Sowing seeds is an activity that brings joy and smiles all round to established gardeners. Each year gardeners and allotment holders around the country eagerly sow seeds of both flowers and vegetables to grow on in their gardeners. Sowing seeds are really cost-effective and offer gardeners an insane variety of plants that you simply can't buy from garden centres. If you are new to sowing seeds and want to get cracking with growing your own then this how to sow seeds guide is for you!

It’s amazing to think that most of the plants in your garden can be grown from tiny unassuming seeds. These little pods of life allow plants to propagate themselves and spread joy with us gardeners wanting to grow our own. The beauty of sowing seeds is the sheer variety of plants that you will have at your disposal. You’re not stuck with whatever trend your garden centre is pushing. You can break free, like that tiny seed embryo, and create your own personalised gardens just for you. How brilliant!

Now 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 guide on how to sow seeds is going to show you how to can sow, grow and succeed with seeds. There’s a tongue twister!

Choosing the right seed sowing compost

The first step before you rip open your seed packets is to select the right growing medium. As much as it is possible to grow seedlings in that 3-year-old half-empty dried out bag of compost behind your shed, I would urge you to think twice. If you’re taking the time to sow, nurture and then pot on your seeds the right seed mix is the essential first step. It can also help you dodge some of the issues when using the wrong soil. Dampening off, mildew, disease or funky smells from your seed trays can all be avoided. I’m using Dalefoot Seed compost, completely natural and a mix of sheep’s wool and bracken.

I’m using Dalefoot Seed Compost 100% Natural and made of Bracken and Wool

Seed trays and pot selection

Many new gardeners tend to use the wrong pots when sowing seeds. By sowing seedlings in deep large pots in the belief that all this extra room and compost is beneficial to the seed. Whilst your intentions are noble, all you’re going to do is waste compost and take up vast amounts of precious greenhouse or windowsill space.

Seed trays are relatively shallow trays were seeds can be sown efficiently over a larger surface area. The majority of commercially available seeds need the following to germinate.

  • Moisture
  • Warmth (some need extreme spells of warmth and cold)
  • Light (some seeds need the absence of light)
  • Airflow (both for roots and to prevent disease during germination)

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!

Now plastic trays are probably the cheapest and most widely used form of 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 then 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!

Filling and tamping your seed trays

Fill your seed trays with quality seed compost using your hands, a bucket, a sweet scoop or empty pot. Whatever floats your boat, the same with whether you want to wear gloves to protect your gel acrylics or get all mother earth and go hands free!

Fill the tray just below the top and 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. Which 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 its level and you can pick it up and down easily then it will be fine.

Fill your seed trays and them tamp them down to ensure an even surface with no pesky lumps and bumps

Watering seed trays before you sow

This is another not so obvious but essential learning that all experienced gardeners will champion. 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 good for sowing.

If you notice the soils now unlevel at this stage then add some more seed compost, re-tamp and water again. (This may also alert you to the need for a better tamping method!)

Fine Seeds vs Large Seeds

I tend to class seeds into two sizes which dictates the potting method. Fine seeds are better sown on a seed tray and scattered lightly and evenly. Larger seeds, like sunflower, pumpkin and borage seeds can go individually into their own pots or modules. Again choose the smallest pot possible as you’re just wanting to get them to germinate. You can pot on all seedlings into larger pots as they progress.

If seeds are really tiny like Begonias then sometimes mixing them in fine sand can help distribute them evenly. Sometimes just delicately tapping the packet to spread them is easier and less fussy.

How to Sow Fine Seeds

You’re wanting to scatter fine seeds evenly and sparingly across your seed tray. Have a look at the number of seeds in that packet. Many new gardeners think that one packet should fit in one tray but you need to plan that most of those seeds may actually germinate. Plan for success people! If you need to split the packet amongst 2 or 3 trays instead to give them all room to breathe.

How to sow seeds in a seed tray
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 make contact with the damp soil to start the amazing biological growth process. This process sees the seed taking on water and bursting to life over the next week or so. It also means you can water, carefully, 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.

Egg boxes are a great recyclable seed tray alternative which new gardeners can use. Yes 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 fact the sides absorb moisture.

Sowing larger seeds in individual pots

Larger seeds such as sunflower seeds or peas as a classic example benefit from being in their own pots. Most large seeds require a deeper burial than fine seed, always check the seeds instructions though for exceptions to this rule. 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 than normal pots or modules though to save compost, 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 a decent seed compost, fill the pot and then 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 Roll Pots for Seeds

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

How long does it take for seeds to germinate?

Now, this is the million dollar question. People often get in touch with me panicking about their seeds after a week or so. It really depends on a number of things:

  • Temperature
  • Moisture levels
  • Humidity
  • Seed / Plant Species
  • Pot Luck

Germination can take anything from a couple of days to even months with some seeds. Always 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!

Somethings, like these beautiful Astrantia, take their time to germinate

If you cover the seed trays and pots with a clear plastic bag they 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 then please try to 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.

Clean your pots & trays

As a matter of housekeeping its important to mention the awkward subject of garden personal hygiene. When growing plants or sowing seeds the health of the plant is determined in part by the environment in which it grows. I advocate heavily the reuse of plastic trays or using more environmentally friendly trays such as wood or card. Please give them a wash and dust 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 give 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 not flood them. You’ll get the knack dont worry!

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 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 TweetFacebook or Instagram for more garden guides and tips.

Happy Seed Sowing!

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  1. […] are a patient group. After sowing seeds you need to wait and let mother nature take over. Constantly tapping your toes, staring longingly […]

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