QuestionI use a drip system to water my roses. I like to feed my roses with granular fertilizer which I spread around the base of the roses and mix into the soil just so the fertilizer is covered. If I have only one water emitter for each rose and the water flow is only enough to wet a little area on the surface before soaking downward, how can the remaining fertilizer surrounding the plant get watered to be taken to the roots? I have no problem when I use a hose to water because I fill up the basin, which contains the fertilizer, around the rose. I love the drip system, but feeding with the drip system is where is where my question lies.
AnswerIf you put some granular fertilizer in a bucket of water, you would see that it does dissolve very quickly. Your method of hosing it is a good idea, as that will dissolve it quicker that the drip system. Usually, dry fertilizer is pushed down by the rain. However liquid is really a better way to go if you always water by the drip system. I am assuming that the drip is 1 gallon per minute. Of course fertilizing through your system saves a lot of time and effort but be careful what you choose as some will clog up the drippers. Miracle Gro apparently works if you first use hot water to melt it down and then add to the drip system. It works best through the drip type, if you cut the amount down and just let is go through whenever you water.There are also specific types of fertilizers made especially for drip type irrigation. I use a drip watering set up but have never had the courage to use fertilizer in it because flushing it out in the fall to make sure it is free of any left over fertilizers, is a lot of work.You also have to have a backflow valve to make sure the fertilizer doesn't get into your drinking water or well water. What often happens with a drip is that the water stays in a confined circle at the base of the roses. As you probably know, there are different heads for the drip and one of them is downward sprinkle which only water where you want it too. Also there are different rates of injection flow for different systems. I use wood mulch every spring but before I put it on I sprinkle the fertilizer around the base. Then I really water it in, finally the mulch goes over it. Then around July I use liquid fish or Alfalfa, and so far this has worked for me. I am seriously think of changing the emitters to 2 gallons a minute because I have sandy soil so I always water at night to make sure I get all the water and it doesn't evaporate. I have been told that not all plants will get the exact same amount of nutrients. It is stronger at the beginning and then weakens with every gallon of water.As I have some frailer roses that need more, it isn't a good idea for me. I honestly feel that if you are really sloshing the water at the time you fertilize and very hot weather when I would use the drip during the night, then what you are doing is fine.