How Long Do Squash Seeds Take To Germinate? How To Speed Up


If you are planting (or have already planted) squash seeds, you are probably wondering just how long they take to sprout.  You may also be curious about how you can speed up the seed germination process.

So, how long do squash seeds take to germinate?  Squash seeds take 7 to 14 days to germinate.  Squash seeds germinate faster with optimal soil temperature, humidity, and air circulation.

Of course, you can germinate squash seeds indoors and transplant outside later, but it is preferable to germinate squash seeds directly in the soil outdoors.

Let’s take a closer look at some of the factors that affect how long squash seeds take to germinate.  We’ll also see how we can optimize these factors to encourage faster seed germination.

How Long Do Squash Seeds Take To Germinate?

Normally, squash seeds will take 7 to 14 days to germinate (about 1 to 2 weeks, depending on conditions).  The University of Maryland suggests that squash seeds can germinate in as little as 7 days, while Burpee suggests that squash seeds can take up to 14 days to germinate.

squash seeds
Squash seeds take 1 to 2 weeks (7 to 14 days) to germinate if conditions are right.

It will all depend on various factors that affect time to seed germination – let’s get into some of those now!

What Factors Affect Seed Germination?

The time a seed takes to germinate depends on several important factors, such as soil temperature, humidity levels, and air circulation.  Let’s dive into more detail on these factors that affect seed germination.

Soil Temperature

The temperature of the soil (growing medium) will affect the time it takes for seeds to germinate.  Soil temperature will also have an effect on germination rate, or the percentage of seeds that sprout.

***Note: You can find the germination rate on the seed packet itself.  For example, if the germination rate is 95%, then you would expect 95 seeds to sprout out of every 100 seeds that you planted.***

The minimum temperature for squash seed germination is 60 degrees Fahrenheit (15.6 degrees Celsius).  If the soil is any colder than this, you will see low germination rates – that is, if you can get any seeds at all to germinate!  This is nature’s way of protecting squash seeds from sprouting at a time when they will be unable to survive.

The maximum temperature for squash seed germination is 105 degrees Fahrenheit (40.6 degrees Celsius).  If the soil is any warmer than this, germination rates will decrease.  Combined with high humidity, high temperatures can encourage the growth of mold, which is another threat to your plants.

The ideal (optimal) temperature for squash seed germination is between 85 degrees Fahrenheit (29.4 degrees Celsius) and 95 degrees Fahrenheit (35 degrees Celsius).

Keep in mind that these temperatures refer to soil temperature, not air temperature.  If you want to find out the soil temperature, use a probe-type thermometer to check.

If the thermometer reads a temperature that is too low, then you have some options.  One option is to wait until the sun warms up the soil.

To speed up this process, clear away any debris, such as leaves or grass clippings, from the soil surface.  Also make sure to choose a location for planting that gets plenty of sun, so that it can warm up the soil faster.

If you are worried about a short growing season, you can also use a cloche (a plastic or glass cover) to trap some heat and warm up the air and soil near your squash seeds.

For more information, check out the table below, and check out this article from the University of California on ideal seed germination temperatures.

Squash
Seed
Germination
Temperatures
Temperature
(degrees
Fahrenheit)
Temperature
(degrees
Celsius)
Minimum 60 15.6
Ideal 85 to 95 29.4 to 35
Maximum 105 40.6

Humidity

Humidity is another important factor to consider when germinating squash seeds.  If the air is too dry, then the soil will dry out faster, and the seeds will have trouble germinating – they may even die!

If the air is too humid, then the soil will stay too wet, especially if you over water the soil.  This can lead to damping off, which occurs when mold or other pathogens affect seeds or seedlings.

Damping off is more likely with high humidity levels, in moist soil, and at cooler temperatures.

For more information, check out this article on damping off from Wikipedia.

If you find that you have trouble keeping the air and soil humid enough, you do have some options.  One option is to use a cloche (mentioned earlier).

cloches
A cloche does not need to be this fancy – you can make one out of a plastic water container!

A cloche, if sealed, traps moisture in the air and soil so that seeds have the humid environment they need to germinate properly.  A cloche will help your seeds to germinate faster, increase germination rates, and cut down on the time and effort needed to keep soil moist.

Air Circulation

Seeds need air, just like seedlings and established plants.  If the soil is too wet and there is too little air circulation, it can spell death for your seeds before they even have a chance to sprout.

To keep your seeds from suffocating due to lack of air, there are two key things you can do.

First, keep the soil moist, but not wet.  Do not over water the soil, and consider using a cloche to help you to get the right moisture level.

Second, keep the soil loose.  Do not compact the soil by pushing down on it either before or after planting your seeds.  When there is more space between soil particles, there is more space for air and water, both of which are necessary for seed germination.

How Do I Make Squash Seeds Germinate Faster?

If you want to make your squash seeds germinate faster, there are several important actions you can take.

squash seeds
Squash seeds will germinate faster if you take appropriate steps to help them along.

