Fertilizing your roses regularly gives them the additional boost to grow stronger and faster. Getting some good rose gardening advice on how to fertilize is the first step to growing vigorous and healthy roses. There are two types of fertilizers: organic and synthetic. Synthetic fertilizers are nitrate based and organic fertilizers are nitrite-based. Nitrite-based fertilizers can only be broken down with microbial activity. The easiest way to understand the difference is that organic fertilizers feed the soil, which in turn feeds the plant while synthetic fertilizers directly feed the plant.
All fertilizers are composed of three natural elements: nitrogen, phosphorus, and potassium, and a few minor elements like magnesium and calcium, and several trace elements like iron, manganese, boron, etc. Nitrogen primarily helps your roses grow stronger canes and greener foliage. Phosphorus assists in growth of blooms and rose hips. Potassium concentrates on developing the roots and stems. Brown or purpled edged leaves manifest a lack of potassium and yellowed leaves could mean either excess calcium or lack of iron.
Some examples of organic fertilizers are crab meal, bone meal, blood meal, alfalfa, canola, and fish pellets, green sand, and kelp. Anything derived from deceased animal or plant matter forms organic fertilizers.
Always read and use according to the labels on the fertilizer bags. Incorrect use of fertilizers can cause severe damage to your roses. If the growth tips get too much nitrogen, they will attract plant-sucking pests like aphids.
Fertilizing your roses while planting, in the spring, and in summer. All fertilizing must cease at least six weeks prior to the onset of frost. When you plant your roses, check the soil and if magnesium levels are low, add some Epsom salts. A slightly acidic potting soil (pH 6.5) with addition of some alfalfa or canola pellets and bone meal is ideal for your roses.
Fertilize for about two weeks in spring after your plants start giving out new leaves. At the base of the plant, dig lightly for about 12 inches around the plant using a garden fork and then sprinkle or spray the fertilizer and cover with soil. Moist fertilized soil gives maximum benefit to the roots.
In summer, you could spray a liquid fertilizer every two weeks but remember to follow the instructions carefully. Avoid spraying on leaves when the temperature is high as it could cause leaf burn.
You can choose from several fertilizing devices depending on the size of your rose garden. If you have just 5 to 10 rose plants, you could easily sprinkle with your hand, or mix water-soluble fertilizers in a bucket of water and carry it around the garden, or use a hose-end sprayer. For about 50 roses, you could probably manage with a siphoning device that attaches a faucet to your tube, which is immersed in a bucket of fertilizer. But, this device clogs frequently and has to be cleaned thoroughly after every use and you can never be sure if it is delivering the right quantity of fertilizer to your roses.
Increasingly, experienced rose gardeners prefer organic fertilizers as they are long lasting and improve the soil gradually by slowly releasing nutrients into the soil even as they break down. This keeps roses well fed throughout the season and able to resist diseases and tolerate extreme weather conditions.