If you have to water Miracle Grow mix 2 - 3 times a day, I'd guess that your pots are woefully undersized. Or...the mix has dry-pockets and the entire volume isn't actually absorbing moisture.

Even when it's 108F here with 15% humidity, I only have to water my 5-1-1 containers every other day. I use 3.5 gallon nursery containers, and I shade the black plastic pots to keep the roots cool, but that's my only compromise.

5-1-1 holds LOTS of moisture because it is 70% bark, which has the same approximate moisture retention as peat, if compared volume to volume (a container of pure bark versus a container of pure peat). The bark, however, may not wick moisture as well, and thus the peat is added as a binding agent that evens the moisture throughout the mix. The Perlite adds durability and structure.

What are you planning to grow, and how large a container?

Josh

The pots I'm talking about are large pots outdoors on concrete around my pool..decorative plants...14 inch hanging baskets and some smaller pots,say 12-14 inch with annual flowers.I have large tropical's(ficus,bird of paradise,palms) and citrus I need to repot this spring and heard how great 511 is but I was leery about the moisture retention but what you have said is exactly what I have heard.The water seems to run out of the bottom quickly on the plants I have potted in this mix this winter. I have many pots of all sizes with the smallest being 12 inch clay,largest being 2 1/2ft by 20 inches.Is this mix better for larger containers? I will also have tomatoes and peppers in large nursery pots.

You might have to adjust your watering habits a bit....slower and more thorough watering.

Could it be that your bark is on the large side? I assume you're screening the bark with a 1/2 inch screen?

I just re-potted a Citrus in 5-1-1 mix this morning.

Josh

The other possibility is thst the MG soil is so waterlogged thst the roots only occupy the top third of the pot. I had a buddy thst had thst problem with some tomatillos in 15g pots with *gasp* field soil and compost.

Except for the hanging baskets, you should not have to water your pots 2-3x a day.

Thanks for the replies...I will do some experiencing with all your help! I really like the idea of the 511 mix and it is cheaper than buying bagged mix. Maybe moving the plants off of the concrete will help some also,but I definitely had to water 2 times per day most days when temps were in the high 80's and 90's which is the norm here.Thanks again!!

Why did you think you needed to water?

Was it because you saw the plants wilting and assumed they needed water?

Or were you actively monitoring the amount of moisture in the lower layers of the containers?

Josh

These plants were wilting and the pots were light as a feather with the soil shriveling away from the inside of the pots.I am familiar with plants wilting from heat and sun but that was not the case with these. 20 minutes after I watered they were their perky little selves again.I bought a ponerosa lemon in early January from a nursery which seems to be potted in a medium much like 511 . It is in a full sun window now and it thriving (lots of new growth and buds all over ) but I water it every three days which I thought was excessive due to being in a cool house in winter,hence my original question.

Well that definitely sounds like the pots had a large area of hydrophobic peat in the center that wasn't soaking up water. I am pretty familar with heat here in Los Angeles with our 90-110F weather with 10% humidity. Even my fig trees in 15 gal pots in full sun on a southwest facing hillside with high winds doesn't need water twice a day when the entire medium is fully soaked in the morning.

NIl might be on to something. When MG gets really dry it becomes Very hydrophobic. water will bead off it like water off a ducks back. To re-hydrate you have to mix water back into the soil by hand, & you can't very well do that w/ a plant living in it.

If this is indeed the case you could re-pot (with different soil) or use a surfactant (wetting agent).

Rob

Yep, that was one of the things I mentioned in my first post to this Thread - "Or...the mix has dry-pockets and the entire volume isn't actually absorbing moisture." Very common when using peat-based mixes.

Josh

Yep, sorry Josh.

Rob

I think I will definitely try re potting in 511 mix and see what happens . Thanks for all the input!!