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Joined: Wed Apr 10, 2013 4:09 am
Location: Belgium

Fertilizing tomatoes

What do you use to fertilize your tomatoes with?
Is it a good idea to use 2 different fertilizers?
I'm planning to use Chili Focus and BioBizz fish mix....and a little bit of vinasse.

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Joined: Sun Sep 26, 2010 1:10 pm
Location: ID/WA! border

I like those names but don't think I'm going to find them here, Itoero :).

Try for a balance altho' I personally don't think there is any harm in giving the plants a higher start with extra nitrogen. It is good that the plants get some growth in during the early part of their season.

A good gardener I know who grows only tomatoes had what seemed to me, reasonable advice. She said she did what her grandfather told her was best and put down 50 pounds of composted cow manure in the ground for each plant. The nitrogen-phosphorus-potassium numbers I have seen for composted cow manure are something like .5% .5% .5%. You won't find that on the bags since the company is making a claim for its fertilizer value and it varies, I'm sure.

The lady has livestock so she doesn't quite follow what her grandfather did. She does give the plants quite a lot of room in her garden.

That balance looks good but I just use a bagged organic fertilizer and may use fish emulsion early in the season. None of it is as heavy to carry around as all that cow manure.


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Joined: Tue Jan 01, 2013 8:32 am
Location: Hawaii, zone 12a 587 ft elev.

Good advice.

Tomatoes are heavy feeders. Compost worked in to the soil is always a good start for planting everything.

Some people also like to add some calcium to the planting hole as a hedge against blossom end rot. I don't do that, but it doesn't hurt. Making sure tomatoes are evenly watered does.

Tomatoes need a moderate amount of nitrogen, a higher phosphorus and a moderate amount of potassium.

How much do you really need is determined by your soil test. If you ask for specific recommendations for a particular crop, the soil test will also provide recommended amounts of fertilizer to add and if you have to make any adjustments to pH.

Too much nitrogen will give you a large healthy plant but at the expense of fruit production.

Not enough, the leaves will be yellow and the production will be low because the plant isn't going to be very big.

Phosphorus that is too high can make micronutrients unavailable

Potassium helps with the plant's resistance to disease and supports growth.

I usually mix half the fertilizer in the planting hole or bed and side dress at the first flowering, again when the fruit is half grown, and monthly thereafter. The higher the number the less fertilizer you need to apply. It comes out to anywhere from 0.5-1 pound per 100 square feet. It is better to get the lowest nitrogen you can find. Nitrogen does not last long in the soil, it is quickly used up by the soil and bacteria, volatilizes off into the atmosphere, and too much will actually keep seeds from sprouting. Most of the nitrogen should be applied as side dressings during the growing season. The total nitrogen requirement should be divided over the course of the planting. I usually give half the nitrogen at the start and 25% in 30 days and the remainder 30 days after that for a 90 day crop. Most of the nitrogen is needed to support the early growth of seedlings. Water soluble fertilizers are applied every two weeks instead. It is more expensive but it works very well.

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