is it reasonable to think that some additional fertilizer is needed

Definitely, additional fertilizer is needed, excess water or not, given the way you are building your beds. Given all the extra rain water then granular/powdered ferts will work better than adding more liquids or foliar feeding.

Is there any danger to adding regular foliar feeds and handfuls of dried compost worked into top soil more often?

Not at all but the benefits would be minimal since you have only a minimally developed soil micro-herd to convert them to useable nutrients. Organic soil amendments like compost and manures are just that, soil amendments, not fertilizers. Without a highly developed bacterial herd to convert the nutrients in them the plants can't use them. And with new beds each year the soil bacteria are minimal.

Consider either adding large doses of micro- and macro-bacteria supplements each year or use granular/powdered organic fertilizers.

Dave

Dave, what would be your suggestions regarding bacteria-flora supplements?

There are many available on the market and the choice is basically yours. Since you are working under a time constraint you will want one with high levels of live bacteria. See the link below for just some suggestions and even more info on them is available on both the Soil & Compost forum here and the Organic Gardening forum here.

You can also make your own to have next year by starting a very active diverse-ingredient compost pile now so it is available to add to the plot soil much earlier next year. Of if you have year round access to the plot, sheet composting there.

6 weeks just isn't long enough to develop sufficient activity in the bed.

Dave

Here is a link that might be useful: Microbial Innoculants

Can't you have the same plot each year so you can work on the soil? Lasagne garden in the off season (or does it just get covered in snow?)? That would make sense to me, but I live where there is year round gardening! Nancy

Yes, generally they will assign same plot year after year, but one has to remove-disassemble everything and village will rototill everything after the season and before the season starts. So there is benefit in adding to the soil just not the same I would have done otherwise.

Fertilizer is a general term . Essential general all-purpose fertilizers contain N, P, K( Ninitrogen, phosphorous, potassium ). Of those three, Phosphorous stick to the soil and stick around for a long time. Nitrogen, being readily water soluble, has tendency to be leached out. Potassium (K)is somewhere in between.

Therefore, in container gardening and also during and shortly after prolonged rains, it is mostly the nitrogen that becomes deficient as evidenced by yellow foliage. Under such circumstances I feed mostly Nitrogen, maybe some Potassium(K) but not much Phosphorous. If you cannot find those elements separately, use a fertilizer that is rich in nitrogen but poor in phosphorous with some potassium.

Also, I often just give nitrogen to my leafy veggies that you don't want them to flower and fruit. But K is essential for roots . Wood ash is an excellent source of potassium if you can get it.