Can we get double upgrade in plants vs zombies 2

Here is a table from Plant Food:

Peashooter: Turns them into faster-shooting Gatling Peas for three seconds. They shoot approximately 20 peas a second.
Sunflower: Produces 150 sun.
Wall-nut: Gives it a hard armor shell for extra strength.
Potato Mine: Arms itself and produces two armed Potato Mines on other spaces.
Cabbage-pult: Launches several cabbages at once, hitting every zombie and grave onscreen.
Bloomerang: Shoots approximately ten boomerangs in four directions, up, down, left and right.
Iceberg Lettuce: Freezes every zombie on screen, similar to the Ice-shroom.
Twin Sunflower: Gives 250 sun.
Bonk Choy: Punches zombies in every direction at a very fast rate.
Repeater: Shoots like a Gatling Pea at first, but at the end it shoots a 2x bigger Pea.
Kernel-pult: Launches several butter at once, hitting every zombie and grave onscreen.
Snapdragon: Sets a 3x3 area in front of it on fire killing all zombies on those spaces.
Spikeweed: Temporarily fills the row with other spikes poking up from the ground and pulls zombie to the Spikeweed.
Coconut Cannon: Fires one big Coconut that kills all zombies in a row.
Spring Bean: Bounces all zombies on screen.
Spikerock: Temporarily fills the row with other spikes poking up from the ground and pulls zombies to the Spikerock.
Threepeater: Shoots a wildfire of peas across the area.
Split Pea: Both heads shoot peas like fast-shooting Gatling Peas. The Repeater head fires a big pea at the end.
Chili Bean: Launches 3 extra beans randomly.
Lightning Reed: Makes a storm cloud that damages the zombies with lightning.
Tall-nut: Gives it a hard armor for extra strength like Wall-nut.
Pea Pod: Gains a giant Peashooter head that shoots five big peas which do a lot of damage.
Melon-pult: Launches melons out from the top that does 2x the damage to all zombies.
Winter Melon: Same as Melon-pult with added slowing effect.
Imitater: As the Imitated Plant
Snow Pea: It shoots a lot of frozen peas
Torchwood: The fire becomes napalm.

For full information there is the website above.

Per the official Support page (click on the "How do I get more coins?" question):

You'll use the Coins to purchase extra Plant Food and Power Ups!

That's all they are used for.