Spider mites are eating my 5-year-old Norfolk pine. I have never had this problem before but recently moved to another area of the state.

I have tried blasting them with water --maybe some luck.

Yesterday, on advise of my nurseryman, I purchased liquified seaweed and orange oil and sprayed the tree this morning.

Any other suggestions?

What area of the state are you in now? Norfolk doesn't sound like an adapted Pine. I see no reference of it in Howard's book "Texas Trees". The only thing I can think to suggest is an application of horticultural cornmeal and the sick tree treatment.
http://www.dirtdoctor.com/pics/documents/SICK%20TREE%20TREATMENT%20HANDOUT1.doc
Remember that the spider mites are a secondary problem. Nature has a way of putting things the way they should be by taking out ill adapted or diseased plants. Check out the quote in my signature below. It speaks volumes.
Good luck to you!