The four types of feeding products for your giant pumpkin

Unlocking Green Secrets: What Fertilizer to Use in the Patch

I share some select product recommendations and this page contains affiliate links. If you take action (click on the link and purchase the product), I will earn some loose change. I hope you take advantage of my recommendations. You do not pay a higher price. – Jeffrey McLain

to know what fertilizer to use in your garden? What about your giant pumpkin patch? I am going to share some of the amendments I use in my giant pumpkin patch. These include fertilizers and other types of amendments that can be used in any vegetable garden. I am not going to give you recommendations on synthetic fertilizers that can be purchased at Home Depot or Lowes.

There are hundreds of products sold for growing pumpkins and the decision of what to use can be extremely challenging. To make it even more difficult, different mixes of fertilizer contain several categories of feeding products, and new products come to market continually. In order to simplify things, I separate feeding products into fertilizers, biofertlizers, and fungicides. Note this is my own way of separating these feeding products based on my observations of store categories. I will describe these categories below with some typical products.

Organic Fertilizer Thoughts

Unlocking Green Secrets: What Fertilizer to Use in the Patch
Where manure is made. Photo by Oriol Pascual.

The is the big kahuna. Fertilizers contain macronutrients that are needed by plants in large quantities, and micronutrient that are needed in smaller amounts. Macronutrients include nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.

The micronutrients include boron, chlorine, copper, iron, manganese, zinc, molybdenum, and nickel. Add carbon, hydrogen, and oxygen which make up most of the plant, and you have a total of 17 elements. That is all of them. Isn’t it surprising that there are a total of 17? One would think there was hundreds of them.

Organic fertilizers popular to the giant pumpkin grower include manure, seaweed or kelp, fish products, cottonseed meal, blood meal, bone meal, etc. Once can construct their own organic fertilizers from common ingredients. For example, cottonseed meal, blood meal, bone meal, and kelp meal can be combined with some dolomitic or calcite limestone to produce a nice natural fertilizer.

If you are in the market for chemical fertilizers, the sky is the limit. These are sold as dry or liquid and the nitrogen, phosphorous, and potassium amounts are listed on the product label (for example, it will say “15-15-15”). In addition, many of these mixes have other macro and micro nutrients included in them. Follow the directions on the label when applying these fertilizers.

My bread and butter in the fertilizer category is cow manure. I get it from a local dairy. Note this manure is often not considered “organic”; however, it is at least natural! I apply a lot of cow manure every year. Sometimes I will mix it in with chicken manure.

While fertilizers are the bread and butter of giant pumpkin growing, it is not the only thing one needs to grow a giant pumpkin. These elements need to be made available to the plant through a variety of means. Biofertilizers and soil enhancers are used to allow the efficient uptake of these nutrients.


I use the term biofertilizers to denote products containing microbials to help with plant growth. Plants use microbial organisms to assist with their feeding. One such common microbial is mycorrhizal fungi which forms a symbiotic relationship with plants in the root zone. These microbials will help the plant with growth, nutrient uptake, stress tolerance, and disease resistance.

A popular biofertilizer is Mammoth Organic Fertilizer Microbial Inoculant. Yes, what a mouthful! It has natural beneficial soil bacteria and microorganisms to free up phosphorus and plant nutrients. The result is better efficiency of your fertilizers (in my case it is my manure). It can be applied through drip or mixed with water and applied as a drench.

The first biofertilizer I will recommend is Bio-Live by Down to Earth. This is a rich, organic fertilizer mix infused with beneficial bacteria and mycorrhizal fungi to stimulate rooting, vigor and optimum plant development. Because of the infusion of bacteria and fungi, I categorize this as a biofertilizer. I purchase this in 50 pound bags and follow the directions on the bag.

I feel great using Bio-Live as I feed the soil with beneficial bacteria and fungi. It encourages root systems, increased yields and superior quality flowers, fruits, herbs and vegetables. Shipping is expensive; however, I find the overall price on Amazon still can’t be beat.

Biofertilizers function as soil enhancers to improve physical, chemical, and biological properties, promoting optimal conditions for plant growth. These enhancers work to enhance soil fertility, structure, and nutrient content. If it sounds to good to be true, that is because it is. Gardeners and giant pumpkin growers have experienced incredible results using soil enhancers.

Another amendment that is very popular in the giant pumpkin growing world is humic and fulvic acid. Humic and fulvic acids are organic compounds found in soil that play important roles in promoting plant growth and soil health. They do things like act as chelators that bind with minerals in the soil, facilitating better nutrient uptake by plant roots. These acids also enhance the permeability of plant cell membranes, improving nutrient absorption and overall plant metabolism.

Additionally, humic and fulvic acid contribute to improved soil structure, water retention, and pH regulation. By stimulating the growth of beneficial soil microorganisms, humic and fulvic acids support nutrient cycling and disease suppression. Their application can enhance a plant’s resistance to environmental stressors, such as drought and salinity, while also promoting seed germination and seedling establishment. There are many humic and fulvic acid products to chose from. My particular choice is BioAg Ful-Humix and BioAg Ful-Power.


Plant fungicides are substances or chemicals designed to control or prevent the growth of fungi on plants. Powdery mildew can become a tremendous problem for pumpkin plants, particularly late in the season. This disease can affect the overall health, growth, and productivity of the pumpkin plants. Fungicides play a crucial role in managing and mitigating these fungal infections. Pumpkin growers also believe these fungicides do more than just protect from the fungus. They appear to improve the structure and health of the pumpkin plants.

A very commonly used product is TKO Phosphite by Grower Solutions. This is a highly concentrated nutrient solution containing mono and di-potassium salts of phosphorus acid. It is very popular and equally expensive. Another product that has similar ingredients but less costly is Reliant Systematic Fungicide.

More information about What Fertilizer to Use

To find more information about pumpkin plant fertilizers, you can explore various reliable sources, both online and offline. You can contact your local agricultural extension office or cooperative extension service, reputable gardening websites and forums where experienced gardeners and experts share insights, websites like the University Extension sites, Gardening Know How, and GardenWeb often provide reliable information on fertilizing pumpkins.

When researching fertilizers, consider factors such as the pumpkin variety, soil composition, and local climate. Always follow recommended application rates and guidelines to avoid over-fertilization, which can be detrimental to plants and the environment. Fertilizer manufacturer websites provide detailed information about their products, including application rates and recommendations for specific crops. Check the websites of reputable fertilizer brands.

Gardening Books and Magazines: Refer to gardening books and magazines that focus on vegetable gardening and specifically pumpkins. These publications often include expert advice on fertilizing, soil preparation, and overall pumpkin care. Be sure to see my book, Backyard Big: Growing Atlantic Giant Pumpkins in your Backyard on Amazon and Barnes & Noble. Be sure to check out my Atlantic Giant Pumpkin Blog for topics as well.

Leave a Comment

Your email address will not be published. Required fields are marked *