it's my watering, it's the Mel's mix ability to horizontal transport the water.  It doesn't. 

I suspect if you run a little experiment and check your soil, it'll be dry, turn on the soaker hose, wait until the water seeps out and check again, a few inches from the hose it'll still be bone dry.

This is the first year using a soaker hose in the three beds I am having the most problem with.

I am pretty sure I have checked the moisture of the MM a few inches away from the soaker hose but I will try again tomorrow.  Thanks for your help.

sanderson wrote:$200 for water!  Of course, Yardslave at $500 a month probably gets the blue ribbon.

I think one problem with drip lines is that the water eventually creates vertical channels (channeling).  I get quite a bit running out the bottom.  Maybe moving them left then right would help.  Using the hose wand seems to keep my beds more uniformly moist and sometimes, nothing or very little drips out the bottom.  I have chopped straw as mulch.  I know nothing about soaker hoses.

Thanks for your suggestions Sanderson.

I did use a hose wand the previous four years.  It takes forever to get the water thru the mulch and into the MM.  Last year with the 2' x 8' bed planted with Rattlesnake Beans I would take a small stool and sit beside the bed and water and water and water.  I decided I didn't have the time to continue doing that.  I had planned on setting up drip irritation this year but being called out of retirement blew that idea.  Therefore I tried soaker hoses this year.  The principle of the soaker hoses is basically the same as the 1/4 drip type tube you are using in your beds.  The water just seeps out all along the hose rather than just where there are holes like in your drip hose.  But I am not sure the drip irrigation will do much better.

Yolos you can still do 'drip' irrigation, you just need too use a different kind of drip head.
 
The best I've seen is using the umbrella bubbler drip emitters.  You don't want the stream bubbler, the streams are better than point drippers but still pretty focused and when dialed down to hit a single square give dry spots.

The micro-shrub bubbler with umbrella pattern does a better job of watering the whole surface area which then reduces dry vertical channels.  

CitizenKate has the bubblers set up in this thread so you can see what the watering looks like.  https://squarefoot.forumotion.com/t19889-new-drip-irrigation-contraption?highlight=bubbler+drip+irrigation

My Mels Mix dries out quickly as well.  I think with our freeze/thaw cycle my coarse vermiculite breaks down over time and loses water-holding capacity. 

Some nutrients bind in the soil while others are leached away since it drains so freely.

Once the mix dries out it is not that easy to re-hydrate.  I flood squares and come back to check and it's only wet an inch or so down...I need to get better at longer watering sessions to discourage shallow root systems.  Good soaking rains are always welcome.

As an experiment, I am thinking of adding native loam soil to a couple of my SFG boxes to see how they do this fall and next year...a little bit better soil and nutrition retention...may have to battle some weed seeds.

I'm following this thread closely because this year, even though I water the usual amount of time with a wand or watering can, when I scratch below the surface it's completely dry. Only about 1/2 inch is moist. I can't figure out where all that water is going since it's not pooling or running off.

I've taken to planting in a 'bowl' of almost straight compost just to be able to water the poor things. I've also been researching drip lines but so glad I read the above so I don't waste my time.

CC

I wouldn't be too hesitant about installing drip irrigation. It is great for when you have to go on vacation, are away from home more than a day, or get sick, hurt, etc.. The plants may not be thriving when you get back but they will be alive for you to revive. Even vertical plugs of wet MM will be better than nothing.

Mel designed a method for gardening that does work, but in the summer with water rationing or being expensive, it can still be a challenge to keep the MM moist. I think, and this is just my personal thought, is that the burden is on us to keep the MM moist from the get go, to never let it dry out when there are plants in the boxes. The worms and microorganisms also need moisture. It is hard to re-hydrate once it is dry unless you can water, turn, water, turn, etc. like we do when making the Mix.

Keeping it moist and re-hydrating are where I think a good mulch really shine.  Wood chips, straw, anything that absorbs the water and then re-releases it to the soil.  

As Sanderson mentioned, the drip irrigation still works and a little supplemental soaking helps.  

