OK folks - here's the challenge: I have a high backed sofa that is

[hedgehog]

not going to be replaced until after my youngest graduates college. I need an over sized throw to put over it since the upholstery is in bad shape. Regular sofa throws won't do it because of the high back. The sofa has T-cushions, so most slip covers won't fit. Something washable in forest green would be ideal.

[Whoa_Nelly]

1. SureFit has T-cushion slips

http://www.surefit.net/shop/category/t-cushion-covers/?ssz=Sofa&lni=402,4&UseSize=Sofa

And a bunch of others:
http://www.nextag.com/t_-_cushion-slipcovers/search-html

[jillan]

2. I used Sure-Fit on a T-cushion sofa.

It looks really good. I recommend getting the stretchy material.
Cost me about $100 BUT that is still cheaper than a new sofa.

[Warpy]

3. Failing taking an upholstery class

what you can do is get some upholstery material three times the length of the couch, cut it in half, seam it lengthwise, put matching or contrasting fringe on the edges, and use it as a throw to cover the whole thing.

It's not ideal and will require frequent straightening, but it's a way to disguise all the holes and stains until you get rid of the kids and get a new sofa.

Plus, it's cheap.