Warm welcome from the Pacific Northwest, alinadunc. I just use a general pelleted organic fertilizer in the early spring when plants are emerging (when I remember) and sometimes after I have cut my perennials back after blooming (again when I remember). I sprinkle it around the plant and either scratch it in or cover with a compost mulch. I tried being more specific (e.g., something wants bloodmeal, something else wants kelp) but found the boxes/sacks just slowly melted into my storage bench and became infested with weird bugs. I can't speak to your specific plants, which seem to be more tropical (way out of my zone), perhaps they need a better boost? I try to stick to natives or easy-care plants to cut down on coddling.
