Growing cucumbers from seed is fast and easy. They germinate very quickly, and you can either start them indoors or plant them directly into your garden.
In this post, I’ll show you everything you need to know. Even if you’ve struggled with it in the past, you’re sure to be successful after reading my complete guide.
Here you’ll learn all about how to grow cucumber seeds. Including when and where to sow them, the best method to use, exactly how to plant them step by step, how long it takes them to germinate, seedling care tips, and much more.
Growing Cucumbers From Seed
| Days to germination: | 3-10 days |
| When to start indoors: | 4-6 weeks before transplanting |
| When to sow outside: | 1-2 weeks after your last spring frost date |
| Days to maturity: | 50-70 days |
| Sun exposure: | Full sun to partial shade |
| Seed planting depth: | 1” deep |
| Plant spacing: | 12-18″ apart |
| Soil temperature: | 60-80°F |
Types To Grow
There are tons of different types of cucumber seeds you could plant in your garden. The variety you choose depends on what you want to use them for, and your preferred flavor or texture.
A few of my favorites are Marketmore, Homemade Pickles, and Baby Persian. It’s also fun to grow an heirloom lemon variety for something different.
How Long From Seed To Harvest?
In general, the amount of time it takes from when you plant the seeds to when you can expect to start harvesting your cucumbers is between 50-70 days.
Some types are faster than others, so the exact length of time will depend on the variety you have. It also depends on your climate and the growing conditions.
Related Post: How To Grow Cucumbers
Tips For Planting Cucumber Seeds
Below I will give you all the details you need about exactly when and how to plant your cucumber seeds. But first it’s important to choose the best sowing method and prepare for planting.
Cucumber Seed Starting Methods
There are two methods you could use for planting your cucumber seeds: 1. direct sowing or 2. starting them indoors.
They don’t like to be transplanted, and they grow very fast. So I prefer planting them directly into my garden, which is usually the best way to do it. But you can use whichever technique works for you.
- Direct sowing (best method) – Sowing them directly into your garden is usually the best and easiest method to use. This way you don’t have to worry about caring for them indoors or transplanting them later on.
- Starting indoors – Use this method if you have a very short summer, or if your garden soil isn’t ideal for direct sowing. I recommend using either plantable pots or large pellets, which will help to minimize transplant shock.
Related Post: 3 Seed Starting Methods That Every Gardener Should Try
When To Start Cucumber Seeds
You can plant your cucumber seeds directly into your garden a week or two after your last spring frost date. The cold will stunt them, so wait until the ground warms to 60°F or higher. You can use a soil thermometer to check it.
If you want to start them indoors, then you’ll need to plan ahead. In that case, you should sow them 4-6 weeks before the average last spring frost date in your area.
Related Post: When To Start Seeds Indoors
Preparing Cucumber Seeds For Planting
There’s nothing special you need to do to prepare cucumber seeds for planting. You can simply sow them directly out of the packet.
However, soaking them in warm water for 12-24 hours beforehand will soften them up and can help them germinate faster.
Related Post: 13 Unique Cucumber Trellis Ideas
Cucumber Seed Germination Time
One of the reasons it’s so fun to grow cucumbers from seed is because they sprout very quickly. The germination time can be anywhere from 3-10 days.
They will germinate faster in warm soil. So if you want to speed it up, then use a heat mat indoors to keep them warm, or wait to plant them outside until the ground has reached at least 60°F.
What Do Cucumber Seedlings Look Like?
The first two leaves that open right after they germinate are oval and slightly pointy at the tips. Those are called the “seed leaves”.
All of the others that form after that are called “true leaves”, and they look like tiny cucumber leaves. As the true leaves grow larger, the seed leaves will eventually turn yellow and die back.
Related Post: Why Do Cucumbers Turn Yellow & How To Prevent It
How To Care For Cucumber Seedlings
If you planted your cucumber seeds right in the garden, then you can skip this entire section. But, if you started them indoors, here’s how to properly care for your seedlings:
Light
Once they pop out of the soil, cucumber seedlings grow very fast. So it’s important to use a grow light as soon as they germinate, otherwise they will quickly get tall and leggy. A sunny window won’t be bright enough.
Position the light so it hangs 3-4″ above the top of the leaves at all times. Use an outlet timer to make sure they get 14-16 hours of light every day.
