How to sow seeds – beginners guide to growing plants
Lee Burkhill: Award Winning Designer & BBC 1's Garden Rescue Presenters Official Blog
Updated 2024: It's amazing to think that most of the plants in your garden can be grown from tiny, unassuming seeds. These little seeds of life allow plants to propagate themselves and spread joy with us gardeners wanting to grow our own. You can grow anything you want in your garden, from vegetables to herbaceous perennials like flowers and even trees!
Seed sowing is a simple science, but many new gardeners get it wrong. The excitement seed sowing brings can also bring a slapdash or misinformed activity that leads to plants failing to succeed.
This beginner gardening guide on how to sow seeds will show you how to sow, grow and succeed with seeds. (There's a tongue twister!) Whether growing plants to eat or just for their beauty this guide shows you everything you need to know to start growing your own plants.
The beauty of sowing seeds is the sheer variety of plants you have at your disposal. You're not stuck with whatever trend your garden centre is pushing. Like that tiny seed embryo, you can break free and create your own personalised garden- just for you.
Let's take a quick look at the benefits of growing your own plants from seed.
Growing plants from seeds can be much cheaper than buying established plants from a nursery. Seeds are relatively inexpensive and can produce a large number of plants for a fraction of the cost.
Growing plants from seed allows you to access a wider variety of plant species and cultivars than you might find at your local nursery or garden centre. This gives you the opportunity to experiment with different types of plants and find the ones that work best for your garden.
Watching a plant grow from a tiny seed into a fully grown plant can be incredibly rewarding and satisfying. It's a great way to connect with nature and experience the wonder of the plant world and become an advanced gardener!
When you grow plants from seed, you have complete control over the growing conditions, from the soil and nutrients to the amount of light and water. This can result in healthier plants and better yields. You can tweak all the conditions to either grow things earlier in the season or to grow bigger plants by feeding them more.
Growing plants from seed can be a more sustainable and eco-friendly option than buying established plants, which often come with plastic pots and packaging. By using biodegradable seed starting materials, you can reduce waste and minimize your environmental impact.
The first step before you rip open your seed packets is to select the right growing medium. Choosing seed compost which is lower in nutrients, is vital. High-nutrient feed can inhibit germination and is a waste of good compost.
I would urge you to think twice about using really old dusty compost you've dragged out from behind the shed. If you're taking the time to sow, nurture and then pot on your seeds, the right seed compost mix is the essential first step. Old compost can be full of fungi and pathogens, which will kill off your seedlings.
Choosing the right seed compost can also help you dodge some issues when using the wrong growing media. Dampening off, mildew, disease or funky smells from your seed trays can all be avoided. I'm using Dalefoot Seed compost, which is completely natural and a mix of sheep's wool and bracken.
I'm using Dalefoot Seed Compost, which is 100% natural and made of bracken and wool.
Many new gardeners tend to use the wrong pots when sowing seeds. By sowing seedlings in large deep pots in the belief that all this extra room and compost is beneficial to the seed. Whilst your intentions are noble, all you will waste compost and take up vast amounts of precious greenhouse or windowsill space.
Seed trays are relatively shallow trays where seeds can be sown efficiently over a larger surface area. The majority of commercially available seeds need the following to germinate.
That is all a seed needs to germinate. They don't need huge amounts of nutrients as the seed itself has everything inside that it needs to send out those first seed leaves and start photosynthesising!
Plastic trays are probably the cheapest and most widely used form of the seed tray. However, if you've been following my #plasticfree gardening series, you will know that there are plenty of other alternatives when sowing seeds. You can also check my blog on Episode Two of my vlog series, which covers the other seed tray options.
You have a plethora of seed tray and pot options. Choose wisely between biodegradable and recyclable options when possible..
Once the seeds have a set of true leaves, you can prick them out into larger pots. So the seed tray is just the catalyst for germination. Save all that compost and our fancy pots for a bit later on!
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Fill your seed trays with quality seed compost using your hands, a bucket, a sweet shop scoop or an empty pot. Whatever floats your boat, the same goes for whether you want to wear gloves to protect your gel acrylics or get all Mother Earth and go hands-free!
