Identify the obscure horror movie

[Jomb]

Its the Halloween season, and no one would be better at this then the people here, so...

When I was a kid (probably between 5 and 7 years old), I saw some movies which scared the hell out of me, but have no idea what they were now as an adult. I did'nt see them in theaters, I saw then on TV at home late at night. This would have been in the early 80's, so they cant be made later than say 1985. They may have been made for TV, or they may have been regular movies being played on TV. They may have been on regular TV or have been played on HBO during the brief time we had that. I already possibly got one of them identified in another thread.

Here is the most baffling one though: I only remember bits and pieces of this thing, but was very impressed by it. The main character was a young girl, maybe in the 10 to 14 year old range. In the movie she was wandering around in an eerie countryside. I think she was lost and trying to get home. She was on a schoolbus and at night it got stopped in the country and a bunch of zombies came out and surrounded it and were breaking into the windows and killed the driver and many other people on the bus. She managed to escape. There is a scene where she stumbles upon a large old victorian home and there is an orchard in the back yard. She is in the orchard and in the distance she sees a zombie running towards her. She climbs up a tree to escape from it and it is below mindlessly jumping and reaching for her. She is trapped in the tree. Then an aristocratic looking old woman comes walking over and she orders the zombie to stop and to go away. It listens to her. The old woman helps the girl and takes her into the big house. She is being nice to the girl but I think she has an ulterior motivation. I dont remember anything else.