For years I gardened without a single thought about fertilizers, how to use them properly, what kinds to use, etc. My garden also suffered in those years due to my lack of knowledge. We live and we learn.
Sometimes our soil is blessed. Sometimes, it may need sunshine, rain, and a little weeding. Other times we face issues of nutrient-depleted soils, poor potting soils, compost lacking certain nutrients, etc. In these cases, it is important to be able to identify what a plant or the soil may need to help the plant thrive. NPK or Nitrogen, Phosphorous, and Potassium are macronutrients all plants need. You’ll notice that there are 3 sets of numbers separated by dashes on the back of any fertilizer packaging. These numbers represent the percentage of macronutrients in weight. The remaining percentage in weight of the fertilizer is typically fillers or micronutrients or a combination of both.
Plants need these 3 essential nutrients, NPK for many reasons. Nitrogen- to help give the plant the energy it needs to grow to support fruits or vegetables through photosynthesis. Phosphorus- to help the plant establish a healthy root system to uptake nutrients required. It helps the plant store and transfers the energy it needs from photosynthesis. Potassium- Is the activator of enzymes that initiate all the plant's processes. Potassium activates more than 60 different processes involved in plant growth. It also increases yields.
Below I have compiled a list of fertilizers I have been using for several years now and have had success with. I prefer organic fertilizers over anything. Nothing has worked as great as these organic fertilizers for me, other than the FPJ I make myself. The disadvantage of the FPJ is there is no set or free way to test it’s NPK ratios. It is effective for growth/healthy plants, but I need to further test it during the plants blooming phase, which I will be doing very soon in the experiment garden.
For a Nitrogen source, I currently fertilize with the FPJ. In the past, I have used Espoma 3 lbs Blood Meal Organic Fertilizer. It’s an excellent source of organic Nitrogen.
While I start seeds indoors, I used to apply blood meal to the soil outdoors while amending the soil in the garden yearly. It helps restore any depleted nitrogen from soil from the previous crops. Another great source is aged manure. Something I use now when preparing my garden plots is adding rabbit manure. It doesn't have to be composted and aged. I then add several inches of compost.
A creator I saw on TikTok by the user name @Mileviewacres recently suggested adding Alfalfa Pellets to the soil while prepping it in the spring for a nitrogen source. This is truly an amazing idea. You can usually find a bag in a feed store for horses. I saw them recently priced for $17 for a 40lb bag. Another method many people use is cover crops. We all know beans add nitrogen to your soil. Growing beans as a cover crop is a great idea too.
Right after my seedlings develop a second set of leaves I start them on a fertilizer that's high in nitrogen. I would typically apply it when I am transplanting my plants from peat pellets to 4" pots. I would add the blood meal according to the directions to my soil as I transplanted the plants.
Most of us add nitrogen to our soil while prepping our gardens in the spring, while we transplant, and when our plants show signs of having a deficiency. A few signs of your plant needing a nitrogen boost are:
Yellowing of leaves when overwatering isn't an issue
very light green to lime green leaves & they are getting plenty of sun/light
Stunted or no growth
once they have established a 2nd set of leaves
All-Purpose Organic Vegetable Fertilizer
Once it is warm enough and I transplant my plants to the garden I swap my fertilizer for something a little more suited for their life stage. By this time most of my plants like tomatoes are right at about 6-8 weeks old. I prefer to use an organic fertilizer more catered to the plants I am growing like vegetables.
This organic fertilizer has an NPK
ratio of 2-5-3. 2% Nitrogen, 5% Phosphorus, 3% Potassium. I apply this to the soil when I transplant my vegetables like tomatoes to
the garden. I use the amount recommended on the packaging in the hole I dig to plant in. I mix it well with soil dug from the hole. I then transplant my plant and water at the base. I apply this every 3/4 weeks to the top of the soil, depending on how much
rain we receive during that time.
Once my plants have been in the garden for several weeks and I know they will be set to harvest soon, or have started to bloom I swap my fertilizer once again to something higher in phosphorous and potassium. Keep in mind, all these fertilizers serve a purpose at different times of the year in my garden. I used to buy nothing but all-purpose fertilizers and fertilized accordingly. I found that I ended up with too much of one nutrient and not enough of another. Having these different fertilizers on hand at all times has truly saved my garden in a pinch. Some signs you made need to give your plants a phosphorus boost:
Purpling in the leaves, especially tomatoes. Sometimes can look dark blue to even red.
When plants start to bloom
Every spring while prepping my garden I always add bone meal to the soil. Bone meal is high in phosphorous and it is an organic source. I also add bone meal to the soil when I transplant my plants from peat pellets to 4" pots a few weeks before they go out to the garden And again a few weeks before harvest. Another source of phosphorous I add is hardwood ash from my fire pit to my compost pile while it is actively decomposing.
This bone meal is an excellent source of phosphorus. I have always purchased the powder form. I find it more effective for large areas like my in-ground garden.
If you grow more potted plants
you may love their bone meal spike option. I am even considering using them my self for my winter garden inside the home this year.
When my plants show their first signs of blooms I start making banana water. I keep this handy for use while watering my blooming plants. Giving them a potassium boost increases your yields. Today while doing my morning garden stroll I discovered two tomato plants with mega blooms from watering them with banana water recently. Mega blooms lead to mega tomatoes in my experience. The last time I experienced mega blooms I grew a 2lb tomato.
Signs your plant may need a potassium boost:
When they start to bloom
brown or wilted leaves
Stunted/ slow growth
There are no set measurements I use when making or using banana water. I typically shove 3-5 peels in a half-gallon jar. Then I use 1/4 of that 1/2 gallon in my watering pale.
Gather banana peels and place them in a glass jar.
Fill with water and leave a little bit of headspace for gas from fermenting.
Place lid loosely on top to allow gases to pass through.
Let the mixture sit for 3-7 days.
Strain, and mix with water (preferably rainwater) when watering plants weekly while in bloom.