How to Fertilize your Plants
Choosing the best fertilizer for your plants will help your plant stay healthy and grow faster. Fertilizing is critical for houseplants because they are grown in a small amount of soil, where the natural minerals can be depleted quickly. In this article, we will break down the best types of fertilizer, and answer some common fertilizer questions.
Most epiphytes, aroids and other common foliage plants need a 3-1-2 N-P-K ratio.
This means three parts nitrogen - one part phosphorus - and two parts potassium. These three macronutrients contribute to your plant’s leaves, stem, and root health, as well as helping with blooming and maturity.
My personal favourite is MARPHYL® Organic Soil Enhancer. This organic formula contains an abundance of nutrients, vitamins and minerals from the marine phytoplankton, and it’s recommended for use only on household plants, urban/veggies gardens, lawns, golf courses and greenhouses. The best part about it - there is no expiry date! To read more about this product, check out this link here (https://cashmear.ca/products/marphyl)
MACRONUTRIENTS
Plants use macronutrients in large quantities.
Nitrogen (N): helps with leaf growth
Phosphorus (P): helps with harvesting the sun's energy to convert this into growth and reproduction.
Potassium (K): helps with the movement of water, nutrients and carbohydrates in the plant tissue.
For most plants, nitrogen is the most important macronutrient to grow lush foliage plants like Monstera, so it should have the highest number in the ratio.
To find the N-P-K ratio, look for a series of numbers on the fertilizer. Any 3-1-2 ratio fertilizer will have the third number be twice the second number, and the first number be three times the second number. That can be confusing, so here are some examples that all meet the 3-1-2 ratio:
- 3-1-2
- 6-2-3
- 9-3-6
- 12-4-8
- 15-5-10
- 18-6-12
- 21-7-14
Higher numbers mean that the fertilizer is more concentrated, so you need to mix a smaller amount into your water.
Good fertilizers will contain nutrients called micronutrients in addition to these main three. Plants use micronutrients in small quantities.
How to use synthetic fertilizer:
Fertilizer has the potential to damage your plants if you use too much, so make sure to follow the instructions carefully! As long as you use the amount recommended on the bottle or less, it is safe.
Your first time using a fertilizer, start with a smaller amount, and work up to the amount on the instructions over time. Furthermore, start by feeding your plant less regularly, and increase over time if it is doing well.
For liquid fertilizers, mix the correct amount of fertilizer into your water before watering and stir to combine.
For regular feeding with every watering: Mix ¼ – ½ tsp. per gallon of water with every watering
OR For Monthly Feeding: Use 2 – 3 tsp. per gallon of water.
As you can see, you need just a tiny amount of fertilizer for each watering.
Best propagation and organic fertilizer for Monstera
LiquiDirt is an all purpose organic plant food. This fertilizer is sold as a nutritional supplement, but the ingredients do contain nitrogen, phosphorous and potassium, as well as micronutrients and beneficial micro fungi.
I love to use LiquiDirt for everyday watering and especially propagation because it is safe for my pets, has no smell, and impossible to mess up because it cannot burn plants. It helps my Monstera cuttings develop strong root systems faster than growing them with plain water.
How to use propagation and organic fertilizer:
The LiquiDirt comes in a small pouch of powder that lasts a very long time! First, you add water to the pouch to create a super concentrated liquid. Then, you add the concentrated fertilizer a drop at a time to your watering can.
Additionally, add a drop of LiquiDirt concentrate to propagation water once your cuttings start to develop roots.
Best soil additive fertilizer for Monstera
Worm castings, also called vermicompost, is a beneficial fertilizer for Monstera that can be used in lots of ways! Worm castings are small brown granules. The best kind is made from 100% worm droppings and has relatively no smell.
The best part about worm castings for a houseplant parent is that in addition to nutrients and minerals, they also contain beneficial microorganisms. These microorganisms have a symbiotic relationship with plants and protect against root rot caused by harmful fungus and bacteria. Including worm castings in a chunky or rocky soil mix will help the soil fill with good microbes. Even after the initial nutrients are gone, the microbes can break down the organic material in the worm castings to release more.