Related Post: How To Use Grow Lights For Seedlings
Water
They also need consistent moisture, so never let the soil dry completely. It should always stay damp, but never wet or soggy. Use a moisture gauge and keep the reading between 4-6 to ensure you get it right.
Fertilizer
As soon as your cucumber seedlings get their first true leaves, feed them with a 1/2 dose of organic liquid fertilizer. They love fish emulsion or compost tea as well.
Potting Up
Pot up your cucumber seedlings as soon as they are twice as tall as the original container or seed tray. I recommend using plantable pots made out of peat moss, coco coir, or dried cow manure.
That way the roots won’t be disturbed when you move them into your garden, which will help to prevent transplant shock.
Related Post: How To Grow Cucumbers Vertically
Transplanting Cucumber Seedlings Into The Garden
If you started them indoors, then it’s crucial that you take the proper steps to transplant your cucumber seedlings into your garden to ensure they will thrive.
The first step is to harden them off to prepare them for the transition. Do not skip this, or they may not survive.
They hate the cold, so wait until all chance of frost is gone, and the soil is at least 60°F before planting them into your garden. Use a soil thermometer to check it.
FAQs
If your cucumber seeds won’t germinate, it’s likely that it was either too wet or too cold and they rotted. Wait to plant them until the soil has warmed to 60°F or more, and keep it evenly moist. Otherwise the seeds may not have been viable, so if you’re using older ones then plant 2-3 per hole.
No, cucumber seeds do not need light to germinate. However, the seedlings need 14-16 hours of light daily as soon as they begin to sprout, or they will quickly become leggy.
You can germinate your cucumber seeds faster by giving them plenty of warmth. Keep the soil between 60-80°F at all times. You could also try soaking them before you sow them, which can help to speed things up as well.
Planting and growing cucumbers from seed is simple and fast. No matter which variety you choose, you are sure to be successful if you follow the step by step instructions in this detailed guide.
If you’re tired of struggling, and want to learn how to grow any plant you want from seed, then enroll in my online Seed Starting Course. It’s a wonderful, fun, self-paced course that will teach you everything you need to know to easily grow your own seedlings. Enroll and get started today!
Or, if you just need a refresher, then my Starting Seeds Indoors eBook is for you! It’s a quick-start guide that will get you planting seeds in no time.
Share your tips for how to plant cucumber seeds in the comments section below.
Printable Step-By-Step Instructions
How To Plant Cucumber Seeds Step By Step
Follow these steps for planting cucumber seeds indoors or outside. The instructions are the same no matter which variety you choose to grow.
Materials
Instructions
- Prepare the soil or pellets - When planting outdoors, loosen up the top few inches of soil and remove any weeds. Indoors, pre-moisten the pellets or seed starting mix before filling your trays or pots.
- Decide how many seeds to plant - Indoors, plant one seed per hole or pot. In the garden, sow the seeds 12-18" apart.
- Plant your cucumber seeds - Lay them on top of the soil, and gently push them down about 1" deep. Or you can make the holes first, and then drop the seeds in.
- Cover the seeds - Fill the hole in with soil, then gently press it down to ensure it comes into contact with the seeds.
- Water them - Gently moisten the soil, taking care not to displace the seeds in the process. It should be damp but never soggy or saturated. Use a moisture gauge to get it just right.
- Cover the trays (optional) - Indoors, cover the seed trays with a plastic dome lid, and place them in a warm location. A heat mat will help them germinate faster.
Notes
Cucumber seedlings don't like to be transplanted, and doing so can stunt their growth. If you want to start them indoors, I recommend using plantable pots or large pellets rather than trays. The plantable pots will help to minimize transplant shock.
Gil says
Hello Amy, sure do appreciate you knowledge on Cucumber seeds and I just planted like you said and i have been growning tomatoes for a couple of years and I don’t know much except pinch of the small shoots . If had a Tiller I would do more and also if I really had the know how.
Amy Andrychowicz says
You’re welcome, hope your cucumber seeds will grow great for you!
Ann Kurulak says
I sprouted cucumber seed in a tin foil plate with paper towel on it and was wandering if i can plant the sprouted seed straight into garden i do not want to put individual y into plant pots will i be successful just putting sprouted seeds into garden it is time here in Saskatchewan to put cucumbers in. They sprouted so quick i have never done this before. It was so dry here so i thought sprouting would help and lord behold we got rain. Now waiting to dry up a bit to get these seeds in. I hope you can help me out with this planting episode.
