When Do I Fertilize My Plants?
First you have to determine if you need to fertilize. What are your plant’s basic needs and what nutrients are available to your plant already? Read this post on Soils and Soilless Media to understand the importance of the plant’s growing medium to the availability of a nutrient to the plant.
- Soilless media require fertilizer because they do not contain any inherent nutrients, except what is added.
- Soil contains a supply of nutrients in varying amounts.
Not all deficiencies are because the nutrient isn’t available, it may be that the plant can’t access it due to the soil’s pH, salinity, lack of organic matter, or leaching due to too much rainfall or over watering.
I know I stress it, but it’s important. Know your plant’s basic needs. It doesn’t help your plant to over fertilize. While it is important not to over fertilize, it is important to ensure a steady supply of the needed nutrients. Waiting until your plants exhibit signs of a deficiency is also not advised. Perform a soil test to determine the nutrient and pH levels.
Deficiencies
If plants do not have enough of a nutrient, they exhibit a symptom that tells you what is wrong.
There are several signs of deficiencies and it is important to recognize them when they are happening because the sooner you correct them, the less stressed your plant will be. Keep in mind that some symptoms may be due to pest damage or disease, rather than a nutrient deficiency. Read about The 5 Steps of IPM and identifying the problem.
Symptoms
Growth
- Plants won’t be as vigorous and may be stunted
- Leaves may be distorted / twisted
- Leaves may be burnt, wilt
- Plant may deform
Colour
- Chlorosis or yellowing of leaves
- Interveinal Chlorosis – the margins of the leaf yellow and the veins remain green
- Purplish-red colouring of leaves
Dying
- Necrosis – death of the plant or parts of the plant
