The time has come to start planting out seeds. There is a whisper in the air of spring. The days are lighter and there are flowers starting to bloom again. I always feel a special kind of excitement. Planting seeds is possibly my most favourite thing in the world to do. I can get lost for hours and days in my own dialogue with these miracles of potential. Dreaming in to being their beauty.
Here in Cornwall, it has been a very slow, damp start to these changes but this step-by-step guide will get you going so when the weather changes your seedlings will be ready to go into your garden.
Seed Starting Indoors: A Complete Step-by-Step Guide
Cultivating your own plants from seeds indoors is a rewarding experience! This guide
will take you through everything you need to know, from gathering supplies to
transplanting your happy seedlings outside.
Step 1: Gather Your Supplies
• Seeds: By now you have chosen and purchased the seed varieties you wish
to grow. If you haven’t – get shopping! Choose from reputable organic seed
companies. Check seed packets for specific planting information.
•Planting Containers: Seed starting trays with drainage holes are ideal. You
can also upcycle containers like egg cartons or yogurt cups, but ensure
drainage.
•Seed Starting Mix: This lightweight, well-draining mix is crucial for
germination. I use a mix of organic compost and add a few handfuls of
vermiculite or perlite especially for the very fine seeds.
• Water Source: A mister is helpful or a fine watering can nozzle.
• Light Source: Seedlings need plenty of light! All my sunny windowsills are
chocka block with trays. A greenhouse or polytunnel is great of course.
• Plant labels – I use wooden ice cream sticks or reuse plastic plant labels
each season. Or cut plastic strips from waste containers and have a marking
pen available.
• Optional: Heat mat - promotes germination, especially seeds that need a
warm soil to germinate like chillies, tomatoes and peppers. A Humidity dome
traps the moisture and heat.
Step 2: Prepare Your Planting Trays
1. Mix the seed starting mix together. 10 parts compost to 1 part vermiculite or
perlite or both. Pour it into your containers, leaving about ½ inch of space at
the top.
2. Tamp down the mix gently to create a smooth surface.
3. Water well and leave to drain.
Step 3: Sow the Seeds
• Refer to seed packet instructions for planting depth and spacing
recommendations.
• For tiny seeds, you can sow them directly on the surface and gently press
them in. Sprinkle a little vermiculite just to cover them.
• Larger seeds might need a shallow hole made by pressing in to create a hole.
Cover as high as the length of the seed – no more or they struggle to find the
light.
Step 4: Label Your Seeds
Use plant labels to mark the type of seed and planting date. This will help you
identify seedlings later.
Step 5: Keep Your Seeds Moist and Warm (Germination Stage)
•Water gently using a mister or the bottom watering method (placing the tray in
a shallow dish of water until the mix is moist). Avoid overwatering.
• Cover the trays with a humidity dome or plastic wrap to retain moisture.
• Place the trays in a warm location.
Step 6: Light Up Their Lives (Seedling Stage)
• Once seeds germinate, usually within 1-2 weeks depending on the seed
variety. You can then move the seedlings to a slightly cooler location but they
still need to be protected, warm and have good light.
Step 7: Moving Day (Thinning and Transplanting)
• Once seedlings have developed their first set of true leaves (not the initial
seed leaves), it's time to thin.
• Gently remove weaker seedlings, leaving only the strongest ones.
• When seedlings have several sets of true leaves and their roots reach the
bottom of the container, they're ready to transplant into larger pots.
Step 8: Harden Off Your Seedlings
• Gradually introduce your seedlings to outdoor conditions before transplanting
them permanently.
• Take them outside for short periods in shaded areas, gradually increasing the
duration and sun exposure.
• This hardening-off process helps seedlings adapt to the harsher outdoor
environment.
Step 9: Transplanting Outdoors
• Wait until the danger of frost has passed and soil temperatures are warm
enough for your specific plants (refer to seed packet instructions).
• Choose a suitable location in your garden with proper sun and soil
requirements.
• Carefully remove seedlings from their pots and transplant them into the
prepared soil.
• Water them thoroughly and continue to care for them according to their
needs.
Congratulations! You've successfully nurtured your seeds from tiny beginnings into
healthy seedlings ready to flourish outdoors. With a little care and attention, you'll be
enjoying the fruits and vegetables of your labour in no time.