Hello.
I need help making a latch program for a capacitive switch.
Its a pin heading to a plant.
My intention is that when i touch a plant, an LED turns on.
But when i touch the plant again i want the LED to turn off.
Hope you can help me. Since im a begginer to Arduino.
Hi,
Welcome to the forum.
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http://forum.arduino.cc/index.php/topic,148850.0.html.
How are you getting capacitive touch?
Arduino software or capacitive touch module?
Have you googled
capacitive touch sensor arduino
I can see you having problems with using a plant as the touch element, just the fact that it is in a pot/plot of soil and that will change conductivity with soil moisture.
Change in conductivity will mean your capacitance will change without touching it.
Even the wire from plant to controller will effect the operation.
Tom... 
Having had difficulty getting the "capsense" library to work to my satisfaction - though others may have had more luck - I recommend using a TTP223 sensor for the job.
eBay!
This module has a "touch" pad on it, but you simply connect a wire to the same terminal on the other side of the PCB (the right-hand dot above the IC in that picture) to your plant to make it the "touch pad".
Note this module should be mounted as close to the plant as possible - under its dish would be perfect!
You jumper the "B" link on the module to set the "toggle" function you want - one touch on, another touch off. The "A" link sets whether it is on or off when your power supply is turned on (or a battery is connected).
You will however need a transistor (with a series base resistor) to switch your LED as the TTP223 cannot source more than 3 mA. You do not need an Arduino.
This is a minimal cap sense project that works and can take modifying the sensor.
https://playground.arduino.cc/Code/CapacitiveSensor/
I have a paperclip bent around and foil added to make a surface on a stick. That works better than a bare pin for detecting "close finger".
I have bent the legs of a .1 MF cap outward and stuck one in the Uno hole. I touch the top lead and it reads.
The idea behind the cap is to absorb some amount of spike and keep my board pin safe... maybe it does.
I added the clip and foil on top of the cap and it works.
So if you keep the Arduino close to the plant, I expect that the plant can be your sensor if you stick the contact into the plant far enough to hit sap.
When you do this, see what getting drained to ground then charged to about 3V some number of times per second does to the plant.