Growing Your own Winter Squash Plant

There are few vegetables that are as prolific as pumpkins and winter squashes. On top of its proliferation, growing your own winter squash plant is easy and can be a suitable method of keeping weeds and pests away from other plants.

You can buy a variety of winter squash, all different sizes and different weights. Each with their own quirks.

A quick note, many of the photos on this page have been given by James Pearson and Emily Keenan who grew a proliferation of Crown Prince Squash! Thanks very much!

A particularly heavy Crown Prince Squash
Squash come in a variety of shapes and sizes

The Fine Print

All pumpkins are winter squash. However, there are certain criteria that need to be met for pumpkins rather than other winter squash, which I will discuss shortly. However growing pumpkins and winter squash is the same.

It is quite important to consider the squash plants you grow are quite, well, frisky. That is to say they will cross pollinate with any other squash plant. This will not affect the flavour of the squash you initially get, but will mean the next generation you get will be watery and flavourless mutants.

It is easy to stop the plants from cross pollinating though. When a female flower is forming simply put an elastic band, or a hair bobble around the tip to ensure that no insects can get in, and then once the flower is fully formed and ready to open use the pollen from a male flower on the same plant and fertilise the female plant. I do this with a cotton bud. Remember to close the flower back up after, as you could still get cross pollination otherwise.

Finally, the difference between a pumpkin and a winter squash. There is no botanical difference between a winter squash and a pumpkin. Any squash could be called a pumpkin.

For the sake of this article though, some seed varieties are labelled as pumpkins, others as winter squash. We will use the same titles to save confusion.

Getting Started

Growing your own winter squash plant is easy, but they are hungry plants, so prepare the soil you want to plant them in with lots of manure/compost about 6 months before to let it rot in. I have planted straight into manure, and the plants quite liked this…

Squash plants like warmth and high levels of nitrogen in the soil- hence manure is fabulous.

When planting seeds, they require a warm soil temperature, so germinating on a warm windowsill in modules is perfect, then leave. You want to use pots, or modules, that are about 4 inches in diameter so that the plants can establish decent roots.

Planting Out your Winter Squash Plants

Squash plants do not like the cold, and even a light frost will kill the plants, so you want to plant out only once the risk of frost has gone.

When growing your own winter squash plants you really have two options, either grow in modules as shown above, then plant the seedling out, or plant the seed directly outside.

I prefer the first method, as if a rogue slug gets to your new seedling it does not stand any hope. At least when planting out a seedling it is big enough not to be completely destroyed, however good slug protection is necessary.

If planting seedlings, mid May is usually a good time. Wait until there are three true leaves on the plant. I made the mistake a few years ago of thinking that germination leaves were true leaves. They are not. The plants died. Fail.

Germination leaves are the two initial leaves that look fairly similar on most plants, small, oval leaves. Wait until you have 3 small true leaves before planting out. Then simply dig a hole a little deeper than you need, put some fresh nitrogen rich compost in the bottom and dig the plant in.

As the plant starts to grow it will send off long vines with a mix of flowers. These flowers are male and female; only the female flowers make fruit. If you want to save the seed of the plant, follow the guidance above.

To identify a male and female flower is actually quite easy as well. You can make out the shape of the fruit on the neck of the female flower. Male flowers just have stem and then flower, females have a miniscule fruit already there.

Small winter squash

To Trellis or not to Trellis?

That is a good question. I have seen pumpkins grown up trellises and along the ground and have done it myself with some varieties. Whether you grow your pumpkins up a trellis or not is really dependent on 3 things: the space you have, the size of the pumpkin and the shape of pumpkin you desire.

Honey boat squash growing up a garden arch. A great way to grow them. Please note the slight Mildew on the leaves of the plant when reading further on.
  • The space that you have: some squash varieties can grow! The vines can easily reach 20 feet and so if you do not have that amount of space on your allotment/in your garden, then maybe trellising might be a good idea. You can then train the vine to climb up the trellis.
  • The size of the squash fruit: let’s be honest, you will not be growing an Atlantic Giant pumpkin up a trellis, it would not just look daft and you would not be able to provide enough support to actually do it. I have come across other supports being used, like tights and bras hung off the trellis making a sort of hammock for the pumpkin to sit in.
  • The shape: growing up a trellis can allow you to develop a properly round pumpkin without any pressure points (this also affects the colour, allowing a relatively uniformed tone). When growing on the ground you may end up with slightly flattened parts of the pumpkin or squash. However if you are growing for Halloween you may prefer to have some flatness so that the pumpkin stands up well.

However whatever ever you decide in growing your own winter squash plant, trellising the plants looks beautiful and ornamental.

Tromboncino Squash benefit from a trellis, and look quite stunning as they grow

Harvesting

When you grow your own pumpkin plants, the intention is nearly always to be able to harvest the beautiful pumpkins. It is rare that you might leave pumpkins on the plant, but maybe, if you are using a trellis, you may have wanted to create an ornamental arch? but even still I would recommend cutting the fruit off after the plant dies back.

Harvesting a pumpkin is really easy. Simply wait until the pumpkin is ripe and then cut the stem about 2/3 inches away from the fruit. When cutting you are creating an open wound, which could rot. The further away this wound is from the fruit the better.

Knowing when a winter squash is ripe is the tricky part.

