Clay soil. *Ugh* I have that in the back of my property. Old roses will do well. So will fruit trees. There are a couple ways to go about it. Sand is the best but will be back breaking hard to mix in without powerful equipment. I have done my planting in clay like this.
I think about the plants I want and dig holes three time larger than the root ball or pot. I consider that plant having to live in a pot while it's in the ground. The outside edge of the clay soil will be like the walls of a pot. In this hole I will put the compost, a bit of sand, or my secret recipe for growing. (more on this later)
It will take fruit trees about three to five years to fill the hole before their roots start to break into that clay down there. Roses will start thriving faster. The most important thing about growing in bad clay soil is water retention. If standing water sits for too long over the tops of plant roots, they will die. Excellent drainage is crucial.
If you have the time, building raised berms or beds over the top of clay soils will work too. Where does water drain? That is what you need to know. Turn on a hose over the spot you are considering planting. Which direction does water flow? Will it flow towards your house, coop, the neighbors?
You can dig out a test hole. Fill it with water and time how long it takes to seep away. If water is still in that hole a day later, you've got a problem.
I think I may have a problem with water because last year we had rain for months on end and the water remained on the surface for days but we were experiencing flooding in many parts of the country so I will have to see this coming winter.
I will definitely look at planting some fruit trees as I would love to have some in my garden. I like the look of the dwarf apple trees - do they hold there own with snow and frost?
I definitely want to get some roses as well.