Amy Andrychowicz says
Yes, you can absolutely plant your sprouted cucumber seeds directly into the garden rather than putting them into pots first. As long as there is no chance of frost, and the ground isn’t saturated with water, it should work great. Good luck!
Yannis says
This cucumber is made by a vine. So, get the stick to grow straight.
Here is the step to grow cucumber:
1. Put the seed very carefully in the soil.
2. Water it
3. Wait
4. Wait until the seedling off baby plant grow now.
5. Water it.
6.Water the cucumber plant every day
7. Wait many days so the cucumber plant will grow into a vine.
8. Wait many days to see the cucumber flower
9. Water the cucumber plant
10. When the seedling is growing tall, go outside and water it
11. Wait many days so the flower begin to die to support the cucumber
12. Then you can pick the cucumber to eat.
Did you follow my step to plant cucumber? You do!
Amy Andrychowicz says
Thanks for sharing your tips for growing cucumber seeds. Enjoy!
Kwasi Kwakye says
How many months does it take to mature?
Amy Andrychowicz says
The exact time from seed to harvest depends on the type you planted. But on average, most cucumber varieties take between 50 and 70 days to reach full maturity and start producing fruit.
Libny says
Trying to grow something easy with 9 year old son whom has a love for gardening thanks to grandma lol. I have never grown any food, I’m merely learning how to keep some indoor plants alive. This was helpful. Trying to find an easy trellis.
Amy Andrychowicz says
You’re welcome, glad you found the article helpful. Cucumbers are definitely one of the easiest trellis plants to grow. You could also try pole beans or cucamelons. Those are fun for kids too. Here’s an easy cucumber trellis idea you could try.
Ashley says
I always start my cucumber seeds indoors. For some reason this year they start to grow then they die. I’m keeping them watered and they get plenty of sun. I did start them in the pods that are wrapped in the netting which I haven’t ever done before. Could those be causing them to become root bound and die? I don’t know what I’m doing wrong this year. Last year I got not less than 150 cukes off my plants and I’m afraid this year I won’t get any. I need to be able to make pickles this year.
Amy Andrychowicz says
Oh no, sorry to hear that your cucumber seedlings have been dying. It certainly could happen if the pellets you used are too small for them. Since they grow so fast, I would start them in larger containers. However, many times when seedlings suddenly die off, it’s called “damping off”, which is caused by a disease called “seedling blight”. That happens when your seed trays weren’t properly sanitized. Here’s more information, and how to disinfect them… How To Disinfect Seed Trays And Flats Before Starting Seeds Indoors.
In all honesty, I have much better luck planting cucumber seeds directly into my garden, rather than starting them indoors. They grow so fast, that there’s plenty of time for a good harvest, even in a short growing season like I have. So, you may want to try that, to see how well they do. Wait until the soil is warm, and all chance of frost is gone to direct sow them (late May for us in z4b MN). Good luck!
Jane says
I understand that cucumbers need heat to germinate. I have put my seeds in an airing cupboard with a temp of 21 degrees C. Is this right ?
Amy Andrychowicz says
Yes, that should work. But it is the minimum temperature I would recommend for germinating cucumber seeds. If you can make it even warmer for them (80-90 degrees F), they will germinate faster and more reliably.
Judie Plankis says
I’m growing my cucumbers on a 7′ tepee which my husband built (i’m also growing pole beans on another tepee). How far apart should the cucumber seedlings be? You say to plant them 1″ apart, but what should the final spacing be? The base of the tepee is about 3′ in diameter and there are 8 poles so there should be plenty of cucumbers! I planted 5 different varieties, never thinking about cross pollination. Will that be a problem with all the cucumbers on one tepee? I’ve read a sample of your book (Vertical Vegetables) and immediately requested it from the library. I’m really looking forward to reading it! Thanks!
Amy Andrychowicz says
Yes, you can plant your cucumber seeds about 1″ apart at the base your trellis, that would be fine. But you certainly could space them out more than that if you don’t want to be overwhelmed with all those cucumbers, LOL! Here’s a post with details about how to grow cucumbers on a trellis.
You are likely to see some cross pollination with the different varieties planted that close together. You’d have to plant them on opposite sides of the yard in order to avoid it, but even then it’s still possible for them to cross.
Awesome, so happy to hear that you’re going to read my book, thank you! I hope you’ll love it! 🙂
NURUDEEN says
Nobody is saying anything about its duration. How long does it take for cucumbers to mature on the average? I mean from planting the seeds to harvesting.