  • Skin colour: you need to know what colour your winter squash should be. If you are expecting an orange pumpkin, it is unlikely to be ripe while still green.
  • The scratch test: a simple test, if you can scratch the surface of the squash with your finger nail, it is not ripe.
  • Sound: ripe squash sound like hollow wood when tapped, whereas unripe squash either sound wet or dull. The below video gives you an idea of how to tap your winter squash. However when you do it, you do not need to use a hammer.
One way to tap a pumpkin/winter squash to see if it is ripe

However, if you do harvest the squash while it is under ripe, you can ripen off the plant without much difficulty. Simply store in a warm sunny location out of the rain, for 6 weeks and you will be sorted.

Pests

There are a few pests that affect all types of winter squash.

  • Grey Mould: affecting plants in damp, warm conditions, especially where there has been damage or a wound. Simply remove damaged areas or the mould can spread through the plant. This is especially important when harvesting your winter squash; you want to leave a clean cut and check that it is healing every few days.
  • Powdery mildew: this is a white powdery growth on leaves of the squash vines and affect winter and summer squash. It can pass from plant to plant but often the plants will be in the same environment. The mildew thrives in warm damp conditions, so try to keep the plants cool and water at the base of the plants rather than around the leaves.
  • Slugs and snails: The little critters get everywhere and can cause significant damage both to young fruit and to the plants themselves. It can be really difficult as winter squash plants have a habit of growing over a large distance. Use your favourite method of removing slugs and snails, from pellets to copper ribbon.

Storing your Winter Squash

It is always easier to store your winter squash whole, and primarily we will show this method below, however, if the pumpkin has been damaged in any way, you may wish to store the fruit in other ways.

  • Storing Whole: By far the easiest and most energy efficient way to store your winter squash. When a fruit is picked, it needs to be cured for several weeks to encourage longer storage. All this means is being kept in a warm dry location for several weeks, every so often turning so that no one place is on the ground/surface for the curing period. Avoid hanging by the stem as this will put pressure on the joint. You could end with the stem coming away from the fruit, leading to a large winter squash splattered across the floor (or, with large heavy pumpkins, a pumpkin shaped hole in the ground!). Once the squash is cured, store in a nice cool environment for, depending on variety, 3-6 months, but at a push these can survive for 12-18 months. If you are trying to live off the grid, only by growing your own food, winter squash are a great veg to store over the winter.
  • Freezing: winter squash freeze really well, either as a mash, or in pieces. It can make the flesh more fragile when cooking with it after, however if you defrost with care you should be OK. Cut the squash into manageable pieces after removing the skin, then place in your sealable freezing container. This is great if there is damage on the skin of the squash, like a hole or bruise. It allows you to store after you have cut it out. If you are growing your own winter squash plant you will almost certainly have some damaged fruit.
  • Powdering: A slightly different way to prepare your squash, however a great way to save space and still be able to use the flesh in soups and as adding flavour to different meals. It does take some effort though. Remove the skin and cut into small pieces then place in your dehydrator, or in your oven. You want to dehydrate for about 24 hours until the squash pieces have shrunk significantly and they are free of liquid. If doing this in an oven you will need to shake every few hours, and keep on the lowest temperature setting. Either way, once dehydrated put the dried pieces into a food blender, or spice grinder, and grind into a fine powder. Spread this out on a board and allow to continue to air dry for another 12 to 24 hours, just to remove any last moisture, then store as you would ground spice.
  • Drying: as above, but simply do not grind into the powder. The pieces can rehydrate in stews quite well, but do go a little soft if cooked for too long. However, this method is excellent for dealing with pumpkin seeds. Once these seeds are dehydrated fully you can remove the outer husk and place the inner seeds back into the dehydrator. This is time consuming and boring but allows you to be able to prepare these pumpkin seeds for eating. The inner seeds will need about 12 hours in the dehydrator at a high setting. Then store like you would any other spice.

Seed Varieties for Growing your own Winter Squash Plant

  • Atlantic Giant – Suttons Seeds: a huge pumpkin variety, perfect for winning competitions. Only grow one fruit per plant and you will need to feed weekly with high potassium feed. 10 seeds, £2.99.
  • F1 Becky – Suttons Seeds: beautiful medium sized pumpkins, perfect for carving for Halloween. Very prolific plant. 20 seeds, £2.79
  • Hundred weight crafty pumpkin – Suttons Seeds: Nice big round orange pumpkins, perfect for Halloween carving and for eating. The flesh is yellow and can be used in a multitude of ways, but you can also eat the leaves like spinach. 20 seeds, £2.49
  • Amazonka Pumpkin – Suttons Seeds: smaller fruit but with a great flavour. These are striped orange and great for roasting or in soups. Not grown for carving. 20 Seeds, £1.79

One other option for you, only for you who are most dedicated: why don’t you try breeding your own squash plant? Real Seeds have a scheme for you to try just this. If you are especially interested in pumpkin like varieties, then try to get your own. It will take multiple years for you to get a stable variety, but you can have your own pumpkin variety! What fun!

A variety of squash, called a spaghetti squash. The flesh turns into fine strands when cooked, like spaghetti.

Once you have started to grow your pumpkins come back to us and have a look at the range of things you can do with them, from pumpkin soup to using them in tagines. A great vegetable for storing and eating.