How to Make Your Own Tomato Fertilizer

Nothing tastes as good as freshly picked homegrown tomatoes. But to get the most out of your plants they require fertilizing. Notoriously heavy feeding plants, tomatoes require regular doses of fertilizer throughout the growing season for a truly bumper crop of flavor filled fruit to form.

Trying to find a good tomato fertilizer that is completely safe to use on your garden can be difficult. However, there is a solution. Making your own tomato fertilizer is surprisingly easy. It is also guaranteed to contain only beneficial organic matter, making it completely safe to use on both outdoor and indoor plants. A further benefit of making your own tomato fertilizer is that pretty much all the ingredients are already in your home, just waiting to be used.

1 Make your own tomato fertilizer
Making your own plant food is an easy way to ensure that your growing plants get all the nutrients that they need. 

Like knowing how to ripen green tomatoes, fertilizing your plants is a key part of growing your own tomatoes. If you want to make your own tomato fertilizer to boost your plants this article will take you through everything that you need to know.

What Nutrients do Tomatoes Need?

Before we start looking at how to make a tomato fertilizer, we shall first examine what nutrients your plants require and why.

The two main nutrients growing tomato plants need are phosphorus and calcium.

Phosphorus bolsters healthy growth. Playing a key role in respiration, protein synthesis and photosynthesis, phosphorus also takes water to the cells of developing fruit. In other words a regular dose of phosphorus encourages healthy plants, robust root systems, large flowers and fruit to form.

Calcium helps to prevent issues such as blossom end rot. This is an unsightly condition that causes sunken holes to appear in the fruit. Calcium also helps cells to develop and function. Finally, calcium plays a key role in pollen germination.

Growing tomatoes also require a little nitrogen. This helps healthy, strong vines to develop. It also encourages healthy, green foliage to form. But you must be careful not to give your plants too much nitrogen. Overdosing on nitrogen encourages too much foliage to form at the expense of flower and fruit production.

2 Balanced fertilizers promote growth
A balanced fertilizer promotes healthy growth and fruit production.

Another key nutrient is potassium. This helps to bolster fruit yield. It also ensures the fruit is of a good quality.

Tomatoes also require some sulfur, magnesium and a range of micronutrients.

Now that you know what your plants require, you can start compiling the ingredients you need to make your own tomato fertilizer.

What Do I Need?

To make your own tomato fertilizer, you will need:

  • A large bucket or container. A 1 Gallon Black All Plastic Bucket is ideal. Not only is it large enough but it also comes with a lid to ensure that your mixture isn’t contaminated.
  • A wooden stick or stake to stir your mixture with
  • Half a gallon of compost. A rich homemade compost is ideal. You can also purchase fresh compost. Basically, the better the quality of your compost the better the fertilizer. Alternatively a blend of animal compost and coconut coir is ideal.
  • Half a cup of pet fur or human hair. This contains the protein keratin. It also contains good amounts of nitrogen sulfate and small traces of other minerals. Hair makes a great slow release plant food because it takes time to break down. Cut the hair or fur into small pieces. Cat, dog, guinea pig and ferret hair are all ideal.
  • 1 cup of crushed egg shells. Rich in calcium, ensure that the shells are completely dry before crushing them into small pieces. You can help the shells to dry out by baking them in the oven for a few minutes.
  • 1 cup of used tea or coffee grounds, these are rich in phosphorus, potassium and low amounts of nitrogen. Before using ensure that the grounds are fully dried out. You can speed up the drying out process be spreading the grounds on a baking tray and placing in the oven for a few minutes
  • 1 cup of wood ashes, there are another great source of potassium and trace minerals

3 Some ingredients cut household waste
Like eggshells, all the ingredients you need are already in your home or easy to source. Making your own plant food is a great way to reduce your household waste. 

You can also add:

  • 2 cups of dried alfalfa leaves or alfalfa pellets. Alfalfa contains a growth hormone which is commonly used on roses to promote flowers and healthy growth. It has the same benefits for tomato plants. Pet and feed stores typically sell alfalfa pellets as rabbit food, just make sure it is completely alfalfa and not a mix of other products.
  • 2 cups of rabbit droppings. Rich in organic matter as well as nitrogen and phosphorus, this is one of the best animal manures you can use. While it is rich in nutrients, it is not so rich that it will burn plants.
  • Vermicompost

How to Make Your Tomato Fertilizer

Once you have assembled your ingredients, it is time to start making your tomato fertilizer. While it may sound complicated this is actually quite a straightforward process. This means that you can make your plant food quickly and easily.

Put the half gallon of compost into your bucket or container. Give it a quick stir to break up any large clumps.

Stir in the hair and, if you are using, rabbit droppings. Make sure they are well incorporated. Continue to stir the mixture until it is clump free.

