Using leftover pumpkin as fertilizer –expert tips

Everything you need to know about using leftover pumpkin as fertilizer

Pumpkins in a garden
(Image credit: Helen Sessions / Alamy Stock Photo)

Is using pumpkins as fertilizer in your garden a good idea? If you've gone all out on decorating with pumpkins this fall, you may be wondering what you'll be doing with all those pumpkins once the festivities are over. If you're a pumpkin grower and have had a good crop, you may simply have too many of them to use for cooking or decorating.

Whether pumpkins were part of your Halloween decorating ideas, you've made a pumpkin planter as part of your Thanksgiving decorating ideas, or you simply like them in your pumpkin pie, here's what you need to know about using them as fertilizer.

Basket of assorted pumpkins and squashes

(Image credit: Clare Gainey / Alamy Stock Photo)

Can I use leftover pumpkins as fertilizer in my garden?

The good news is that yes, you can use pumpkin as fertilizer in you backyard. Emily Fernandes, a small-space gardener from California and consultant at HouseGrail, says that 'like other rotting vegetables, fruits, and other things you throw in your compost pile, Pumpkins are full of different things that help fertilize your garden plus help you save money.'

Tammy Sons of Tn Nursery, who has over 30 years' experience in horticulture, including growing many thousands of pumpkins, also praises leftover pumpkins as 'great organic methods of fertilizing those spring blooming garden plants, roses, and other softwood plants. They are packed full of vitamin A, fiber, beta carotene, and nutrients and a sure-fire way to stabilize plants and give them a boost for spring.'

With that said, there are a few important tips and tricks for using pumpkins as fertilizer that will maximize their potential – and prevent any unwanted effects.  

How to use leftover pumpkins as fertilizer

One of the main things to bear in mind with pumpkins is that they are attractive to rodents and other pests that may frequent your backyard. So, you ideally want to hide them in the soil rather than just scattering your pumpkin on top of your garden beds. 

Mindy McIntosh-Shetter, also known as the Outlander Botanist, recommends covering up your pumpkin 'with soil and/or newspaper' – 'burying it in the ground will reduce the chances of attracting pests and will put the organic material in with the soil bacteria that will speed up decomposition.'

Emily also points that 'if you have any seeds left inside, you’ll need to remove them' –unless you want to grow pumpkins on that patch of land. Next, break up your pumpkin into smaller bits, 'use a sledgehammer to mash them. If you can’t use a sledgehammer, you can use a shovel or even cut them up with a knife.' 

Then, 'dig a hole and then put the cut-up or mashed pumpkins in it. Then cover it back up. When it’s time to plant, plant things on the mound.'

Fresh whole pumpkins in a home

(Image credit: funkyfood London - Paul Williams / Alamy Stock Photo)

Can I use leftover pumpkins in my compost bin?

Yes, you absolutely can use leftover pumpkins in your compost bin. Mindy recommends 'creating a lasagna garden' using pumpkin, other kitchen scraps, and old cardboard or newspaper. 

Emily seconds this, advising 'instead of putting the mush in the ground is to add it to your compost pile if you’ve already started one.' 

You can learn how to make compost easily in your backyard, and pumpkin is an excellent ingredient for compost making. Bear in mind that the seed removal and breaking it up into smaller pieces both still apply if you're putting pumpkin into a composting bin.

Anna K. Cottrell is now a freelance writer, having previously been a Content Editor for Future's homes titles. She writes about interior design, property, and gardening. On H&G, she specialized in writing about property – buying, selling, renting – sustainability and eco issues.