Ever wondered why sometimes your plants are big and green but don’t blossom or fruit like in the picture. How about why your plants don’t grow as big as they were advertised or maybe every year they come back smaller and smaller. It all has to with soil nutrients; specifically NPK. NPK stands for nitrogen, phosphorous, and potassium. Nitrogen is responsible for plant foliage; specifically the number of and size of leaves on a plant. The bushier the plant, the more nitrogen there is in the soil. This is a problem for blossoming and fruiting plants because the leaves divert all the plant’s energy to feed the leaves, which leaves nothing for the formation of blooms and fruits. Nitrogen is found in high concentrations in charcoal, worm castings and fish. A bit of gardening history: Native Americans use to plant their corns with fish. Now you know why they had so much corn. Phosphorous is mandatory for root and shoot growth. This is needed in higher concentrations when starting plants from seed. It is found in high concentrations in blood meal and bat guano. Potassium on the other hand is responsible for blooms, fruits and overall hardiness such as disease resistance. This should be added in high concentrations when the plant is blooming. High levels of this substance is found in bone aka bone meal, potash and wood ash aka biochar. Note: wood ash (biochar) should not be used on acid loving plants so avoid use on fruits and potatoes and flowers like hydrangeas as it will cause potato scab. Yes…it’s as yucky as it sounds. It’s best to work it into the soil in late fall so that it can be fully activated and incorporated into the soil before planting the next season.
Balanced fertilizers will have equal part ratios such as 7-7-7. Specialized products wills have different ratios. For instance, tomato and strawberry fertilizer will have a 2-2-6 ratio. The 6 for the potassium is to ensure lots of blooms that eventually become fruits. Then there is 15-15-15 that is recommended for potatoes because they are heavy feeders. This is especially true for sweet potatoes as they will run and vine along the ground unlike tradition potatoes.
Doing the Math: Calculating Fertilizer Rates
I am by no means a math genius and anyone who says otherwise has lied to you. I will not attempt to even explain how this is done but here is a link to some YouTube videos of people who can. Good luck and God speed. https://www.youtube.com/results?search_query=calculating+fertilizer+rates
For the most part, I look at the boxes of the individual elements I need and use according to the instructions for the area I am working with but for those who want to or need to mix their own, see the previous link.
My Soil Amendments
I used both charcoal and sand to improve soil drainage. However, charcoal is much moisture expensive but it does absorb impurities. I use whatever is left over from cooking on the grill but fresh is best. Wood chips are used as mulch to conserve water and as a soil medium. Whatever shrubs trimming I put through the wood chipper, I reuse as mulch; often times in the same area. Micronutrients such as Azomite and a water soluble hydroponic fertilizer, bat guano and worm castings are also used. I combine all these things and incorporate them into the soils during preparation prior to planting. When I make a compost tea I use all these things as well as emulsified fish. It stinks but it works like God blessed your garden in person.
And remember; please don’t hesitate to contact me for a list of the brand products I use.