riley said:

I had a basic soil test done by Penn State Univ.

You've done something to many don't do. Well done!

I live in west
central PA and the soil seems to be mostly clay. The results showed a
pH of 6.0 with low potash. PSU recommends a 0-46-0 fertilizer to
correct the low potash.

I think you need to read your soil test and recommendations again. The
middle number in a fertilizer analysis is *phosphorous* and potash
(potassium) is the last number. What exactly are they recommending?

And did they measure the % of organic matter?

I want to grow mainly native deciduous shrubs
and some small flowering trees. Once these are established I may look
into some perennial beds, a vegetable garden, roses or wherever my
horticultural interests takes me.

For the vegetable garden, roses, and flowering shrubs you will almost
certainly need to do some soil ammending and fertilizing. Native shrubs
and trees (if they naturally grow in your soil conditions) mightn't want you
fussing at all.

So, in the end...it all depends! 8^)

I am new to the gardening thing and would like some advice on how
best to apply the fertilizer. Would I just add it to the planting
holes or do I need to address the entire area?

For trees and shrubs, the usual recommendation is *not* to add fertilizers
when planting, or even do much soil ammending. The best advice would be
to choose varieties suitable for your soil conditons. The same would go for
completely naturalized perennial beds; pick the right plants for the soil and
climate.

For vegetables and more intensively managed flower beds, you add soil
ammendments (compost, fertilizers, possibly even lots of sharp sand to
help with the clay) when creating the beds. Then you plant into them.

Should I do this at
planting time or do it now and allow it to work into the soil over
time? Any advice would be appreciated.

Surface applications are prone to runoff and some nutrients are leachable.
Just scattering stuff around now when your plans are for later is probably
not wise, in my opinion.

The test also noted that magnesium and especially calcium were above
optimum levels, but no recommendations were made regarding this.
Should this be a concern before I spend money on trees and shrubs?

There is some interplay between phosphorous and magnesium, but if
you do need to correct the middle number (rather than potash), the lab
recommendations have already addressed that.


--
Pat in Plymouth MI ('someplace.net' is comcast)

Any technology distinguishable from magic is insufficiently advanced.
(attributed to Don Marti)