I include worm castings directly in the soil in my aroid mix. Worm castings can be applied without fear because they cannot burn your plants.
How to use soil additive fertilizer:
Mix worm castings into your soil mixture when potting or repotting your Monstera. In between repots, you can also apply worm castings as a top dressing by spreading a thin layer over the surface of the soil every three months.
Finally, you can make “tea” by steeping worm castings in water overnight before using it to water or spray your plants. Use the tea the next day to take full advantage of the microbes in the worm castings.
Best time to use fertilizer on Monstera
How often to fertilize Monstera
You should fertilize your Monstera if it is actively growing. The frequency of fertilizing will depend on the type of fertilizer.
As a general rule, mild water based fertilizers like Liquidirt and worm casting tea can be applied at every watering. Stronger fertilizers should be applied once every few weeks. Soil additive fertilizers should be applied every few months.
In addition, you may need to change frequency of fertilizing depending on the soil components of your substrate. Plants in soil-less or rock-based mediums (such as those containing perlite, pumice, LECA, and Lechuza-Pon) need more frequent fertilization. These type of mediums do not contain any nutrients as organic matter, and they do not hold nutrients as well as regular soil. As a result, you will need to fertilize more often.
If you are using a soil that already contains fertilizer, such as Miracle-Gro, check the bag to see how long this fertilizer will last. Wait for that length of time to pass before you start adding additional fertilizer.
Should you fertilize Monstera in Winter?
The main differences between summer and winter for plants are the amount of light and the temperature. You control the environment in your home, so that will determine if your plant experiences winter. Just like your watering schedule, your fertilizing schedule should depend on the environment you provide your plants.
If your plant relies on natural light, it will get less light in the winter and slow or stop growth. In this case, you should wait until spring to fertilize. See our Monstera Light requirements
On the other hand, if you use a grow light for your Monstera and it gets the same amount of light year round, it will continue to grow in winter. You can continue to fertilize as normal!
Over and under fertilizing
How to tell if your Monstera needs fertilizer
Signs of a Monstera that needs fertilizer:
- Stunted, slow, or stopped growth
- Discoloration in leaves or yellow areas (this is called chlorosis)
Monstera adansonii commonly display pale new growth with discolored splotches when underfertilized. This is a sign that they do not have enough nutrients to sustain their rapid growth. Monstera deliciosa and the albo variegated varieties grow less quickly, but can also display these issues when they need more food.
What is fertilizer burn?
Fertilizer burn is damage to your plant’s roots caused by too much fertilizer. Once the roots are damaged, the leaves may start to die as well, appearing droopy and crispy.
Here are some common signs of overfertilizing:
- A white crust on top of the soil
- Wilting leaves
- Yellow leaf edges that turn brown
- Stopped or stunted growth
Most of these signs are similar to the symptoms of other types of root damage, such as damage from overwatering which can be confusing.
The best way to treat a Monstera that has too much fertilizer is to rinse the excess out of the soil. You can flush the excess fertilizer out by running water through the plant’s soil until it drains out the bottom, repeating several times if necessary. Make sure the plant has well draining soil or dries thoroughly before the next watering to avoid overwatering. For severe cases where there is too much fertilizer to remove, it is best to repot the plant in soil with no fertilizer. Do this as a last resort because repotting can further damage roots.
Is organic or synthetic fertilizer best for Monstera?
The nutrients in organic (“natural”) and synthetic fertilizer are the exact same chemicals. The reason that synthetic fertilizer has a reputation for harming plants, while organic fertilizer does not, is because it is usually much stronger.
Choose synthetic fertilizer if you:
- Want a stronger fertilizer that will give immediate results and maximum growth
- Are prepared to carefully follow directions to apply it correctly
- Are using a soilless medium to grow your Monstera and it needs more nutrients
Use organic fertilizer if you:
- Are okay with applying a weaker fertilizer more frequently
- Are worried about damaging your plants by overfertilizing, or you have an unhealthy, young, or rooting plant/cutting that needs a weaker fertilizer
- Want to create a healthy microbiome in your soil where microbes break down the organic fertilizer
You can also combine multiple types of fertilizer to get the best effects of all of them! Just make sure to use less of each variety than you normally would.