First, protect your seeds from extreme heat and cold.  As mentioned earlier, temperature is one of the most important factors that affect seed germination.

If it is too cold to plant seeds outside, then start your seeds indoors.  This gives you a head start on the growing season, and minimizes the danger of late spring frosts killing your seedlings.  This is especially helpful if you live in an area with a short growing season.

Second, ensure that the soil is moist (not wet!) and the air is humid.  Seeds will not germinate if there is not enough moisture in the soil and air.  Consider a cloche for this purpose.

Third, make sure that the soil has enough air circulation.  This means that you should avoid compacted soil both before and after planting.  It also means that you should avoid over watering your soil.

Fourth, remember that squash seeds do not need light to germinate. If you start squash seeds indoors, give the seedlings bright overhead lights after germination.

Fifth, make sure to plant your squash seeds according to the proper depth and spacing.  Squash seeds should be planted at a depth of 1 inch (2.54 centimeters).  The seeds should be 2 to 3 feet (0.61 to 0.91 meters) apart, to allow each seedling its own space in the soil to grow roots.

Finally, you can scarify (scratch the surface) of your seeds in order to encourage germination.  This can speed up germination and also increase germination rate (the percentage of seeds that sprout).

For more information, check out this article on seeds and seedlings from the Penn State University Extension.

Should Squash Seeds Be Soaked Before Planting?

You can soak your squash seeds before planting to encourage faster germination.  Put them in clean water and let them sit for a few hours before planting.

However, this is not required – as long as the growing medium is moist and warm, the squash seeds should germinate well.

Can You Germinate Squash Seeds In A Paper Towel?

Yes, you can germinate squash seeds in a paper towel.  The paper towel holds moisture and allows the seeds to breathe, serving as an alternative growing medium.

paper towel
You can use a damp paper towel to germinate squash seeds, but you are always better off sowing squash seeds directly into the soil, if possible.

To germinate squash seeds on a paper towel, wet the paper towel until it is damp (not soaking wet).  Then, lay out the squash seeds so that they are separated (not touching).

Be sure to keep the paper towel and seeds in a warm place, to encourage faster germination and higher germination rates.

The only drawback of this method is that you will need to transplant the sprouted seeds into soil by hand, since they will soon need nutrients from the soil to grow and establish stronger roots.  Be gentle when handling the tiny sprouted seedlings!

It is preferable to sow squash seeds directly into the soil outside, since they do not always transplant well.  However, germinating squash seeds in a paper towel may be helpful if you live in an area with a short growing season.

Why Are My Squash Seeds Not Germinating?

There are a couple of possible reasons that your squash seeds are not germinating.

Your Squash Seeds Are Too Old

One common reason for a lack of germination is that the seeds you are using are too old.  In that case, the germination rate may be low, or even zero.

Squash seeds tend to last about 3 years, and germination rates will naturally decrease with each passing year.  For more information, check out my article on how long seeds last.

Your Soil Is Too Cold Or Too Dry

Another reason your squash seeds are not germinating has to do with soil conditions.

If the soil is too cold, then your squash seeds might not sprout right away (whether you are growing indoors or outdoors).  They may sprout when conditions improve and the soil warms up.

However, you might not want to wait that long, and you might not want to risk killing your seeds.  In that case, start the seeds indoors, and use a heat lamp or heat mat to keep the soil warm enough so that the seeds can germinate.  Just be very careful when transplanting to avoid damaging the roots.

Finally, remember that if the soil is too dry, then seeds will not germinate, and they may even die before you have a chance to correct the problem.  Keep the soil moist, and consider using a humidity dome to help maintain the proper moisture levels in the soil and air.

If you have trouble with dry soil, check out my article on how to treat dry soil.

How Big Should Squash Seedlings Be Before Transplanting Outdoors?

Johnny’s Selected Seeds suggests that you should start squash seeds indoors 2 to 3 weeks before it is time to transplant them outdoors.

spaghetti squash
Squash plants like warm weather, and this starts from a young age. Keep the seeds warm (minimum 60 degrees Fahrenheit, 15.6 degrees Celsius) to give them a chance to germinate!

Usually, you should aim to transplant squash seedlings outdoors after the last frost date, since squash plants will not survive a frost.

To find out the last frost date in your location, check out this frost date calculator from the Old Farmer’s Almanac.

Conclusion

By now, you have a good idea of how long it takes squash seeds to germinate.  You also know about the factors that affect time to germination, how to optimize for faster germination, and how to troubleshoot a lack of germination.

I hope you found this article helpful – if so, please share it with someone who can use the information.  If you have any questions about squash seed germination, please leave a comment below.

jonathon.david.madore

Hi, I'm Jonathon. I’m the gardening guy (not guru!) who is encouraging everyone to spend more time in the garden. I try to help solve common gardening problems so that you can get the best harvest every year!

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