"Bruce W.1" wrote in message
.. .
Doug Kanter wrote:


Without a soil analysis, "rich and fertile" don't mean much. But, even if
the nutrient balance was perfect for a given plant, you'd still need to
continue adding to the soil over a period of time. This could mean adding
compost, or mulches which contribute nutrients as they decompose. The
soil is not a static environment.
===============================================

Fair enough. Then maybe a better question would be how long does it take
a plant to deplete the nutrients in the soil?

Take for instance some fast growing house plant, in a pot, and with new
potting soil. This plant gets plenty of sun. How long before it needs
fertilizer? Without specifics and details it's probably difficult to say.
But in general, how long before the soil needs fertilizer? Weeks, months,
years?

Thanks.

I'm not trying to give you a hard time, but it all depends!

1) Potting soil: Not always fortified with plant food. But, let's assume it
is for the moment.

2) Size of the pot relative to the type of plant and how long it's been in
that pot. Why? Because some plants will become root-bound faster than
others, and water will pass right through rather than be absorbed by the
soil. So, you now have a situation where nutrients are being washed right
out the bottom of the pot. With a freshly potted plant, the soil will be
depleted less quickly than the same plant that's become root-bound.

3) Depends on the type of plant, of course. To confuse the issue further, a
house plant that flowers only at certain times of year may need to be fed
every few weeks during that season, and less often or not at all when it's
just making leaves. Others may only need food once or twice a year.

I don't always have the time to adjust to the various plants in the house,
so I compromise. I use Miracle Gro liquid, diluted 1/4 of what they
recommend (4 times more water, in other words), and use it with almost every
watering. Works for most of the plants, with the occasional exception, like
the cyclamen I abused horribly over the past couple of months.

If you really are concerned with house plants, I'd recommend you pick up a
copy of "Crockett's Indoor Garden". It's out of print, but you can get used
copies CHEAP at www.powells.com.