I would wait to find out what elements are lacking before applying anything. However, I am no expert at this ( only am relying on personal experiences) and there are many in this group who are better equipped to answer such questions. I have added various elements to improve the soil over the years. Iron chelate is readily available, and I have added that to improve iron deficiencies. Magnesium Sulfate (Epsom salts) is good to apply to soil around roses, and this can also help if your soil has a magnesium deficiency. Epsom salts are good because they usually don't change the soil PH.