“I understand potted plants need to be fertilized more often than plants in the ground. Is that true? Also how much and how often should I use worm tea in my potted plants {tomatoes}? And can I over worm tea? Thank you for your help.” ~ Chris Vialpando
Hi Chris,
Different plants have different needs, and an obvious rule of thumb is that the faster a plant grows then the more frequent it needs to fertilized!
You are correct that in some cases potted plants will need fertilization more than outdoor garden plants.
In fact there are many plants that can take care of themselves outdoors with out the need of help i.e. if you left your garden unattended, sure you will get an unsightly garden, but many plants can take care of themselves and grow well.
We will talk about three things:
1. The nutrients source
2. Watering
3. Nutrient retention
Depending on your soil, garden plants obtain nutrients from natural organic matter around them. Fallen tree leaves, natural worm casts, fallen fruits, dead animals and organisms etc. With the help of micro-organisms these are broken down into suitable nutrients for the plants.
For an indoor potted plant, natural sources of nutrients are lacking.
Basically whatever is in the pot stays in the pot and until something is added there will be no increase in nutritional value. As the plant grows the nutrition will be used to grow the plant itself, so after time it will get depleted. Therefore to boost up nutrition, you will need to add fertilizers.
The way the plants are watered also contributes to the reason why potted plants need more fertilizing. Usually garden plants are watered by rain, and in a hot summers day by you spending time out watering the garden. The water is seeped in to the soil and stays in the soil until it is used by the plants or evaporated away.
For potted plants, the need for watering is a lot more frequent.
The small pot creates a limit in the amount of water it can hold and the soil inside dries up more quickly. The extra thing is when these plants are watered they are usually over watered. This causes a lot of the nutrition being washed out of the soil into the collection plate at the bottom. So the more you water the more nutrition you are washing out of the potted soil.
The washing of nutrients is only true for chemical fertilizers, where the nutrients are already in an available form.
These are easily dissolvable in water which gets washed out really easily, creating a low nutrient retention. This is why slow releasing fertilizers are especially of good use for potted plants. These will not be washed away easily by water, but instead release the nutrients as time goes by.
This leads us to good news about worms casts!
Since I have mentioned in my previous post that wormcast is a slow releasing fertilizer! Much of the nutrients are locked in an organic form which is slowly release and converted by the microbes in the soil.
In regards to worm tea, you will need to be careful which type you are talking about.
The worm tea which is brewed with oxygen and a food source is the proper type. This can be used as much as you want on the plants (of course what I mean is as much as you would water it! Don’t start drowning them!) Brewed worm tea is full of micro-organisms which helps build up the plants immune system and helps structure the soil and the nutrients within it. This will be especially effective when used with worm casts.
If the worm tea you are talking about is the liquid from the bottom of your wormery, this is better known as worm leachate.
Leachate is different to worm tea in that there isn’t much microbial life in it, but will have some organic matter. There can be a lot of salt content (depending on the feed) and if it has gone anaerobic and produces an odor, it will harm your plant!
However the organic matter it contains will provide a good slow releasing fertilizing effect for your potted plants.
Worm leachate needs to be diluted for use.
You can use it to water your plants, but again don’t drench it. As long as you dilute it at least 10:1, use it as much as you would water your plant. If in doubt about the smell then don’t use it!