I've been finding flooding to be my best option, flood the bed, let it soak the chip/bark mulch and soak in, the  do it again.  

I use one of these. 


Allows me to turn the hose on full blast to quickly flood the bed without ripping up the mix or plants.  Even then, the water soaks in so fast.

A few years ago we had a thunderstorm drop a few inches of rain over my SGF boxes over a few hours...and later that evening I dug into a few of my 12" deep boxes and the lower 6" were completely dry.  I think the mix is like a sponge...and when it dries out it takes a lot of water to rehydrate.  I just pulled up a few of my struggling cucumber plants and found the entire root system only went down a couple inches...probably as far as the water soaked in.

I just cleared a few 4x4 boxes of old green bean and under-productive pepper plants to get ready for some fall seeding...I have cucumbers along a trellis in those boxes.  I removed about half my cuke vines...and when I tore the vines out of the Mels Mix each vine root went across the entire box only about 1" deep.  No wonder when I soak the squares at 6:30 in the morning the mix is hot and dry in the extremely hot summer we've had to date.

landarch wrote:I just cleared a few 4x4 boxes of old green bean and under-productive pepper plants to get ready for some fall seeding...I have cucumbers along a trellis in those boxes.  I removed about half my cuke vines...and when I tore the vines out of the Mels Mix each vine root went across the entire box only about 1" deep.  No wonder when I soak the squares at 6:30 in the morning the mix is hot and dry in the extremely hot summer we've had to date.

Huh!  My 3 cuke vines are suffering big time.  Probably the same plight.  We have had zero rain basically in 2 months.  All hose, and that is when I can devote a couple hours to it.....

Is it possible since your beds are open below, there is something sucking the moisture away ?  My 5 beds have used the same mix for 4 years. In this past heat wave and dry weather I only water my plants every other day, maybe slip in a day . I use about 1 quart for each square, a 1-1/2 gallon bucket does 6 squares for me. My mix below isnt wet, nor is it dry. I have maybe 1-1/2 inch of wood chips and shredded newspaper for mulch.
I have spaces of 16 inches between my beds and ground with good drainage holes in bed flooring.
My beds do not receive sun till around 1pm.,that could be a factor in slow evaporation.

In this summer heat and humidity, it's a wonder anything is surviving!
I have a grape arbor, 12 ft. wide, 4 plants on each side, in the ground, soil clay and sand, absolutely horrible, but the grapes love it. We put a soaker hose, down 1 side, across and down other side. We had the same problem with reg. dirt, it is piled higher than surrounding soil. We did all sorts of stuff that did not work. We finally put cardboard under the hose. This slows down the drips and spreads it out over a larger area. The water still gets thru, but the cardboard helps. If you have a plant in the way, just wet the cardboard and tear to go around plant. Then put the mulch back on top.

Now to a couple things I've done that breaks most folks gardening rules:
First off, I live in the deep South. In July, we had 29 days of above 90 degrees, and most of that time the humidity from 75 to 99%.
Maybe once per month, in very hot weather, and the MM will not accept water, like it has oil on/in it, bone dry. I take a spray bottle, a couple tea. dish soap (I use dawn, since it is safe for animals) fill with water. I spray the mm or spray into the water that I put on soil. I don't spray much, but this let's the MM get wet again. Don't spray plants,since this could burn leaves, at least rinse it off the leaves.
2nd. I water the plants from above. I only spray fully grown plants. They seem to like the cooling water spray.
3rd I only do this if we have not had any rain, and morning watering does not seem to be helping the plants. I water in the evening. In this heat, the plants will dry but they get a good drink for several hrs. I don't do this if any blight is in the garden.

Jo

Thank you all.  Your suggestions have been helpful.  When I replace my beds and soil this fall/winter, I may do a lot of experimenting.  I will be adding 7 beds that will be 2 feet by 6 feet and renovating 3 beds that will be 3 feet x 8 feet (maybe). So that gives me plenty of beds to experiment.  I will definitely do drip irrigation of some kind.  I will have to raise them all up off the ground because of the oak tree on one side of the garden and two dogwood trees on the other side.