They are tough plants. You might do better to take cuttings (6-12" long) next spring, stick them in the ground where you want the shrubs to grow, water, and wait. They root readily! If you have a sheltered area to overwinter them, you can try taking cuttings now, putting them in pots and keeping them sheltered over the winter - not so much so that they don't stay dormant, but so the roots aren't frozen hard and killed - in a shed, a garage, buried in the ground or in a mass of leaves should all work. Keep them damp but not soggy, else they will rot. Don't try to keep them indoors, it will be too warm and dry, but a cool greenhouse/cold-frame should work also. You CAN try to move them as well, and probably have good luck, as far as the basic technique for moving affects forsythias. I am not sure when the ground freezes where you are - z5-6 covers a wide area - but if it isn't for another 6 weeks or so, then you can cut them back to where they are handle-able, and try to dig them now, or wait until spring, as soon as the ground can be dug. Since they are old, and are growing under an oak tree, the root system will be pretty massive and hard to dig. Either way, you will loose the blooms for next spring, since you will be cutting them back, but you will either get them moved, or get them out of that spot. Pre-dig the holes for where you want them to go, fairly shallow, but very wide - don't amend the soil, and water and mulch well after re-planting them. Doing both - cuttings and moving - would be insurance that you will still have forsythia in future years.

The more rootball you can get the better. The key thing is to reduce the top growth (above ground) by the amount of root system you lose. For example, if you get only half of the root system, prune off 1/2 of the top growth. If you get 3/4 of the root system, prune off 1/4 of the top growth. This way you are not stressing the plant so much. Another thing: try not to do the move during a spell of very hot weather. Extreme heat will further stress the plant. If you have a patio umbrella to shade them for a few days after the move, that would help. Another thing: keep the moved rose well watered, especially for the first few weeks. Now, don't overdo it and drown them, but make sure the soil is moist at all times.

Hi, gentlemen, I had to chuckle at the reference to "grandma". Indeed I am. However, in very recent years, my husband [grandpa] who is about 130 lbs. and myself as assistant planted trees with rootballs 100lbs.+, all of which survived beautifully. Physics [my husband] has a lot to do with it when brawn is not possible, plus common sense re watering [my department]. Appreciated the tip on width - my husband may have already thought of that - and also the idea from the link of watering foliage as well as the rootball. I had been wondering if there were things to be aware of that I could pass on to my husband. At any rate you have encouraged me. Perhaps I can let you know how this turns out. If we end up attempting it, it will be in 3-4 weeks.

I would love to hear your helpful tips on how to dig up and move/transplant an established clematis vine. It is in Group#3 Probably right now would be a good time as I prunned it all the way back in the late Fall, so it hasn't started sending up new growth yet. Gosh, I had better doublecheck on that today. I'd hate to disturb it if it has started its new growth. The previous owners planted it right on the corner of the garage/brick facing. How long ago, I have no idea.