Amy Andrychowicz says
Most cucumber varieties take between 50 and 70 days to reach maturity from seed to harvest. Check the seed packet, and it should tell you the duration for the specific type you want to plant.
Ebube says
How do I know the male and female flowers to help me do the manual pollination in cucumber?
Amy Andrychowicz says
The female flowers have a swollen flower stalk that looks like a miniature cucumber. The male flowers have a stalk that is straight and longer.
Rhonda says
We have always direct sown cucumber seeds in raised mounds for heat. The mounds are surrounded by a “moat”. I water the moat. It also does double duty as rain water is caught in the moat and doesn’t wash the seedlings away. We plant all our melons/squash/pumpkins that way. One day I’d like to try trellises at different angles.
Amy Andrychowicz says
Sounds like you have a great system for planting your cucumber seeds! Thanks for sharing. 🙂
Joanne says
I’m new to growing fruit and veg. Pretty much a ‘dummies’ guide haha. Cucumbers were the first seeds I planted. After reading this I think I’m doing it all wrong. The plants themselves are growing quite rapid, but I have them in a vegtrug greenhouse. I notice that the cucumbers on this post are outside. Should I be replanting mine directly into soil or will they be ok in the greenhouse? How tall do they get? Also should I give them some kind of support with a frame, cane etc? I haven’t planted them in the ground as I was worried about cats and foxes. Oh, and the ridiculous amounts of pigeons that poo in my garden!!
Any help for this newbie would be greatly received.
Amy Andrychowicz says
You might be ok growing them in the greenhouse, as long as they get plenty of light. But it’s definitely going to be easier to just plant them outside in the ground once the weather is warm enough. Not all of them are vining plants, there are also bush varieties, so it depends on which type you have. For the vining type, you can use a trellis. Here’s a post I wrote about how to grow cucumbers on a trellis. Otherwise, if you planted a bush variety, then they won’t vine out. Also if you do decided to keep them in your greenhouse, you’ll have to pollinate the flowers yourself (unless you open the doors to let the bees come in).
Ada says
Hi Amy,
My plant grows normally. But some cucumbers turn yellow like picture. Can you give me some advice ?
Thank you !
Amy Andrychowicz says
Sounds like cross-pollination to me. It’s common for them to cross pollinate with squash, melons or other types of cucumbers nearby. Mine turned yellow because I had squash plants right next to them.
Bryan says
Thanks for the info. Can i get the seeds directly from the fruit?
Amy Andrychowicz says
Yes, you can collect the seeds from mature cucumbers.
Thomas says
I agree that cukes are easy to grow and delicious; mine seem to do best on a 45 degree trellis, rather than verticle. However, I am never successful in keeping them going due to a bacterial disease transmitted from the black and yellow cucumber beetles, unless I dust with pesticide, which I hate to do.
I have used seeds that are gynoecious and parthenocarpic, reasoning that since these are self fertile, insect attention would not be necessary, and I could therefore exclude them with light row cover sealed all around. But the beetles always get in!
Any other strategy that might work other than backup planting?
Amy Andrychowicz says
Have you tried growing disease resistant cucumber varieties? A few of my favorites are “Marketmore 76”, “Diva” and “County Fair”, but there are others too. You could also try hanging yellow sticky traps above the cucumbers to trap the pesky beetles, that may help to control them without having to resort to using pesticides.
Thomas says
Thanks for advice Amy. These suggestions I will follow.
Amy Andrychowicz says
You’re welcome!
Daryle says
Hi Amy,
I built a cuke tower several years ago. It’s 22 1/2″ by 22 1/2″ and holds about 10″ of “custom” soil. It has four uprights, one in each corner, that were once called 2 by 2s. Mason twine is strung around at 6″ intervals. There is an “H” reinforcing frame at the top. To make it more fun, it’s on casters.
I plant 4 parthenocarpic cuke seeds on July 4th. I will harvest over 40 full-sized cucumbers before the killing frosts in Vermont.
Amy Andrychowicz says
Wow, that sounds like a wonderful way to go! I love that it’s on casters so that you can move it around.
Alastair says
Amy
Can you advise a beginner on pinching out leaves after 6 leaves form from seed. I am struggling to underdtand which 2 I should pinch out.
Thanks
Alastair
Amy Andrychowicz says
There’s no need to pinch out any of the leaves on your cucumber seedlings.