Hi,
I have some very basic questions regarding managing products in a store I am building for a nursery.
We will have products like this for example:

LIVE Oak Tree, Green, 1 Gal - $ 10
Live Oak Tree, Green, 15 Gal - $ 50
Live Oak Tree, Green, 30 Gal - $ 100

Red Oak Tree, Green, 5 Gal - $ 12
Red Oak Tree, Green, 25 Gal - $ 54
Red Oak Tree, Green, 50 Gal - $ 200

Knockout Rose Flowers, Pink, 3 Gal - $ 14
Knockout Rose Flowers, Pink, 5 Gal - $ 24

Knockout Rose Flowers, Red, 3 Gal - $ 11
Knockout Rose Flowers, Red, 5 Gal - $ 34

Gerbaras Flowers, Yellow, 5 Gal - $ 4
Gerbaras Flowers, Red, 5 Gal - $ 20

Gerbaras Flowers, Yellow, 10 Gal - $ 24
Gerbaras Flowers, Red, 10 Gal - $ 34

INSTALLATION is offered only for TREES.
There are two types of installation. When TREES are installed on FRESH GROUND or if they have to REMOVE EXISTING root system and then install the tree[s].

So a) FRESH INSTALLATION b) REPLACE EXISTING/ INSTALLATION.
FRESH INSTALLATION has one price and REPLACE EXISTING INSTALLATION has another price.

So far, I have figured out the following:

Categoriers:
TREES , FLOWERS

PRODUCTS:
Live Oak
Red Oak
Knockout Rose
Gerbaras

ATTRIBUTES:
Container Size with values  1 Gal, 3 Gal, 5 Gal, etc....
Color with values Green, Red, Yellow, Pink

Checkout Attribute:
I initially though of making INSTALLATION as as CHECKOUT attribute. However, how do I make it take 2 values with its own price, and only showup when the cart contains any TREES. Is there any other best way to handle this?

My question is, how do i create the product mapping with PRODUCT VARIANTS / PRODUCT ATTRIBUTES / SPECIFICATION attributes, i.e. the whole nine yards.

I fully do not understand what PRODUCT VARIANTS are and how they fit in this model.
For me, each of the above is an SKU item.
i.e. for a combination of product - color - size = SKU Item with its own price.

So please help me understand how to MANAGE MY PRODUCTS in this store.
I am very new to NC and am a great fan of using this for my project.

Much appreciated.
And thanks in advance.

Regards,