She likes to do gardening so she has two garden hoses attached to two outlets. 

But, all you have to do is get a list of handymen, plumber, electrician, gardeners, etc., you can call if there's something that needs fixing.If the market is tight for buyers, it is probably also tight for renters and you could probably get a good tenant in there easily.You just need to be picky when you are screening. 

One of the room mates did mention during the tour that she did but heads with the landlord sometimes because he hired landscapers to tear up their garden/didn't allow gardening, etc.

(Who would want to build garden apartments, when cap rates were so low in these new up and coming cities- hence 18 hour, and not 24 hour cities ;) So now those buildings will offer discounts, etc., and may also attract some class B tenants from the garden buildings.

., family of 5, 3 dogs, 2 cats, 16 chickens, veggie garden and grass in front and back and mine is usually $150 during the summer.

This one seemed to match pretty well to the above: https://www.overstock.com/Home-Garden/Simple-Living-Antique-White-Frosted-Pane-Wall-Cabinet/6356567/product.html?

The downstairs, it's a garden-level, needed renovation.

My second question is, can I take money out of their security deposit to pay for garden maintenance since they neglected the gardens around the house and didn't mow the whole yard.  

Then, include a gardener in your rent and require the tenant to let the gardener take care of the backyard.With a lawn, it's just a matter of mowing and weed-eating the edges, & leaf-blowing leaves into piles in the fall.  

I also like your idea of the gardening/landscape renovations!