When to thin seedlings?

How to grow cucumbers

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Cucumbers are delicious – especially when you’ve grown them yourself. They’re also really easy to grow. You’ve just got to understand that there are two main types – greenhouse and outdoor plants. Each requires a different treatment to produce a good crop.

You can grow cucumbers regardless of how much space you have. They can be successfully grown in pots, growing bags or directly in the ground. Here’s how.

What are the two main types of cucumber?

Ridged cucumbers like these are grown outdoors.
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There are two main varieties of cucumber: greenhouse and outdoor. Greenhouse cucumber plants produce long, smooth fruits, much like the ones you find in the supermarket. These plants don?’t need pollinating – in fact, you should remove any male flowers to prevent pollination happening or the fruits will end up bitter. You can buy all-female F1 hybrid varieties, such as cucumber bella, so that this won’t be an issue.

Outdoor varieties, meanwhile, are called ridge cucumbers. They tend to be shorter, plumper and they’ve got a rougher skin. These need to be pollinated as they produce male and female flowers. But this isn’t usually a problem as insects will most likely handle this for you!

How do you grow a cucumber from seed?

When you plant your seeds depends on where you plan on planting them.
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Cucumber seeds should be sown in a propagator between March and April. But you can get started in February if your greenhouse is heated, and in May to June if you plan to sow the seeds directly outdoors.

Sow the cucumber seeds on their sides at a depth of 1cm in 7.5cm pots of free-draining, seed sowing compost. Place the pots in a propagator or seal them inside a plastic bag at a temperature of 20°C until they germinate. This usually only takes 7-10 days.

Once they’ve germinated, you can move them to a bright windowsill and grow them there until they’re big enough to be transplanted. A few things to keep in mind:

  • • Try to maintain a minimum temperature of 15°C
  • • Keep the compost moist but not wet
  • • Keep them out of direct sunlight – cucumber seedlings can be prone to scorching
  • • Try to avoid disturbing the roots when you transplant them

Growing Cucumbers in a Greenhouse

Encouraging cucumbers to climb in a greenhouse produces better yields.
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When do you plant greenhouse cucumbers?

If your greenhouse is heated, you can plant the young plants in late March. If it’s not, wait until late May. Keep the potting compost moist – the rule of “little and often” applies here.

How do you plant greenhouse cucumbers?

Plant two cucumber plants per grow bag, or at a distance of 45cm apart.

How do you look after greenhouse cucumbers?

Keep the greenhouse warm and humid by regularly spraying or damping down the pathways. You might need to screen plants to protect them from scorching on very hot days, and a little liquid fertiliser every two weeks or so will go a long way.

What should you do with trailing types?

If you encourage the plants to climb, you’ll get better yields. So, train the main shoots to climb a vertical cane or string and, once they reach the end of their support, pinch out the growing point at the top of the plant. Pinch out the end of each side shoot once the fruit begins to develop, leaving two leaves after each fruit. This helps to encourage more sideshoots, which will produce bigger crops of cucumbers.

What to do about male and female flowers?

Always remove the male flowers from greenhouse cucumbers – you can tell they’re male because they just have a plain stalk. (Female cucumber flowers have what looks like a tiny cucumber between the bottom of the flower and the stem).

Which greenhouse cucumber varieties should you try?

  • • ‘Carmen’ F1 AGM: A unique variety that’s all-female and is admirably disease resistant. The plant is easy to train in a greenhouse and produces abundant crops.
  • • ‘Cucino’ F1 Hybrid AGM: Crisp, flavoursome mini-fruits are prolifically produced from this plant throughout the season.
  • • Nimrod: Compact, manageable and less likely to take over than some varieties, this plant produces dark-skinned, crisp cucumbers.
  • • Mini Munch F1 Hybrid: All-female, this variety is a particularly heavy cropper if harvested regularly.
  • • ‘Bella’: All-female, vigorous and with a good tolerance to powdery mildew, this is a reliable variety – even in unheated greenhouses.

Growing Cucumbers Outdoors

Grown outdoors, cucumber plants can trail along the ground.
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When do you plant outdoor cucumbers?

