In article , l loi wrote:
Can you feed plants starch?
Is it good?
My friend says his mum used it on plants and it was great.
The water drained from the spagetti, or water from boiled potato

Cooking water has other stuff in it besides starch, including minerals
and some protein and vitamins, which can provide nutrition for plants
after they break down. The starch may also encourage soil bacteria,
which release plant nutrients from organic matter in the soil.

This isn't as good an idea if you salt your cooking water.

When it comes down to it, house plants usually need very little in the
way of plant food, since they usually get little light and grow
slowly. People like to feed their house plants, and feeding them
dilute stuff like this is gratifying and can provide the plants with
the minute quantities of NPK they need under these conditions. People
often over-fertilize their house plants with chemical fertilizers, so
folk methods like this may be preferable.

Another thing people like to feed their house plants is leftover tea
and coffee. This works pretty well (coffee provides a surprising
amount of nitrogen), and adds stable organic acids to the soil, which
is good since potting soil tends to get alkaline in hard water areas.
If you use milk in your tea or coffee, do this only seldom or you'll
have a stinking mess.

Personally, I use pasta water as stock when making soup or for starting
a sponge when baking bread. The yellowish color is due to the B
vitamin riboflavin, and the liquid contains other vitamins, especially
those added to enrich the pasta. This is a growth stimulant to the
bread yeast. I haven't boiled potatoes in decades -- I usually nuke
them in a casserole in the microwave. I don't peel them either. Life
is too short, it's true that a lot of the nutrients are just under the
skin, and just about everybody can use more dietary fibre!

I sometimes water my house plants with water from my aquaria. This would
count as very dilute manure tea, and works great.