Apples and oranges.....you cannot compare the two products at all, especially in terms of analysis. If you are determined to use the Roots stuff, then you need to follow the instructions on that label, period. Are you growing in the ground or in containers?

The elements N-P-K come from different sources and cannot be compared with each other in terms of getting one to deliver the same as the other.

I will contact the company tomorrow. I've got the dahlias in the ground. Thanks for your thoughts.

I think you are asking the wrong question. 5-10-10 is really a ratio. That's what's important, not the actual numbers themselves because by applying per the directions you are delivering the proper amount to the plant.

5-10-10 means that for every part of Nitrogen, you are also delivering two parts each of Phosphorus and Potassium.

The Roots Organic at 0.5-2-1.5 isn't that ratio. For every one part of Nitrogen, it is also adding four parts of Phosphorus and three parts of Potassium. Depending on how much you feed you will either be underfeeding Nitrogen or overfeeding Phosphorus/Potassium. It is the wrong fertilizer formulation.

You want a fertilizer where the N is one half of the value of the P and the K, and then feed according directions. It can be 5-10-10 or 2.5-5-5 or 1-2-2 or 10-20-20. It's the relationships between the numbers that is key, because you can always dilute or concentrate depending on how often you are feeding.

Rhizo sorry I forgot to get back to you, the dahlias are in the ground.

Richard, thank you for your statement of wanting P and K twice the amount of N, that statement makes sense to m.

I haven't been able to find that ratio in an organic product. Dr Earth Rose food is 4-6-2, Epsoma Tomato food is 3-4-6. I have looked at several other organic brands and none of them are 1-2-2 ratio.

I know it may not matter very much but I'd like to follow the recommendation I've read many times over the years of using a "rose food, such as 5-10-10," but with an organic product. I will say that the recommendation of 5-10-10 was most likely from years ago when using organic products wasn't so popular.

I'm driving myself nuts as you can see, sorry.

Thanks again,

Ginny

" I haven't been able to find that ratio in an organic product. Dr Earth Rose food is 4-6-2, Epsoma Tomato food is 3-4-6. "

Organic fertilizers are just combinations of organic ingredients like seed meal, blood meal. chicken manure, bone meal, and such. You can start with something that is close, and then boost the lowest element with another amendment. For example, you could use the Epsoma Tomato fertilizer and then add some Espoma Triple Phosphate or Bone Meal.

The other thing to be aware of is that with organics the amendment has to break down in the soil before it is available to plants, and different substances break down at different rates. Ideally you want the nutrients to be delivered to the plant at the same time.