Ridge cucumbers should be gradually acclimatised to outdoor conditions over 7-10 days before transplanting into warm, well-drained, humus-rich soil.

Where should you plant outdoor cucumbers?

Choose a sunny position that’s sheltered from strong winds.

How to plant outdoor cucumbers?

Plant them in single rows 90cm apart. They won’t need training onto canes – just let them sprawl across the ground.

How to look after outdoor cucumbers?

Ridge cucumbers can be pinched out at the main stem after seven leaves have formed, to encourage fruiting side shoots to develop.

What to do about male and female flowers?

Outdoor ridge types require pollination by an insect. The plant therefore needs both male and female flowers to be present, so don’t remove the male flowers from these varieties.

Which outdoor cucumber varieties should you try?

  • • ‘Masterpiece’ AGM: Short and straight, these cucumbers are dark-green in colour.
  • • ‘Marketmore’ AGM: Disease-resistant, tasty, and prolific, this is a very popular variety.
  • • ‘Crystal Apple’: A heritage variety, this plant produces prolific golf-ball-sized fruits (if picked regularly) with crisp, sweet, tender flesh.
  • • ‘Burpless Tasty Green’ F1 Hybrid: High-vitamin content and flavourful, these cucumbers are crisp and delicious.
  • • ‘Jogger’ F1 Hybrid: A reliable variety that performs well even during poor growing seasons, the fruits it produces are crisp, yet juicy, and not bitter.
  • • ‘Goblin’ F1 Hybrid: These snack-sized mini cucumbers have a semi-trailing habit and grow well in containers.

Are There Indoor-Outdoor Varieties?

Check the variety you’ve got – some can be grown indoors or outdoors.
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Some varieties can be grown equally well in a greenhouse or outdoors. The ‘Swing’ F1 Hybrid (all female), for example, produces a heavy crop of long, crisp cucumbers that are ideal for organic gardeners. The ‘Diva’ (all-female) produces high yields of seedless mini cucumbers – perfect for snacking!

The important thing to remember when choosing where to plant is that you should never grow ridge cucumbers in the same greenhouse as an ‘all-female’ greenhouse type; this will lead to cross-pollination, and your fruits will taste bitter.

How to harvest cucumbers?

Use secateurs or a sharp knife to cut the cucumbers from the plant.
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You can normally begin to harvest cucumbers around 12 weeks from sowing – how long the cucumbers are will depend on the particular variety. But it’s best to harvest cucumbers while they’re young and tender, before they show signs of producing seeds, as older fruits can become bitter.

Harvesting cucumbers is best done early in the morning when temperatures are cool. Cut the fruits from the plant using secateurs or a sharp knife.

Regular harvesting will encourage long continuous production. Outdoor types can continue to fruit until September, while greenhouse types can fruit into October if temperatures are warm enough.

Top tips for growing cucumbers

  • • Keep your cucumber plants well watered to help them establish and to increase yields. You want them to be moist, not wet, so little and often is best.
  • • Feed your cucumber plants with a high nitrogen feed every two weeks.
  • • Cucumber plants like sun, but are prone to scorching, so some shade is preferable.
  • • Encourage greenhouse varieties to climb to boost yields.
  • • Harvest fruits early in the day while it’s cool.
  • • Harvest frequently to get more fruits during the season.

Now you know how to choose and grow the best cucumbers, you just need to find plenty of ways to eat your bumper crops. We like ours sliced into sandwiches and added to long cold summer drinks to enjoy as the sun goes down! Check out our full range of salad seeds here. Happy growing.

How to Prevent and Fix Leggy Seedlings

After seeds germinate, do your leggy seedlings look weak and straggly like this? Need some help?

The stems on leggy seedlings are long and thin, but there are few or very tiny leaves.

What Causes Leggy Seedlings?

‘Leggy’ seedlings typically have stretched skinny stems and look fragile. They may be bending forward rather than growing up straight with a strong stem.

