Plants need to eat!


No not hamburgers and fries like us, but they do need more than water and sunlight to grow and prosper. Living in a little pot, your plant is dependent on you for all its meals.


Think of fertilizer as the second part of your soil. New potting soil normally has fertilizer worked into the mix, however after a few months your plant has gobbled up most of what is available and will need you to step in and assist. Knowing a few important facts can mean the difference between an "ok" looking plant or a stunning specimen.


Fertilizer is broken down into 3 marconutrients, nitrogen, phosphorus and potassium known as N-P-K.


The N-P-K ratio is the percentage the product contains by volume of nitrogen (chemical symbol N), phosphorus (P), and potassium (K). A 16-16-16 fertilizer, for example, contains 16% nitrogen, 16% phosphorus, and 16% potassium. A 25-4-2 formulation contains 25% nitrogen, 4% phosphorus, and 2% potassium.


This is especially important to know depending on what you want your plant to do. If you are looking for a super, green plant, you will want to have a higher nitrogen based fertilizer. If you are looking to promote flowers, and maybe fruit, then you will need to use a higher phosphorus based fertilizer.


All fertilizers contain at least one of these components; if any is missing, the ratio will show a zero for that nutrient (a 12-0-0 fertilizer contains nitrogen but no phosphorus or potassium, for instance). Boxed, bagged, and bottled products display the N-P-K ratio on the label.


Nitrogen (N) mainly affects vegetative growth and general health. Chlorophyll, the green substance in plants responsible for photosynthesis, is largely composed of nitrogen. It is also used heavily in new shoots, buds and leaves. Air contains about 78% nitrogen, but atmospheric nitrogen is not readily available to plants. They must absorb it through the soil.

Nitrogen deficiency is recognized by the yellowing of older leaves, slowing or stopping of growth. Leaves may drop sooner than expected. Excess nitrogen is recognized by extremely fast growth, resulting in long, spindly, weak shoots with dark green leaves.


Phosphorus (P) is important for healthy roots and is used more heavily during blooming and seed set. Phosphorus is easily rendered unavailable to plants when the pH is slightly unbalanced. It is released in soil through decomposing organic matter. If you want big, beautiful flowers then you need to pump up the phosphorus.

Phosphorus deficiency is recognized by dull green leaves and purplish stems. The plant is generally unhealthy, sometimes yellowing. Lack of blooming with lush green foliage may also indicated a lack of phosphorus.


If you are wanting to grow big, beautiful and bountiful fruits and vegetables, or an abundance of striking flowers, use a fertilizer heavy on phosphorus.


Potassium (K) is important for general health of plants. It is key in the formation of chlorophyll and other plant compounds. Potassium is also known to help with disease resistance. Its kinda like taking an multi-vitamin everyday to ward off the flu.

Potassium deficiency is hard to symptomize, but plants are generally sickly, with small fruit, yellowing from the older leaves upwards, and sickly blooms.



I use several different types of fertilizers, depending on the time of year, how busy I am and what my plant actually needs.


Liquid Fertilizers are added to your watering can, usually at half the recommended strength

as started on the box for indoor houseplants. Depending on label instructions, you might fertilize every time you water or every other time. The type of plant will also impact this, as some—especially those with dramatic large blooms—may require more frequent feeding. Always study up on the plants to learn about the
specific nutritional needs. Liquid fertilizer provides a steady supply of nutrients that you can precisely control. It's easy to stop feeding when the plant is dormant during the winter months, for example, or step up the feeding when they are sending up new growth. The disadvantage, however, is that you need to remember to do it every time.


I use liquid fertilizers indoors once all my plants move back inside for the winter. This allows me to manage each plant's needs.


Slow Release Fertilizers are super easy. Just sprinkle on and your done. They are time-
release coated shells that slowly leach nutrients into the soil. The individual pellets have coatings of different thicknesses that dissolve at different rates, so the actual release of the fertilizer is staggered over time. A single application can last between four and ninth months. The main drawback is you have no true control over the fertilizer, but it delivers food even when you forget!


I use slow release fertilizers in the spring when I move my plants out doors for their summer vacation. Its simple to sprinkle on a dose and let them grow.


As a word of warning
—always follow the label instructions on your fertilizer. Too much fertilizer can kill a plant or scorch its leaves. Too much fertilizer is often worse than not enough, yet overfeeding is one of the most common mistakes made by well-meaning houseplant hobbyist.