Why Do You Need to Fertilize Gardens?

Why do you need to fertilize gardens?

Any garden will run low on nutrients if you continue to grow plants without fertilizing. Plants need a steady supply of nutrients in order to grow and produce flowers and/or fruit.

Plants use nutrients in the soil such as Nitrogen, Phosphorus and Potassium in order to grow, flower and reproduce. Eventually these nutrients will become scarce as the plants use them up, just like water. When plants use up the water in the soil, they will wilt and die unless you provide more water. The same goes for fertilizer. If you don’t maintain a steady supply of fertilizer [nutrients], plants will suffer and die.

Let’s talk about what organic fertilizers do.

Nutrients or Plant Food

Fertilizer provides the 3 main nutrients that support plant life. They are Nitrogen, Phosphorus and Potassium or Potash. These 3 will assure a healthy and productive plant. They are responsible for growth, root development, disease resistance, flowering and fruit production.When the soil runs low on any of these nutrients the plant will suffer and may die. Unless the soil naturally gets organic material deposited on it like fallen leaves, fertilizer will be needed periodically to maintain a healthy garden.

Organic fertilizers like compost and composted manures are slow release long term fertilizers. Non-organic or chemical fertilizers like 5-10-10 are short term fertilizers that dump all of its nutrients quickly.

If you want the absolute best fertilizer, use Worm Castings.

Water Retention

Some soils are good at water retention while others are not. Soils rich in organic material are great at water retention. Clay and sandy soils are not. They tend to dry out or let water run through too quickly.

Clay soils dry, crack and become rock hard. Water does not penetrate well and tends to run off. Once clay gets wet, it does hold on to water but a little too much. Then drainage becomes an issue. Adding compost or any organic material to a clay soil will improve its water retention/drainage characteristics. Organic material helps water penetrate the soil by creating air pockets which allows water to penetrate and drain. I recommend mixing half compost to half clay soil.

Sandy soils are the opposite of clays. Sandy soils do not retain water and drain too quickly. Organic fertilizer will increase water retention and slow down drainage. Plants will have more time to soak up water plus you will have to water less often. A good mixture is 50/50 compost to sandy soil.


Some soils like clay are tightly packed and do not have much space in the matrix. This causes some issues with plant roots. Air has a difficult time penetrating clay soils which is vital for bacteria, microbes and decomposition of any organic material. Aerobic activity in soil is beneficial and needed. Clay soils need organic material mixed in it in order to allow air in. It created gaps and spaces in the soil for water and air.

For proper aeration of tight matrix soils like clay, mix the soil 50/50 with a good organic compost or composted manure.

Enhance Texture

Texture refers to how the soil acts or it’s physical characteristics, for example…is it sandy or compacted or rocky. The proper texture will allow plant roots to grow easily into the soil. A poor texture can restrict root growth and stunt plant growth. Carrots need good soil texture especially but so do all plants. Texture also promotes water retention and aeration.

The perfect texture is soft and moist. When you dig in your garden, your should be able to dig into the soil by hand without difficulty. You shouldn’t need a hammer or screwdriver to dig a small hole. This texture is easily achieved by mixing your soil with compost in a ratio of 50/50 depending on how poor the soil texture is.

Insulate Soil Against Hot and Cold

Organic fertilizers like compost and mulch can insulate the soil from heat or cold if applied on the surface in a 1-2″ layer. Organic material does not absorb heat like soil does from sunlight. Soil heating is responsible for increased water evaporation. If you keep the soil cooler during the day, plants will have more time to take up water. And you will have to water less.

Organic material also can protect the soil and plant roots from the cold. It acts like a thermal blanket during cool nights. It acts as a barrier between the soil and the cold air. Compost is a great thermal regulator. Spread 1-2″ of compost on top of the soil to protect the soil and plant roots from heat or cold.

Soil Drainage

Soil drainage is critical for healthy plants. Most people do not know this and think it’s a bad thing. Why would I want water to drain out? Drainage prevents root rot. If plant roots sit in water for a long period of time, they will rot and the plant will eventually die.

Proper drainage allows water to pass through the soil slowly allowing roots to absorb water before it drains out. Sandy, gravel and organic material are drainage enhancers. Sand and/or gravel are great to place at the bottom of a raised box garden to promote good drainage. Fill the rest of the box garden with a good organic soil or compost. A simpler way to setup a raised box garden is to just fill it with a good organic soil or a 50/50 mix of yard soil and compost. Compost will promote good drainage by itself. The organic material creates spaces and holes in the soil matrix that allow water to pass through.

Attract Beneficial Insects

Believe it or not insects are generally beneficial to gardens and plants in general. Most people believe insects are harmful but most are not. Earth worms are the ultimate but they are not really insects. Worms are very desirable for garden and yards. They help decompose dead plant material, aerate the soil, fertilize the soil with castings and improve the soil texture by borrowing.

Worms are worth their weight in gold when introduced into the soil. Worm castings [worm waste] are the absolute best fertilizer known to man. It’s the perfect food for plants because it’s broken down by the worms’ digestive system in such a way as to be easily absorbed by plant roots. No other fertilizer comes even close. Worm castings also contain beneficial minerals, microbes and bacteria.

Ants can be helpful in the garden too. They will attack some of the harmful insects like aphids, grasshoppers, crickets and white flies.

Ladybugs are welcome in gardens because they eat harmful insects too. Attract them when you can.

Microbes, bacteria and nematodes are also attracted by organic fertilizers like compost and manures. They are beneficial for the soil and plants.They assist with breaking down of dead plant material

What are Non-Organic Fertilizers

Non-organic or chemical fertilizers are man made fertilizers. They are generally composed of Nitrogen, Phosphorus and Potassium. These are 3 vital nutrients for plants. Non-organic fertilizers are label with 3 numbers that describe how much of each nutrient it has. For example 5-10-10 is a non-organic fertilizer with 5% Nitrogen, 10% Phosphorus and 10% Potassium.

Non-organic fertilizers are used when you need nutrients to be available to plants quickly. These chemical fertilizers release the nutrients all at once or very quickly when watered. It can be very useful when you want a quick boost in growth or to save some plants from a deficiency before they die.

What Non-Organic Fertilizers Do

Non-organic or synthetic fertilizers contain Nitrogen, Phosphorus and Potassium in specific percentages or ratios [5-10-10]. They release these 3 nutrients quickly into the soil when watered. These nutrients will provide everything a plant needs to grow, root, maintain a strong immune system, flower and produce fruit.

If the soil is not rich in organic material, synthetic fertilizers can make a garden lush and productive easily. You will need to apply fertilizer periodically to support continued growth and health.

Synthetic fertilizers do nothing for the soil or the soil ecosystem. They only provide vital nutrients for plants.


Organic fertilizers not only provide food for plant grow and health but also enhance/stimulate the entire soil ecosystem. For the healthiest and most productive garden, take care of the entire ecosystem.

Non-organic fertilizers are great for boosting growth or flowering when the soil has deficiencies. It’s inexpensive, easy to apply and works extremely well. It also works fast. You will see results in days unlike organic fertilizers which can take weeks to months for results.