I use a few types of fertiliser for my roses and garden plants, to suit various situation.
The most common ones that I use is chicken manure (organic fertiliser), which is also the most economical ones. I would apply it every 2 weeks at my roses.
As I feed the plants I will observe the condition of the soil. I look for traces of earth worms, as this is the best indicator of healthy soil. I will also check the soil texture because the soil texture can give you some indication of amount decomposed matter contained in the soil. And when watering I look for bubbles because this indicates that the soil is well aerated and also good indication that the worms are actively working (tunnelling) beneath the soil.
Another good indicator is after you feed the soil, the organic fertiliser tend to decompose rather quicker if your soil is riched with earth worms.
If these signs are not present, the soil should look either dry and coarse or the other extreme would be wet and muddy. The plant may look sluggish and growth seemed stunted. In this situation, I will change my feeding pattern. I will use water soluble type.
The reason I revert to water soluble is because this would be the most effective short term remedy to restore the plant. The water soluble type will directly feed into the plants' roots thus gives you ample time to rectify the soil condition. I would use N20-P20-K20 and one that will not "burn" the roots.
For dry and coarse soil, I would water it with water soluble fertiliser more frequently. One teaspoon per 4 litre of water. I will feed probably 2 to 3 times a week.
If the soil is wet and muddy, usually this happens after days of consecutive heavy rain, I would daily fork the soil to ensure proper drainage. And monitor the soil condition for a week or two, if no improvement I will replaced the soil with increased mixture of charcoal granule. The purpose of mixing charcoal is to improve the water drainage. It is important that the soil is well aerated and right amount of moist, otherwise the leaves will turn yellow and spotted. This is sign of over watering.
While carrying out these contingencies, I will feed the soil with organic manure and add some earth worms to cultivate vermicomposting that naturally converts organic matter into useful nutrients for the plants. Check the table.
While it would take some time for the organic manure to decompose, I will continue to use water soluble fertilizer until the rose plant grow some new shoots and more healthy leaves. This is clear sign that the rose plant is restored and growing healthily. As the soil gradually improves, I will gradually reduce the frequency of the water soluble type and revert to vermicomposting process to feed the rose plant.
I won't say what I suggested will surely guarantee results but it would definitely increased the chances of success.
If I want to get some extra blooms, I will use fertiliser formulated for flowering. The most common combination is 18N-24P-18K and will use water soluble type to avoid burning the roots. It is not good to use this too frequently, as it would "exhaust" the plants, especially young ones. It is fine to apply on healthy rose plants with bushy leaves and healthy stems.
Read continuation in Part 2