Expiration of Fertilizer
I found a box of Ortho blood meal in my garden shed. It has been there at least 10 years. Is it good to use or should I dispose of it? What would I use it on? Also, I have wisteria "tree." It used to be big and lush but since I pruned it, growth has been minimal. In addition, it has bloomed 1 or 2 times in many years. I live in the mountains at 4,500'. What could I do to get some blooms? One more question about Iris. My Iris was separated and replanted 2 years ago. I get very few blooms. What causes bloom failure?
Certified GKH Gardening Expert
First of all, many fertilizers do not come with an expiration date, so this can make it diffcult to know how long it will keep. Generally, its effectiveness will depend on what the product is made of (i.e. liquid, powder, granules, etc.), whether it's derived from organic compounds or chemicals, and how it has been stored. Since blood meal is organic and if it's been kept dry, it should still be ok to use on the plants. Now as to how effective it will be, I do not know, but it will not harm the plants. As for the non-blooming of wisteria and iris plants, you may need more phosphorus in the soil, of which bone meal can help.