This is a dilemma that many of us Ham Radio Operators Face, The Small Backyard. I myself have suffered from this my whole life. When I was younger, living at home, we had very little space. What I did was to look over the area and then use my imagination. Now this was back in the late 70s and cb radio was very popular. I had a few different cb antennas over the years.
I started out with a magnet mount antenna on a metal tv tray. Needless to say, it did not work very well. I bought a used 1/2 wave ground-plane antenna from a friend. I wall mounted it to the side of the house and it did a pretty good job. I wanted to reach further, so I bought a full 5/8 wave ground-plane antenna and mounted it on top of the roof on a tripod. It was basically just like the super perpetrator.
Well I still wanted to make further contacts, so I bought a 40 foot tower and a pdl II beam antenna. I cemented the tower on a hinge system, wall mounted it and had guy wires. Basically it was not going anywhere. The backyard had a small oval pool and very little space, but I did it. I did have a star duster antenna that came crashing to the ground. Later I did but a big stick antenna on the roof and it was good for local talk. I did get some excellent distance with the beam antenna.
Now I was married in 1984 and we moved into an apartment. Now all I had was the mobile antenna on the my truck. We were in a townhouse for awhile, but no place for an antenna. In 1992 we bought a house and I had the 5/8 wave up and it did an okay job. I eventually got my Technician Ham License and then my General Ham License.
I bought a imax 2000 vertical antenna, that can be used on cb radio and some ham bands. I also installed a multi-band dipole antenna, with the apex at about 35 feet. It did a good job until the bands faded out as the seasons change. The problem I have is that the backyard is small, maybe about 25 foot from the back of the house to the fence. The west side of the house has the power lines running through the middle and the other side has the driveway. The front yard has some space and 4 trees.
Unfortunately I sold the 40 foot tower awhile ago, which I never should have. I have some hamstick antennas I am playing with. I also have a mfj cobwebb antenna that I would like to put up. I have a vertical 6btv, but the trees have grown and I am not sure how it will work with the trees. I would have to lay some ground radials down. The weather has gotten cold and I have to think about things.
So if you are looking for some small space ham antenna ideas, here they are. The cobweb antenna is multi-band and works very well. Using Hamsticks is another good choice, especially with the mount by mfj. The comet cha250b is a good choice for a vertical antenna. I would also check out youtube for small space ham antennas.