I was always told good drainage was key to a good soil mix, but the 3LB article say that they use no drainage with better results. Anyone else not drain? My gut says drain.

[minds_I]

Hello,

Yeah, Soma uses no drainage either.

On the other hand, I have drainage, but after I water/fed, the runoff wicks back up into the soil overnight (sometimes within hours). I lose little to evaporation so it is simillar.

minds_I

[3BM]

Hey Grey:

Drainage serves to allow water to pass through soil, leaving behind pockets of air. Roots need both water and air to thrive. A soil of proper texture will always contain some air, even when heavily saturated. Drainage in this context (container gardening) means having holes in the bottom of your pots. These holes allow excess water to escape the medium preventing oversaturation. By extension, if a container recieves no excess water, none will escape through the holes provided. 3LB simply didnt overwater. No excess water, no holes needed. Without holes, water simply collects at the bottom of the container and is transported via wick effect all throughout the soil. Drier parts of the dirt will draw water from more moist areas, and so proper watering will provide enough but not too much. Until you develope a sense of how to water your plants, your containers, and your soil it can help to do some testing. Moisture meters are available to test soil moisture content, or you can just put a few plants in pots with covered holes (say by several layers of news paper). Water as normal then see how the plants react. Test saturation by lifting the container and feeling its weight; over saturated soils are VERY heavy. You should figure out quickly how much is too much. Next, dont water until the plant leaves wilt slightly. Lift the pot now and make this the "dry" standard. Now simply keep the soil between the extremes of saturation and dryness through alternating periods of wet/dry. Find the balance through experimentation and you will have success with or without drain holes.

A final note on drain holes: they can be used to "flush" a plant after over feeding. This flush is a form of stress where the down falls of oversaturation are outweighed by the necessity of relieving a toxic nutrient condition in the soil. If you are inexperienced with your feeding regimine, having holes can help remedy serious errors. However, the stress of the flush is such that none but the most severe cases of toxity warrant it. So, dont overfeed and you wont need to flush. No need to flush, no need for holes. 3LB also did not over feed. Less is more, and listen to the plants. Once again you can have success with or without holes, but with experience they become less and less a necessity.

Hope that helps some. Good luck getting started on turning that Greythumb, Green!

3BM

Originally Posted by minds_I

Hello,

Yeah, Soma uses no drainage either.


minds_I

Soma's bed method does use drainage, that;s the whole point of the bottom layer of baked clay pellets or "hydrocorals". He use PVC pipes in the corners that go down to the clay pebbles for oxygen to the roots. But it's not just a rubbermaid full of soil or something. The excess water will drain off and evaporate through the pvc pipes.

[Suby]

I think drainage is key, there is no real advantage to having a no drain setup.
You might need to flush your plants, you might misjudge the amount of water and leave the plants with "wet feet" which can lead to root rot.
Plus the added holes in the pot at the base allow for oxygen to the bottom of the root system.



Plus under pot containers are like .50$ to collect runoff.

Suby

I have had many a run without drain holes with excellent success. As an earlier poster said...the key is not to overwater. I have since started to use drain holes just because I feel it's better to be safe than sorry...and I may try a rtw system in the future, and I want my containers to be ready.

Cheers,
SH

[ChaoticEntity]

I use no drainage in my organic soil mix, just don't overwater or put anything in the soil that can build up to toxicity(ie hard water building up Ca to toxicity)

[3BM]

Watering without drain holes keeps liquid from leaking out onto the floor, without needing any catch tray. No catch tray is nice since I move my pots every day. The water which collects at the base of the pot is transported throughout the soil via capellary action, so no "wet feet". My soil mix also contains enough perlite to ensure that roots always have access to oxygen. Allowing the soil to completely dry between waterings is another way to ensure that roots have enough air to thrive. The problems many growers attribute to "lack of drainage" have more to do with soil texture and watering habits, then not having drainage holes.

Success in a grow will never come down to holes or no holes. Rather, choose one or the other and exploit the advantages fully. Overwatering and overfertilizing will hurt your plants whether you have drainage holes or not.

3_B_M

[Suby]

A simple solution to this is just to put a few inches of clay pebbles or hydroton to the bottom of your containers, this ensures an air pocket at the bottom of the plant.

3BM

I never let my organic soil dry out between waterings, this is a good practice in inorganic soil but I fail to see the point in organics, the microherd is very sensitive to drying out and our most precious ressource here is the herd.
I think drying out is overstated, you quite right is saying that it's all about the right sol texture and with 30% perlite overwatering is not really a problem.

.02$

when i gre chemi still, i always watered so that there would be about 10% runoff to carry some of the excess salts out. 1 out of 3 waterings would be just water, no ferts, and i would allow lots of excess water to drain out. then i had to sponge this water from the floor, what a pita!

ive been growing organic for a year and a half now. i water with tea just enough so that some comes out the drain holes, but not to the point of oversaturation. i feed the tea twice, then the third is just water. my pots are on tables now and i just shopvac the excess water or tea and pour it on the veggie garden