If your newly germinated seedlings look like this, it may be due to one of three common causes:

  1. Insufficient Light. This is the usual reason why leggy, tall thin seedlings develop. Young seedlings can struggle to access adequate light (from the sun, an indirect source or a heat lamp).

If lack of light is the issue causing leggy seedlings, this is easy to fix!

  1. Lack of Soil Moisture. Baby plants can grow weak, skinny stems if the seed raising mix dries out or is poor quality. Maybe you just forgot to water often enough! Dry soil stops the seedlings from accessing the nutrients they need to grow strong stems and leaves. They’re literally starving, poor little darlings.
  1. High Temperatures. Heat can also cause a rapid growth spurt. This causes the stems to grow faster than the leaves. So the seedling has unbalanced growth. They look like they’re ‘all legs with a tiny head’! This can occur in hot weather or indoors if the temperature is too warm.

“Mistakes are tools for learning. Evaluate your trials. Making mistakes is a sign you’re trying to do things better. There is usually little penalty for mistakes if you learn from them.” – Toby Hemenway, Author Gaia’s Garden

4 Factors to Consider with Leggy Seedlings

Should you abandon your babies and start raising seeds again? Or can they be rescued and grow into healthy adult plants? That depends!

1. Are these seeds the only ones you have? If so, they’re probably precious and are worth putting a little effort into saving.

2. Do you have plenty of seeds? If these ones only germinated in the last week or so, maybe you can just start again. You really haven’t lost much.

3. Are you sowing late in the season? This determines how much time you have to play with. If you don’t raise these babies now and get them into the soil, will you miss the window for planting?

Time your seed sowing to increase germination rates and promote healthy strong seedlings. I use a moon gardening calendar to help me know the best planting times so I swing things in my favour!

4. What cycle of the moon is it now? You may be able to use it to your advantage. If it’s an optimum time for seed raising within the next few days, starting again may be a good idea. Even as a backup plan! You will likely end up with stronger seedlings that germinate fast and may well overtake these ones in growth anyway.

It’s all about TIMING!

“If your seedlings are leggy, it may also be because you sowed them at a time of the month when plant energy is low and dormant.”

Maybe you’ve had success one month, but had leggy seedlings the next time? Couldn’t figure out what went wrong? Maybe you blamed the seed company unfairly when they failed? It could just have been you sowed at the wrong time! Right season, but not the best time of the month.

If so, it’s likely got to do with getting your TIMING right. I’ve learned to avoid sowing in a 4 day window each month because it’s a waste of time and money. Seeds consistently fail at that time. It’s made a massive difference to success and it’s a simple thing to do.

I follow an easy-to-use perpetual Moon Calendar when raising seeds. I simply sow herbs and vegetables on the days they’re most likely to germinate faster, which saves time and gives the best chance of success. If you want a consistent supply of fresh greens on your table or are raising microgreens to sell, you can save yourself a whole lot of headaches. How? Just sow seeds when soil moisture conditions are in your favour.

How does it work? Just like the tides come and go every day, the gravitational pull of the moon affects seed germination at different times of the month. During the new moon phase, soil moisture is absorbed into the seed faster, so it swells and germinates. Then as the seedling develops a stem, moisture is pulled up in the plant sap, accelerating growth.

It’s just a simple way to work with nature. Gardeners have been growing this way for thousands of years! Now you know, you can time your seed sowing with the ideal moon phase.

“Keep on sowing your seed, for you never know which will grow – perhaps it all will.” – Albert Einstein

How to Fix Leggy Seedlings

If you’ve decided you want to nurture your seedlings back to good health, the solutions are quite simple.

There are some simple fixes for leggy seedlings

1. Sufficient Light

Are your plant babies leaning toward a window or light source? If so, turn them around daily so they grow up straight instead of bent. Ideally, move them to a more suitable spot where the light is stronger. e.g. Close to a window indoors, in a greenhouse or protected outdoor location. Or use a low cost grow light if growing indoors.

2. Dry soil

This may be obvious, but you could try watering more consistently!