Fill the seed tray 2cm or 1 inch from the top of the tray or pot.
Then, you need to tamp it down, basically, to compress the compost to remove air gaps and provide a level surface for the seeds. If you don't do this when you water the tray, the soil will bubble and then settle in an uneven fashion. This isn't great for seeds as they will tend to fall into these gaps and all germinate at potentially different rates.
You can buy special wooden tampers or make your own, like me, with a piece of wood. Don't get too hung up on the material. As long as it's level and you can pick it up and down quickly, then it will be fine.
Fill your seed trays, and then tamp them down to ensure an even surface with no pesky lumps and bumps.
A seed tamper is a piece of wood or stone that is used to compress and even out the surface of the soil or compost in a seed tray or seed bed.
Another essential learning that all experienced gardeners have when sowing seeds. How to water a seed tray without ruining your freshly sowed seeds!
You always water the seed tray or pot before sowing seeds.
You may think that watering should be done after sowing. Well, in most cases, this simply disturbs the seed, causes the soil to flow out and makes for very messy potting benches.
Save yourself the drama and water after tamping.
Give your seed trays either a soak in a sink or a good splash with a watering can. Ensure your watering can is fitted with a fine rose, so it doesn't ruin your neatly tampered seed tray. Let them drain for a minute, and then you're ready for sowing.
If you notice the soil is now unlevel at this stage, add some more seed compost, re-tamp and water again. (This may also alert you to the need for a better tamping method!)
I tend to classify seeds into two sizes, which dictate the potting method: fine seeds or large seeds. Each type of seed size has a different method for successfully sowing and growing from seed. With smaller seeds, you can germinate far more plants in a limited space, but they need potting on quickly.
With large seeds, it takes more space to sow fewer plants, but they require less potting and management.
Fine seeds are better sown on a seed tray and scattered lightly and evenly. If seeds are really tiny, like Begonias, then sometimes mixing them in fine sand can help distribute them evenly. Delicately tapping the packet to spread them is sometimes easier to get them out as they often stick to your hands.
Large seeds like sunflower, pumpkin and borage seeds can go individually into their own pots or modules. Choose the smallest pot possible, as you just want to get them to germinate. You can pot on all seedlings into larger pots as they progress. Don't plant large seeds in huge pots it is a waste of compost and space.
When it comes to sowing fine seeds in a greenhouse, here are my top tips for germination.
Another tip when sowing fine seeds is to take a look at the number of seeds in that packet. Sometimes there will be hundreds. Most seed packets give an average quantity, so you can plan.
Many new gardeners think one packet should fit in one tray, but you need to plan enough space incase all the seeds germinate. Sow no more than 50 seeds in any one seed tray.
If you need to split the packet amongst 2 or 3 trays instead to give them all room to breathe or save the remaining seeds for next year's growing.
Lightly scatter your seeds; use multiple trays rather than cram them all in
Once you have sown the seeds, most will need a light covering of either sieved seed compost or vermiculite. This helps the seeds contact the damp soil to start the fantastic biological growth process. This process sees the seed taking on water and bursting to life over the next week. It also means you can carefully water from above from now on, as the covering will protect the seeds from washing away.
Covering seeds with Vermiculite helps keep moisture in. It's also super light, making seed germination easier. This tray is only half covered for a demonstration of the light covering. Then, always label your seedlings so you know what you have grown and date them.
Egg boxes are a great recyclable seed tray alternative for new gardeners. They are smaller than normal seed trays, but the depth is ideal for new seeds. You also can use the other side, where the eggs have sat, as mini modules for when the seedlings are pricked out! Two for one!
Egg boxes are excellent cheap and cheerful seed trays; though they will require more watering due to the smaller volume of compost and the fact the sides absorb moisture.
Larger seeds, such as sunflower seeds or peas are classic examples, benefit from being in their own pots. Most large seeds require a deeper burial than fine seeds, but always check the seed's instructions for exceptions to this rule.
Here are my top tips and steps for sowing larger seeds:
Larger seeds usually spend longer in their initial pot before being transplanted out. The less disturbance to a new seedling, the better, as it allows the roots to grow out and help the plant put on rapid growth.
