Seed Sowing
Growing your own plants from seed is exciting, rewarding and represents good value for money if you are successful at it. Firstly choose the seeds you would like to grow and take note of the suggested sowing dates on the back of the packet and the number of seeds in each packet. You can sow up to 200 seeds to a half sized standard seed tray (17×22 cms). If the seed count is a lot less than this you could use a small pot as your seed tray.
Half fill with a good quality seed compost such as Levington Seed and Cutting compost and then mix in the same quantity of Perlite. Perlite is a naturally occurring volcanic rock that ensures your compost is very free draining, will fall apart easily when you come to move your seedlings on and ensures a high level of oxygen in the compost to assist in healthy root growth. Level off and lightly firm. