Well seems nobody wants to take on the question, The short answer is "it depends." It's actually a really good question. Nobody really knows the answer. They base how they do it on observation. Some, water beforehand then water with fertilizer. I feel if doing 1/4 or 1/2 doses ones does not need to do this. With diluted doses I water like you would if no fertilizer. Saturate till it runs out. Better to water heavy at longer intervals than to water a little at shorter intervals. this is the accepted practice, and why would you change it when adding fertilizer? I'm sure others have their on way of doing things. You yourself have to decide what works for you. Many here advocate a one size fits all approach. Same fertilizer, same dose for all plants. Through decades of observation I have found this to be invalid. Some say the ratio is the same for all plants. Again, this is not true. Uptake of nutrition varies by plant family, sometimes even within a plant family. Nutritional adaptations for each plant group do vary. Some use bacteria to help, vascular plants use fungi, well 90% do. Some do not like Cabbage. Some convert animal protein to nitrogen, Using chemical fertilizers can easily kill them. Some can move nutrients both ways root to shoot, or shoot to root. When you asked about foliar feeding, well it depends if the plant you are feeding has the ability to move nutrients from leaves to roots.If it only feeds the leaves, other parts of the plant could be at a deficit. In a nutshell, how you feed a plant, what doses to give, what ratios work best depends on what you're feeding. Because of this I myself have decided to just feed the soil, and the plant can take what it needs.. Most soluble fertilizers damage the soil, so I don't use them. It really is near impossible to know if you're giving enough or not. I would suggest to follow label instructions. and modify. Say it calls for 1 tablespoon per gallon once every two weeks. And you water your plant once a week. So give 1/2 dose at each watering.Still I don't trust the labels that much. So I'm moving away quickly from chemical fertilizers. I prefer a liquid organic like say Sea Mate. It was easy to switch to organics using liquids for house plants. It also requires a change in soil makeup. Each grower has to decide what works for them. With cacti, which I grow. I have been hesitant to do this as pretty much exact doses and ratios for cacti have been figured out via various studies. Following study findings I have had great success, so I may stick with soluble for them. I don't use foliage pro as the ratio is incorrect for my methods. I have said this before and others came forward calming great results with foliage pro. Sure they will grow fine with this, but they will grow even better using study supported techniques. I have no desire to tell people what to do, we are all adults here, do what works for you, and I'll do the same. I like my method of using 2 different fertilizers as I'm also trying to keep soil somewhat acidic, It works for me, use what works for you. Hopefully I answered your questions. Good luck!

There isn't a "best". There are many many goods ones but no best as it all depends on what your approach to gardening is (organic or not) and what your soil may need and the only way to know that for sure is a prof soil test. Is that possible? Compost is always a good soil amendment but it isn't primarily a fertilizer. It can provide nutrients IF you have a well established and active soil bacteria level. Manured compost (never fresh manure) is better IMO as it contains more nutrients but the active bacteria (called "soil food web") is still required to make the nutrients available to the plants. If this is in ground those bacteria are there but need several season of work to kick into high gear. If in containers the bacteria doesn't exist unless added regularly. There are many forms of supplemental synthetic fertilizers available if you aren't devoted to growing organically and the liquids are only a small part of them. The liquids - used per label directions - work well in containers but in in-ground beds are just a quick-fix as they disperse away from the roots fairly rapidly. The dry granular supplements stay in place and decompose slowly slow provide a somewhat slower but longer duration of nutrients. I don't know what sort of dray granular supplements are available to you in New Zealand but if I were you I'd explore local sources for them. Look for something with a rating of something like 10-10-10 or something with a higher first number for the nitrogen leafy vegetables you are growing, say 15-12-10 or that range. Also keep your eye out for some of the bacterial supplements that can be added to soil so the the compost can work more efficiently. Hope this helps. Dave

AS=ammonium sulfate. The organic compounds of the fertilizer are slow release while the synthetic ones would act way quicker. Again you can use any fertilizer that is formulated for acidic loving plants such as azaleas, camellias, rhododendrons as they all belong to the ericaceous family. What blueberry really need is an acidic soil with a PH between 4.5-5.5 for optimal growth, plus they like moist and should only be watered using rain water as the tap water could be way to alkaline. Your 551 should provide the low PH required and a good drainage. You can use your blueberry food you used last year I don't see why you should change it since you switched to a 551 mix.

Containers error on using less. In ground you can just follow the directions. That is usually three applications of CRF starting a little before your last frost date. I do that and still use ammonium sulfate if growth isn't as vigorous and/or green enough. Do a google search for growing blueberries in your country to get better recommendations. You may need to adjust based on your local climate and soil.