How to successfully sow seeds

If there’s one thing well worth doing in these dark times it is sowing some seeds. We’re seeing so many people doing it metaphorically in terms of kindness and love (the more of that the better!), but this is the perfect time to do it with most plant seeds, too.

It is so satisfying to watch something that starts as little more than a dry husk then grow – thanks to you – into glorious, healthy plants, bringing joy and welcome distraction.

Choose your seeds well and for just a few quid you could have hundreds of plants by midsummer covered with bees and butterflies, bringing life to your gardens, balconies and roof gardens. With online stores still open (at the time of writing), there is chance to buy now and get sowing.

However, growing plants from seeds can be seen as something of a dark art. Let’s bust that myth – I don’t consider myself to have ‘green fingers’, but I’ve grown thousands of plants over the years and most of the plants in my garden are from seed. All you need is to follow some golden rules.

So, I headed out early this morning to sow a load of seeds and show you the steps I follow that will greatly improve your chances of success (first of all in brief, and then if you’d like a longer read I explain each in more detail further down the blog). Plus I suggest some of my top choices for seeds to try:

Sowing indoors: golden rules

1. Use fresh seed

2. If you can, use fresh compost (make sure it is peat-free, of course).

3. Fill a seed tray or pot with the compost (sieved if possible). Lightly compress it.

4. Sit it in a tray of tap water to let the water soak up into the compost from below until the surface is glistening.

5. Sow the seed thinly. Cover it only to the depth of the seed with a light covering of compost or horticultural grit. (A few seeds need to be treated differently, so always read the packet).

6. Label clearly.

7. Put in a warm, light place but not in direct sunlight.

8. Check them daily – TLC will be rewarded! Keep the compost moist but definitely not waterlogged.

9. Once the seeds have germinated (some will do so quickly; some will keep you waiting until you have given up hope and then amaze you) and have at least two true leaves (not the first two ‘seed leaves’), transplant them (‘pot them on’) into separate pots.

10. Plant out in the garden only once they are robust, healthy plants.

Oh, and I have one important secret to impart. They won't all work! Even for the professionals, they don't all germinate. Just celebrate the successes rather than worrying about the mis-hits.

Sowing outdoors

Here is one of my previous blogs about how to plant and grow beds of annual flowers from seed outside, which can be just as thrilling.

What seeds to sow?

Here are my top tips for plants that are easy to grow from seed right now and should give you colour by summer. All the choices below are excellent for various types of bee; butterflies are more picky, so I’ve marked those that are likely to be used by butterflies for nectar.

• Agastache
• Anchusa
• Beans (broad beans, runner beans)
• Betony
• Bird's-foot trefoil (foodplant of the Common Blue butterfly)
• Borage
• Cardoon
• Chives
• Coneflower – butterflies
• Cosmos
• Dame's violet
• Fennel
• Honeywort
• Knapweed – butterflies
• Rudbeckia
• Salvias
• Scabious – butterflies
• Scorpion weed (Phacelia tanacetifolia) – often sold in large packs as a ‘green manure’, so especially cheap
• Sunflowers – plus of course they will ultimately provide seeds for the birds
• Tithonia - butterflies
• Verbena bonariensis – butterflies
• Viper's bugloss Echium 'Blue bedder'

If growing with children, then sunflowers are my top choice – kids will love seeing how fast these grow, and it can become a competition as the season progresses. But definitely don’t plant your seedlings outside too early or slugs and snails are likely to get them.

Adrian's award-winning RSPB Gardening for Wildlife has a whole section on his top 500 plants for wildlife, all with photos, to help you choose.

Other wildlife-friendly activities you might like to do in the garden this spring:

Here are links to some of my previous blogs to give you more ideas:

Creating a border for bees

Adding nesting boxes to your garden

Letting parts of your lawn grow to create a pop-up meadow

Using a trail cam to see what is visiting at night

Adding a birdbath

Making a small pond

And of course there are plenty of activities to try that I wrote for our Giving Nature a Home webpages here.

And here’s my ‘long read’ to successful seed sowing:

1. Use fresh seed. Few seeds are likely to germinate from old packets that have been sat in the cupboard for years. I keep my seeds fresh by storing them in the cool of the salad draw of the fridge.
2. If you can, use fresh compost (make sure it is peat-free, of course). Garden soil is typically full of pathogens and weed seeds. All peat-free composts I’ve used in the last couple of years have been perfectly adequate, but I personally recommend Dalefoot Composts made from peat and wool, the New Horizon I'm using here today, and composts by Melcourt.
3. Fill a freshly-washed, clean seed tray or pot with your peat-free compost. Those sterile conditions are important to limit the risk of fungal infection. I use my plastic plant trays that I have had for years, taking care so they can be used again and again. If you don’t have any old plant trays or pots, you could buy coir pots for a non-plastic option. When preparing the compost, use a garden sieve if you can to remove any large pieces – seeds like to grow in fine crumbs rather than among lumps! For an even better seed compost, mix it 50:50 with perlite or vermiculite. Lightly compress the compost, but don’t ram it hard.
4. Sit the seed tray in a bowl of tap water to let the water soak up into the compost until the surface is glistening. Rainwater carries too many fungal and algae spores. If you water from above, it can oversoak the soil.
5. Sow the seed thinly. Too dense and you risk what is called ‘damping off’, a fungal disease that makes seedlings keel over. Cover the seeds only to the depth of the seed with a light dusting of sieved compost or with horticultural grit; very fine seeds shouldn’t be covered at all. A very few seed types need light to germinate, but most will cope with a light dusting over the top. I like to sow them in rows. Tip some seeds into the palm of your hand and then large seeds can usually be picked out one by one; smaller seeds can be lifted using the wet end of a pencil; very fine seeds will probably need to be sprinkled. A few seeds need to be sown on the surface and not covered, and a few others needs to be put in a bag of moist compost in the fridge for 3–4 weeks – they will only germinate after they’ve had a shiver (it’s called stratification).
6. Label clearly. You can use wooden lollipop sticks rather than having to use plastic, or cut strips from old plastic milk cartons, and of course if you have old plastic plant labels use them again and again.
7. Put in a warm, light place but not in direct sunlight, which is likely to scorch-dry the seeds and kill them off as they germinate. Covering the seeds with a propagator lid or sheet of glass/Perspex will usually help, keeping humidity high, but you must remove any cover the moment germination starts or you will risk all the seedlings damping off.
8. Look in on your trays a couple of times each day – this is a critical time, and diligence will pay off at this stage. Keep the compost moist but not waterlogged, and take care if watering from above to use a very fine rose on the watering can so as to not dislodge seeds or flatten seedlings.
9. Once the seeds have germinated, transplant them (‘pot them on’) into separate pots but only once they have two true leaves at least. The first two leaves you will see are called seed leaves, so you need to wait until there is another pair of leaves – the true leaves – above that. Hold the seedlings by a leaf tip, not the stem which is very vulnerable to bruising at this stage.
10. Plant out in the garden only once they are robust, healthy plants. If you plant out when still little seedlings, they are an instant salad for slugs and snails.