growing plants from seed
It can be rewarding and cost effective to grow plants from seed. What to sow is down to personal preference. From growing apple and lemon trees from seeds as children, to growing annuals for summer and autumn colour pockets to enhance mature gardens, with a bit of patience and work most plants can be grown at home from seed.
When to sow depends on the plant, and there are often two possible growing times, either sowing in the autumn or the spring. The weather in your part of the the world will be a factor, but most seeds you buy will have good advice on the back of the packet.
Many gardeners will have their own variations in the sowing method, but here's a step by step process that works for us.
Sowing the seeds
1. Pick a pot and sort the drainage
Seed trays can be a bit more awkward to work with, as root growth may get a bit lateral rather than downward if they aren't very deep, and when it then comes to separating the germinated plants this can make things difficult. So we like to use a decent sized pot, and put grit in the bottom 20% or so to make sure it drains well.
2. (Over)Fill with compost
When growing form seed look for an open compost that doesn't clump. We'd suggest John Innes Potting Composts as a good starting point. No.1 for annuals and biennials, No.2 for perennials, and No.3 for shrubs and trees. Loosely overfill the pot, and don't worry about excess above the rim.
3. Tap down and Strike OFF
Settle the compost by giving the pot a good tap down on a hard surface, and level off any excess by pushing in off level with the rim, either by hand or with a flat tool.
4. Tamper down
Use a suitable implement, ideally a wooden pot tamper, to press, or tamper, the soil down to give a level base to sow on.
5. Sow the seeds
Move the pot away from the rest of the compost so that rogue seeds don't find their way into it. Then scatter the seeds over the compost. How many and how dense will depend on the seed. Of course, you could sow seeds in individual pots, but it takes up a lot more space.
Some seeds, particularly larger, harder seeds might need soaked beforehand. Again, read the label or look up info on the seed. If it is one that needs soaked, adding a small bit of washing up liquid to the water can help mimic the effects of a bird or animals stomach, and help with germination. Very importantly, don't forget to label the pot or you might forget what's coming!
6. Cover with compost
Use a sieve to cover the seeds with compost. Don't use too fine a sieve or only the smallest particles will get through, and you might end up creating a dam on top of the seeds that water can't penetrate. How much compost on top will depend on the seeds to some part, so again read the label.
7. Protect with grit
If the pot is going outside, consider topping with some grit to protect the compost and seeds. This time, sieve the grit to remove the dust and fine particles which could cause a dam effect, and then use the bigger grit on top of the pot.
Where to put the pot, and how much light, warmth and water the seeds require for germination will depend on the species. When watering be sure to use the rose on the watering can as it doesn't take much force to damage young seedlings. Some patience might be required, but stick with your seeds and they should get there!
It depends on the variety, but most seedlings will need potting on, and will end up as healthier, stronger plants. Here a few steps to help you get it right.
1-4. Preparing the pot
When the seeds have germinated and the seedlings are big enough, repeat steps 1-4 above to prepare enough pots for your seedlings.
5. Pricking out
Gently ease all the seedlings and compost from their original pot. Separate the seedlings by pricking them out from each other, taking care not to damage the roots.
6. Planting on
Make a hole big enough for the roots, and set the seedling in the hole, slightly lower than it first grew, as this will strengthen the stem and make for a more successful plant.
7. Hardening off
Harden plants off gradually, so that seedlings become accustomed to strong sunlight, cool nights and less-frequent watering. This usually takes about one to two weeks. Start with a couple of hours of sun in a sheltered location. Protect the seedlings from strong sun, wind, hard rain and cool temperatures.
8. Planting outside
Once the plant is ready, plant outside in the garden, and enjoy your handiwork!