You still want to use smaller pots or modules, though, to save compost and space and reduce watering requirements. You can use plastic, as many gardeners do, but I plant in recycled containers where possible. This can also help you save considerable money if reusing household objects such as toilet rolls and egg boxes.
The process is similar to seed tray sowing. You still need to use decent seed compost, fill the pot, and tamp down. Water before you add your seed, as always, and then cover the seed in either sieved seed compost (so it is superfine) or vermiculite—label and place on your shelf or window sill.
Place your mini pots on an oven tray so you can help retain moisture and make moving them easier
Toilet rolls are a cheap way to either individually sow seeds or pot on seedlings from trays. Now, you may be looking at them saying, 'there is no bottom?'. Well, dear gardener, there is with a small amount of jiggery-pokery from you intrepid recycler. Simply fold one end in to create a bottom, as shown below. Then, you have your very own mini-seed plant pot.
Fold the bottoms in until you have a small pot. These toilet roll pots are ideal if you're on a budget or growing peas that can be transplanted out in their pots to biodegrade.
Now, this is the million-dollar question. People often contact me, panicking about their seeds after a week or so.
The time it takes for seeds to germinate can vary widely depending on the type of seed and the conditions in which it is planted. In general, seeds can take anywhere from a few days to several weeks to germinate.
Some fast-germinating seeds like lettuce, radishes, and beans can sprout within a week, while others like carrots, parsley, and peppers can take up to three weeks or more.
Seed germination depends on a number of things:
Germination can take anything from a couple of days to even months with some seeds.
Refer to the seed-sowing instructions and plant species guides you can easily find online.
Seeds in an unheated greenhouse will take longer to germinate than seeds inside on a window ledge, for example. Some seeds can take up to 80 days to germinate, like Astrantia major!
Some plants, like this beautiful Astrantia above, take their time to germinate.
Covering the seed trays and pots with a clear plastic bag will germinate quicker than without. However, you're introducing all sorts of non-recyclable plastic into your growing regime, which I'm not a fan of.
By sowing a variety of different species, you're bound to get some germinating before others. If you have followed the seed species instructions, please be patient. The worst thing you can do is start poking your fingers into the trays and pots.
Overwatering is also a big problem in seeds not germinating. Water when they start to dry out, don't keep flooding them with water.
As a matter of housekeeping, it's essential to mention the subject of garden hygiene. Keeping your pots clean and pathogen-free is essential when sowing seeds; all it takes is washing in clean, soapy water.
When growing plants or sowing seeds, the plant's health is determined in part by the environment in which it grows.
I advocate the heavy reuse of plastic trays or the use of more environmentally friendly trays such as wood or cardboard. Please give them a wash and dust them off before planting in them again. This quick bit of housekeeping will help ensure you're set for success.
If you wouldn't eat off it, then giving it a clean is a good rule of thumb!
Once you've sown your seeds, place them somewhere warm and light. Then water them sparingly so they don't dry out, but do not flood them. You'll get the knack, don't worry!
This is a frequently asked question by beginner and new gardeners eager to get seed sowing each year. New gardeners often see people on Social Media sowing seeds at random times of the year, and then all of a sudden, everyone gets a bit carried away with trying to follow suit.
While you can sow seeds at any time of year, the chances of the plants surviving if sown too early are slim. So, it is a waste of time sowing your vegetable seeds in December or January for the most part. It is simply too early, and they will struggle and need life support until spring when they can be planted out.
Most seed sowing starts in March when the weather starts to warm up, daylight is longer, and the garden is getting ready for new plants.
Other than that, you're good to now get cracking with growing your own from seed. Welcome, brave gardener, to a whole new obsession of growing from seed. I assure you that you are in for a delightful ride of unexpected developments and achievements.
I'd love to hear from you if you're sowing your own; send me your germination pictures on social media and ask any questions you may have.
Don't forget you can always visit my YouTube channel, where I’m happy to help. You can also check out my Tweet, Facebook or Instagram for more garden guides and tips.
Happy Seed Sowing!
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There’s nothing more rewarding than filling borders with plants, grown from little tiny seeds. As a beginner gardener, I’m amazed every time they germinate! I cant seem to grow echinacea though, any tips? Thanks! x