Genesis 1:11-13 - Plants

¹¹ Then God said, “Let the land produce vegetation: seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds.” And it was so. ¹² The land produced vegetation: plants bearing seed according to their kinds and trees bearing fruit with seed in it according to their kinds. And God saw that it was good. ¹³ And there was evening, and there was morning—the third day.

http://www.blotspace.com/plants-vs-blotspace/

Then God said - Unless God has spoken, the earth would have remained barren, an there would be no life on it. All of creation owes its existence to God, he deserves all praise and glory.  
'“Let the land produce vegetation...' - We see that God created the plants before creating the sun and the moon. This is a reminder to us that God can do anything, he is all powerful and can do the impossible. We too often think God is weak, that he cannot do things without help, for example - that he cannot create plants without using the sun. We are reminded that God can do anything, he doesn't need the sun to make plants grow. Likewise, God doesn't need us to accomplish his will, but he chooses to use us for his glory - in spreading the gospel and serving him. It is an honour to serve God. 
 God created all things for his glory, we are blessed to be able to enjoy his creation, We should use it for his glory, and thank him that he has given us so much.
'...seed-bearing plants and trees on the land that bear fruit with seed in it, according to their various kinds.”' - We also learn that God not only created plants, but gave them the ability to reproduce. God set everything to work, so that it would continue onward until he stopped it. The world works because God made it to work, he made everything perfectly. There will come a time though when God will judge, he will destroy the earth and all who are not his because of our sin. Repent and Believe and be saved (Revelations 19:20-21, Joel 2:32)
'And it was so.' - God is all powerful and is able to bring about what he plans. We must trust him. What God says he will do, he does. He keeps his promises (Matthew 5:18) and does not lie (Numbers 23:19). 
'And God saw that it was good' - God does everything perfectly, he himself is perfect and good (Psalm 119:68). As of yet, there was no sin in the world, everything was good. 
'Evening and Morning-the third day' - Again, it was a 24 hour time period. (As far as we can tell from the bible) - God can do whatever he wants. He is powerful enough to do it in 24 hours (In fact, he is powerful enough to do anything in any time frame), so why doubt that he created in 6 days which were literally 24 hours?