  • Wicking tray. One way to water your seedlings is to add a small amount of water to a shallow tray or container. Sit your pot or seed raiser inside the tray. Allow the soil to ‘drink’ up as much moisture as needed. Not too much though. You don’t want your seeds to rot!
  • Set a reminder on your mobile for a daily seedling checkup.
  • Keep a spray bottle handy beside your seedlings. This may also prompt you to water regularly.

Mist with a fine spray to keep the soil moist.

3. Poor quality seed raising mix

Change or make your own seed raising mix. If your soil mix dries out too fast, it may not have the ideal properties you need for it to consistently hold adequate moisture. A good quality mix should feel moist, but not too dry or too wet. Too much moisture, seedlings rot. Too dry and they starve and become skinny and weak.

That’s why I make my own seed raising mix. It’s quick and simple and you can too. I share 5 DIY seed raising mix recipes you can use here. I raise thousands of seedlings each year and want nutrient-dense, healthy microgreens.

“Whether you’re raising seedlings to eat or sell, your seed raising mix is a critically important ingredient for success.”

4. Too hot

Move your babies to a cooler spot or provide shade protection with filtered light. Ensure they have adequate moisture if the weather is warm.

5. Transplant

If your seedlings are mature enough for transplanting, this may also solve the problem. Gently move your seedlings to a protected area to sun harden them for a few days. This will encourage them to strengthen and get ready to ‘move house’ into the big wide world of your garden!

If your tomato seedlings have long leggy stems, one solution is to plant them deep.

Bury at least two thirds of the stem under the soil. This can encourage the seedling to grow new roots along the buried length of the stem.

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How to Prevent Leggy Seedlings

What steps can you take to avoid leggy seedlings?

  • STEP 1. Next time you sow seeds, choose a sunny position with good light and ventilation. Then your babies can grow without frying in the heat or straining for sunlight. A mini greenhouse may help control temperature and light.

Seeds germinating into healthy seedlings in punnets with good light and moisture

  • STEP 2. Be observant daily. Don’t wait until a problem occurs. Prevent it earlier. Diagnose any issues before they become too difficult to resolve.
  • STEP 3. Time your seed sowing to work in with the moon cycle. This not only encourages earlier seed germination but plants grow stronger from the start. When they are transplanted into your garden, they are more likely to be resilient to pests and diseases too. A healthy, strong seedling will give you the best chance of success.

  • STEP 4. Out in your garden, self-sown seedlings are naturally blown about by the wind. This helps them develop stronger, thicker stems from ‘birth’. If you’re raising seed ‘babies’ indoors or in a protected environment, use a fan to blow air over your seedlings daily or run your hand over them gently several times. This gentle movement imitates nature. Cool hey? Nature knows best! I show you how in this video.

Want to learn more about raising seeds?

Check out my:

  • Seed Starting Guide – Quick Tips for Starting Seeds Successfully
  • Easy Guide to Growing Microgreens
  • 12 Valuable Tips to Grow Healthy Microgreens
  • 5 Mistakes to Avoid when Raising Seeds

Hope these tips help you raise lots of healthy plant ‘kids’ in your garden! If you enjoyed this article, please remember to share.

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Novice Gardener – Should I thin out seedlings?

Thinning and transplanting seedlings
by: Megan
If your seedling haven’t grown too big, definitely carefully pull out some of the crowded small lettuce plants out. If it disturbs the soil and other plants, then snip off the heads of some seedlings, enough to create a bit of space around each plant.
If your seedlings are big enough, but really crowded, snip off some plants and use them in salads. If you want to transplant them all and don’t have a patch of garden, 8oz pots are very small and you will constantly have to add nutrients and water, as the roots of even one lettuce plant will fill up the pot. Two plants to a pot is OK, but only if you use much bigger pots. Transplanting seedlings is best done when there are at least 4 leaves on the plants.
Depending on the variety of lettuce, you need roughly 15cm (6″) space between each plant. Many people do sow closer so they get an early few meals of the young seedlings when they do thinning out.
If plants don’t get enough space, they can grow stunted by having to compete for light, nutrients, water and root space.
A packet of seeds will last many gardeners a couple of seasons at least, sowing at 6 weeks to 2 monthly intervals from spring to winter.

Everyone complains about weeding but that may not be the worst gardening job. There’s nothing I dread more than having to thin my seedlings. Thinning isn’t the most labor intensive job but it feels sad to kill plants I’ve worked hard to keep healthy. However it is an incredibly important step if you want a good harvest.

While you may be tempted to plant to your desired spacing and avoid thinning altogether this is not ideal. First and most obviously, starting more seeds will ensure you get a harvest even if you have less than ideal germination. Secondly many plants thrive with a little competition in the beginning. Thinning is important for plants to grow well but in the beginning competing with other plants can make your seedlings more vigorous.

Ultimately though plants will need to be thinned. As plants grow they compete for resources and this can weaken them and hurt your harvests.

Thinning ensures growing plants have adequate space.

Some vegetables can be grown in small areas if they get enough other resources such as plentiful water and nutrients however there’s always a limit. For example, root vegetable harvests will suffer tremendously without optimum space. Avoiding thinning will leave you with spindly carrots and thumbnail size beets.

It ensures plants have proper air circulation.

If plants don’t have plenty of air circulation they can be prone to pest and disease issues.

Thinning also helps ensure healthy plants.

When you thin plants you should thin any that show any signs of weakness or disease. You want to keep your best plants for a productive harvest and if you choose to save seed you’ll know you’re saving from plants that performed the best from the start.

Plants that are properly thinned will get adequate water.

In some areas you may be able to provide plenty of water to thinly spaced plants however if you experience any droughts it’s always better to have a safety buffer.

Properly spaced plants will get enough nutrients.

While you can sometimes grow plants closer together than recommended if you are meticulous in your soil management and add a lot of amendments it’s not a always a good idea. If your plants have to compete with each other for nutrients they’ll be less productive and more prone to disease and pest issues.

Tips

  • To avoid damaging other plants roots as you thin you can just use scissors to cut your plants off as close to the ground as possible rather than pulling them.
  • Water your plants after thinning to ensure any that may have been disturbed re-establish well.
  • Check out this post to learn about when we thin corn plants.

Thinning plants is never easy but it must be done! Overall the best advice for thinning plants is simply, be ruthless. No one likes to thin their plants but trust me, a poor harvest will be more devastating than killing a few now.

Have you planted all your garden seeds, and now they’re starting to sprout? That’s excellent! This also means it will be time to thin them soon. As painful as it may be, it is best to thin your seedlings down to the one healthiest sprout per cell space or container after the first couple sets of true leaves appear. Thinning is a very important step in the seed-starting process to result in the most healthy, successful plants possible! They will thank you with explosive growth!

This post will discuss several methods of thinning, their pros and cons, what to do with the thinned seedlings, and other best practices. A thinning demonstration video is included at the end! If you’re interested in tips for starting seeds, read more here.

One bench in the greenhouse, just three weeks after we sowed all of our seeds! Look how crowded it is in here! Definitely time to thin.

Why thin seedlings?

When left un-thinned, seedlings that are in tight quarters will compete with one another for nutrients, water, air, and root space. Those are not things you want to deprive your seedlings of! In addition to concerns about competition, crowding seedlings also increases the risk for disease. This is primarily due to the reduced airflow between the plants. Bad guys like powdery mildew love cramped conditions, and also spread spores when leaves rub against one another. All of this applies to seedlings (or plants) that are started indoors in containers, and outside in the garden.

When to Thin Seedlings

It is best to wait until a couple weeks after sprouting, once the plants have developed a set of true leaves or two, but to not wait too much longer after that. The “true leaves” are the ones that emerge after the first set of sprouting leaves. Those very first ones are the embryonic leaves, called cotyledon, and are often times heart-shaped and indistinguishable between different types of plants. The true leaves more closely resemble what the mature plant leaves will look like, but miniature. Once a few of those pop, it helps you scope out the best looking seedlings.

When it comes time to thin, you get to choose the strongest, healthiest, best-looking seedling to keep around. After thinning, the chosen keepers will take off and thrive! Seedlings can quickly become four times the size of the ones that were left unthinned, in just a matter of weeks! Leaving them un-thinned stunts their development immensely. I have experimented and experienced this first hand, numerous times!

HOW TO THIN SEEDLINGS

Like many aspects of gardening, this is sort of up to personal preference… but here I will share the two methods we primarily use: trimming, or gently separating apart.

A third option is to pull up on the unwanted seedling, manually plucking them out of their container – sometimes with the hopes of keeping the pulled seedling to replant. We do not use or encourage this practice since it can be a bit risky. Not only might the roots of the pulled seedling get damaged, thwarting your efforts to save it, but the seedling you are hoping to save and leave behind in the container may get damaged or completely pulled up along with it.

Thinning Seedlings by Trimming

Our preferred method to thin most types of seedlings is to trim out the unwanted ones. We simply snip off the smallest, thinnest, or leggiest ones at the root line with small sharp trimming scissors, leaving the chosen one behind. We really love these trimming scissors and have several pairs! They’re frequently used on this homestead for many projects.

This is how we thin pretty much all of our vegetable seedlings, whether started in containers or directly sown outside. Aside from trying to reduce potential damage, we also just don’t have the need to save the excess ones. With limited space in the raised garden beds and under the lights in the greenhouse, what the heck would we do with all those additional salvaged plants? We already start more than we intend to grow, as extra insurance. We do not have room for dozens more tomatoes, peppers, or squash on top of that.

The thinning by trimming process. Those swiss chard will be much more happy now!

Benefits of Trimming:

By cutting instead of pulling, it prevents accidentally distributing the one you’ve chosen to keep – the strongest and thickest looking babe. Since we are not attempting to keep the ones we have thinned out by trimming (as you may do if you are separating them, discussed below), there is no need to pot up or plant out anything at the same time. This makes the thinning process via trimming very quick and easy! All we have to do is snip, and move on.

Note that we also start most of our vegetable seedlings in 4” pots or large cell 6-packs (as opposed to tiny peat pellets or smaller cell packs) which also reduces the urgency to pot them up early. This makes trimming even more appealing for us, as the plants do not need to be fussed with for any reason at the time of thinning. The plants will all be happy in their homes for quite a while, especially after they are thinned.

Potential Drawbacks:

Some people view the loss or “death” of these extra seedlings as a negative thing – an overlooked potential of future plants, or even as a waste. But we do not view it this way! Here is why:

Microgreens!

The ones we cut aren’t “going to waste” just because we don’t replant them! The thinnings are nutrient packed micro-greens. We eat them. Or most of them at least.

Which seedlings are edible? So many types! For example, any baby greens like lettuce or kale, other brassicas like broccoli or kohlrabi, or basically any veggie that you could otherwise eat the foliage of – are edible microgreens! You will find a more complete list below.

These make for an excellent salad or meal topper! We use them mostly raw but can be cooked as well. They also make for a super high-class chicken treat. After cutting them, microgreens stay most fresh and crisp if refrigerated inside a sealed container, like a glass tupperware or ziplock-type bag, with a tiny splash of water in with them.

Here is a list of edible seedlings,
and also those you want to avoid consuming

Edible Microgreens Do Not Eat – Compost instead
Kale
Spinach
Radish
Arugula
Beets
Carrots
Celery
Turnips
Pea shoots
Cabbage
Collard Greens
Mustard Greens
Basil or other herbs
Lettuces
Onion/Leeks
Swiss Chard
Bok Choy
You get the point. A lot!
Tomatoes
Peppers
Eggplant
Cucumber
Melon
Green Beans
Potato greens – except for
sweet potatoes, they’re okay!
Rhubarb leaves are toxic!
Squash are a maybe?
Some cultures enjoy
eating pumpkin leaves!

Look at all these micrograms we ended up with from thinning!

Thinning Seedlings by Separating

Another method used to thin seedlings is by gently separating them. To do this, carefully remove the whole chunk of soil, seedlings and roots out of their small container. You can usually accomplish this by by gently tipping the container on its side and easing the mass out, pushing up from the bottom as needed. Do not pull up on the seedlings themselves!

