See if you can find sulpomag or kmag in your area. That will give you potash (potassium). Blood or feather meal for nitrogen. Look at farmer's feed stores.

How much organic matter is in your soil? Low levels of Nitrogen may just be seasonal since the soil bacteria are not very active in cold soils and they make Nitrogen available to plants.
What to add depends on what is missing. was that soil test from a good reliable soil testing lab or one of those soil test kits from the garden center, one that really tells you little or nothing and is often not very accurate?

Kimmsr, in the cold season, I use a foliage plant food. But, it is real pain. The sprayer gets clogged all the time. My plants grow all year around even in winter. But, if the plants are dormant it won't matter if the nitrogen is low, if it like snowing or something and you don't want them to grow.