Question
I live 50 miles south of Sacramento and have several established trees in my yard, including a magnolia, olive tree, crepe mertal and  another I do not know (this is my first time tackling a yard). Unfortunately, there is also 20-year-old (I assume) creeping juniper throughout as a ground covering. I am in the process of removing the juniper in order to put in a lawn from seed. My question is... how do I remove the juniper roots? I don't particularly want to break my back, but I'm willing to if chemicals will harm my future lawn or trees. If I attempt this removal with a shovel, though, how do I keep from damaging the roots of the trees I want to keep? Also, any advice on how to prep the soil for grass after this past life of juniper and weeds?

I'm having a difficult time finding information on this, so thank you for any advice you can give me.  

Answer
The most important part is ripping up the juniper near the soil level. Most trees have an extensive root net and can accept a fair amount of damage with no impact. Just avoid cutting major roots near the base of the tree. SOme root pruning of the tree is acceptable.

Since the tree and the juniper likely shares the root net I will not recommend Round-Up (glypsohate) which is normally recommended. The product is sprayed on green actively growing leaves and then translocated within the plant to the roots where it kills the plant. While the product is not mobile or resistant in soil, plants which share the same vascular system can be impacted.

The best way to avoid herbicide injury in these cases is to sever the roots so herbicide can't travel. This is best done by professionals with experience using a vibratory plow, a machine that slices the soil deeply around the shrubs to be removed.

I would probably continue to use the shovel, ax and spade to cut the main roots achoring the junipers. Don't worry about some damage to tree roots. Then skip on the herbicides.

After removing junipers, loosen the top 6-8" of soil and if possible bring in and mix 2-3" layer of compost or good organic topsoil into the top layer. Then rake smooth and water to settle the lawn. At this time, a soil test to find out if any nutrients are missing and the pH is suggested. It is often easier to correct any nutrient deficiency or change the pH before the turf is established.