Gently break up the soil and pull the seedlings apart. As much as possible, take care not to forcibly rip the roots apart if they’re tangled together. Next, either immediately re-pot the ones you want to keep, or get them planted outside – but only if they’ve been hardened off first! (Post coming on hardening off next week!)

I use this method most often for flower starts, like sunflowers and zinnias. In my humble opinion, there is alwaaaaays more room for flowers in the garden! Especially zinnias, because they’re a monarch favorite! So I like to try to keep as much of those babies alive as possible. They’re usually pretty hardy and can handle this treatment. Also, we usually plant out flowers a bit earlier and smaller than our veggie starts. This means that when I separate them, I can plant them straight outside right then, not needing to repot them. We also do this with fava beans. The tomatoes and peppers need to be babied in the greenhouse for a bit longer.

Demonstrating the separation method with zinnia seedlings.

Benefits of Separating:

One benefit of pulling apart seedlings is that you can exponentially increase the number of plants that you are keeping. You could also potentially increase the number of plants that you’re able to start in a smaller space.

For example, if you only have one small shelf and grow light, you could fill one tray with six 6-packs. By using the trimming method, cutting them down to just one plant per cell, the result would be 36 plants. But if instead you separate out the multiple sprouts from each cell, you could easily end up with over a hundred plants! That is a lot of bang for your buck. However, once you separate them, they do need to go somewhere. That leads us to the potential con of this method:

When you separate out seedlings, but it’s not yet time to plant them outdoors (e.g. they’re still too young and tender, you haven’t hardened them off yet, or there is still risk of frost) then they’ll need to be potted into individual containers. If we are following the previous example, now what are you going to do with 100 individual containers? Even if you have room for all those in your garden, do you have space and light to keep them happy in the meantime – until they go outside?

Another drawback of this method is the time that it takes. If you need to either pot them all up or plant them all out at the same time as thinning, it makes the process of thinning much more labor-intensive. This can make you less eager to get the task done and procrastinate on thinning, which isn’t in the best interest of the plants! I have felt this way several times, and feel similarly about potting up.

The final potential issue with this method is the risk of harming the plants. As long as you’re gentle and separate them early, many plants do okay with some root disturbance. They usually will not die, even if handled a bit rough. But when I do have to get rough with them, I can’t help but think “How would they have done if I hadn’t torn them apart like that?… Would they be even larger and more robust?”, especially if the plants are doing just so-so out in the garden later. Because while they may not die, root disturbance can cause a slight shock and setback in development.

Some plants have a super sensitive, delicate root system, and do not like to be disturbed at all.

These are ones that should not be thinned using the separation method. They should either be started directly outside in their final destination (called direct-sowing) or use the trimming method to thin them instead.

The following plants do not like to be transplanted, or are sensitive to root disturbance:

  • Beans – direct sow preferred, though early gentle transplanting can be successful
  • Nasturtiums – direct sow preferred
  • Carrots – only direct-sow in place
  • Radishes – only direct-sow in place
  • Squash and Zucchini – okay to start indoors, but do so in a large enough container that they will not become root bound, and transplant out and/or pot up before they do
  • Beets – same notes as squash
  • Spinach – same notes as squash
  • Peas – same notes as squash
  • Melon – same notes as squash

Alright folks! That is the low-down on thinning seedlings! My thoughts and experience with thinning seedlings, that is.

Here is a demonstration video of everything we just discussed!

To view this video direclty in YouTube, or visit our channel,

So, whaddya say? Are you feeling a little less nervous about the situation, and ready to go snip off (or separate) some babies?!? Baby plants, I mean…

If it was time to thin your seedlings, it may also be about time to fertilize your seedlings for the first time too! Check out this post all about how, why, and when we use seaweed extract to fertilize seedlings. It is a gentle, sustainable, and effective multi-purpose organic fertilizer. We love it, and so do the plants!

I hope you found this helpful! If so, share it! Feel free to ask questions in the comments below.

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