Next add the other ingredients: the eggshells, coffee grounds, wood ash and, if you are using them, the alfalfa leaves or pellets. Add the ingredients slowly, one at a time, stirring well so that they are all fully incorporated.

After working in all the ingredients your tomato fertilizer is ready to use.

How to Use Your Fertilizer

Your homemade tomato fertilizer can be used in a number of different ways.

When planting out your toms, you can use your mixture to refill the hole. Make sure that you water the mixture in well after filling the hole. This helps the nutrients contained in the mixture quickly reach the roots.

You can also apply a further dose of homemade tomato fertilizer a few months after planting as a side dressing. Again, make sure that you water the mixture in well.

4 Begin fertilizing after planting
Begin fertilizing immediately after transplanting to support robust, healthy growth. 

You can also turn your tomato fertilizer into a liquid plant food.

Converting into a Liquid Solution

Similar to a compost tea, you can easily convert your homemade plant food into a liquid solution that can be incorporated into your watering routing.

Mix one pound of homemade fertilizer in a gallon and half of water. Stir the mixture in well.

After stirring, cover the mixture with a lid and place in a temperature neutral position, away from extremes of heat and cold. Return to your mixture a couple of times a day and give it a good stir. Continue to do this for a few days.

After allowing the solution to steep for a few days, strain it. This liquid can then be applied undiluted or diluted to half its strength in a watering can. After straining, the solid parts of the fertilizer can be returned to a compost pile or sprinkled around the base of your garden plants.

In liquid form, a dose of homemade tomato fertilizer can be applied once a week to your plants.

Other Natural Fertilizers

As well as making your own plant food there are a number of other natural fertilizers you can apply to bolster the growth of your tomato plants.

Rich compost is a great way to add nutrients to your plants and soil. A compost bin is easy to establish and a great way to recycle waste. As well as containing lots of nutrients compost also slowly breaks down, gradually releasing them into the soil for a long lasting nutritional boost.

5 Start a compost bin
A compost bin helps to reduce your household waste. It can also benefit your garden.

Epsom Salts are a great source of magnesium, helping to produce stronger, richer plants and heavier, tastier fruit. It can also help to prevent blossom end rot. This is a great guide to using Epsom Salts on your tomatoes.

Fish Emulsion is another natural, nutritious plant food. It can be applied when planting and during the growing season and is also suitable for use on indoor plants. Rich in phosphorus, potassium and nitrogen as well as magnesium, sulfur, and calcium, this is a great, all round plant food. Unlike compost, fish emulsion gives plants an immediate boost. You can also apply fish emulsion as a foliar spray.


Similarly, seaweed has a lot of trace elements that help with fruit formation.

Organic Cottonseed Meal is rich in nitrogen, phosphorus and potassium making it particularly beneficial during the early stages of plant growth. This is a slow release fertilizer that also contains trace elements such as sulfur, magnesium, calcium and zinc. Make sure you use an organic product, others can contain residual traces of pesticides.

Animal manure is another classic way to boost your plants. Don’t use cat or dog manure, these can be highly toxic to humans and are full of pathogens. Instead, use manure from vegetarian animals such as horses or cattle. Avoid chicken manure. The manure must be aged or composted before applying. It is best used around transplanted seedlings.

Other Ways to Naturally Boost Your Plants

As well as regularly fertilizing them, there are a number of other, simple things that you can do to boost your plants.

Firstly, prepare the beds or soil properly before planting. Enrich the beds by working in composted cow or chicken manure. You can also purchase or make your own worm castings with a vermicomposter. Vermicompost is full of nutrients and microorganisms that help to keep soil borne pests away.

Before transplanting take the time to properly harden off your plants. You should also avoid transplanting on hot or windy days. Pinch out the lower two or three leaf sets before planting. Remember to space the plants out correctly when transplanting. This helps to encourage air to circulate around the plants.

Prior to planting, use a soil test kit to check the health of your soil. You can then use this information to make any necessary amendments before transplanting.

Fertilize your plants after transplanting and again a few weeks later when the plants are established and new growth is visible. Continue to fertilize regularly throughout the growing season. You can also give the plants a supplemental boost of plant food or fish emulsion when fruit starts to form. Don’t be afraid to add a little more fertilizer to your plants if they begin to look a little tired or growth and production begins to slow.

Caring for plants correctly, watering well, providing support and pruning if necessary all helps to promote robust growth and healthy plants. Companion plants such as marigolds can also be used to help plants thrive.

6 Tomato fertilizer keeps plants healthy
Regularly fertilizing your plants helps them to remain healthy and productive.

A necessary part of growing your own tomatoes, a  tomato fertilizer helps to promote healthy growth and fruit production. It is also surprisingly easy to make an effective, chemical free tomato fertilizer at home.

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