planted some white pines 2 years ago used 10-10-10 fertilizer early spring , there still not as dark green as they should be. there growing good..also can i use a heavier fertilizer on them?
Might be too much fertiliser. They are adapted to growing on low nutrient soils in the wild. Just let them grow on their own. Check that they weren't planted too deep or anything (the root flare should just be visible).
I'll add to what Michael said, that the native soil should provide adequate fertility, and warning that a too deep planting could become a problem (dig out about the base until you can see the root flare). The main reason I see that white pines aren't "real green", and can even cause yellowing if it is way off, is that the soil pH is too high. The soil needs to be acidic for the tree to be able to uptake iron (Fe). You could find water disbursable sulphur granules and spread under the tree to help a little. Better would be to test the soil pH before planting and make an adjustment then.
thanks for the info. when i bought the trees i was told to fertilize once a year with 10-10-10- i have used holly tone on trees and bushes before to get theme greener. mabeb pines wont like it.. i did plant some other norway pines at the same time i planted the white, and there growing and green as can be..
Nutrient content of soils varies. Blanket fertilization recommendations are erroneous. In some districts soils vary right on the same building lot (same soil also varies seasonally).