Annual seeds like asters, marigolds, zinnias and cosmos can be planted now.
You can start sowing annuals in the open ground, prime examples would be marigolds or annual poppies.
Hardy annuals such as Calendula can now be sown! About Calendula and its use: http://j.mp/Q23ZJS
Do you grow begonias? They can be annuals, perennials or shrubs! About some begonia varieties: http://j.mp/O8nSNH
Honeywort Purpurascens is an annual with blue-green leaves! It is supposed to be slug-resistant: http://j.mp/NZ6gP1
Do you have gaps in herbaceous borders? Fill them with annuals! How to pick the perfect plant: http://j.mp/KWSs6t
It is not too late to sow hardy annuals such as marigold in the garden! About growing this plant: http://j.mp/KOoerK
The last average frost date has passed! Time to plant warm season vegetables and annuals: http://j.mp/L2lUev
Sow hardy annuals such as California poppies now! About some varieties of this annual: http://j.mp/HQQoig
Now is a good time to plant hardy annuals and herbaceous perennials! How to start a flower garden: http://j.mp/HxArOp