Automatic watering of vegetables

Hi!

i want to chose arduino, but i need recommendations.
I grow vegetables and i want to make automated system.

Vegetables needs these:
-watering-periodically, once a day
-temperature mode - if the temperature has dropped below 20 degrees, increase to 25
-light mode - need 15 hours of light. When it gets dark for 2 hours to turn on the light bulb

How to make such an automated system? What kind of card i need, what elements.

Thank you in advance

opowerblast:
-watering-periodically, once a day

You will probably want an RTC, which is a clock that will allow your Arduino to keep accurate time

opowerblast:
-temperature mode - if the temperature has dropped below 20 degrees, increase to 25

Look at thermistors for a temperature sensor. There are also DHT sensors that are popular for use in measuring temperature and humidity.

opowerblast:
-light mode - need 15 hours of light. When it gets dark for 2 hours to turn on the light bulb

Look at photoresistors.

You will also need a solenoid valve to turn the water on and off and the components necessary to turn that solenoid valve on and off. You also need power supply, enclosure, mounting hardware, etc.

opowerblast:
What kind of card i need

Any sort of Arduino will work. I'd consider the Arduino nano. If you want a networked device you might consider the ESP8266 instead because it has built in WiFi.

And a relay or SSR to control the lights!