Topic: Why do we water from the bottom?

[laurieuk]

We all do things in different ways for different reasons and I am often wondering why some people water plants from the bottom. I try to follow nature if I have a problem and anything we grow in a pot, somewhere in the world the same plant grows outside. Apart from water lilies I cannot think where the rain does not come  down to water from the top. I do not water anything from the bottom and when I did try my begonias on capillary matting I found all the bottom roots rotted. I always say if you do it from the bottom and have success continue but cannot understand why.
I know many books etc. say do this but why ?
I bet I get some flak now!!!!!!

[djbrenton]

Some plants grow naturally in conditions where the drainage is so good/the rainfall is so low that the topmost inches of soil have virtually no water. Such plants can rot if the higher roots/stem are too wet. Cacti are an obvious example.

[Amazin]

Seedlings and small pots I water fom the bottom. It avoids the weight of water splashing delicate seedlings to squish, and I reckon it stimulates the roots.

[kt.]

Watering most plants from the bottom causes the root system to search for its water supply therefore enhancing growth. Though I will water also from the top if the plant appears to be wilting too much...

[star]

The reason your begonias rotted on the capillary matting is because they were sitting in the wet. When I water from the bottom, I leave the pot in water, about an inch or so, only for a few minutes. Then take it out and let the excess water drain off. I let the plant dry out completely before it gets watered again.

As djb said most houseplants are tropical and dont get much natural rainfall, they grow on free draining soil or sand and most do better in drier conditions. The main part to rot is the stem where it joins the compost, its only my thoughts but possibly its because the roots take up the moisture, were the stem doesn't.

The temperature also has a lot to do with it, our homes are a far cry from the heat these plants grow in naturally, so the wet compost around the stem takes too long to drain away which in turn encourages rotting.

I hope that makes sense. It is a bit long winded sorry.

[Robert_Brenchley]

I used to water cacti copiously in the growing season, and they were perfectly happy as long as they were growing actively, and had plenty of light and air. If plants are rotting, I'd tend to look for other explantations first.

[Busby]

I think the main reason why your begonias rotted on the capillary matting is simply, and notwithstanding your efforts,  because that's not their natural environment.

We make a lot of mistakes, have a lot of disappointments (like trying to grow tomatoes outside in our climate) because we forget that basically plants in nature 'choose' where they want to grow.

In the biological-dynamical science of agriculture, weeds are an indication of what the earth needs, so that when the weeds die off the soil's missing elements, inherent in the dead weeds will be returned to the earth.

Whether water gets to the roots from above or below isn't the deciding factor - for instance palm trees have a special capillary system allowing water to be taken from below. So they wouldn't benefit from rainfall until the rain has soaked into the ground.

The last time I was in Tenerife I walked along a pavement where fruiting tomato plants were growing out of the cracks in the pavement!

So stick as near as you can to nature.

By the way, I've had a lot of success with various seedlings and seeds by putting them direct into earth specifically sold for geraniums: cucmbers, zuchetti, tomatoes, peas and lettuce.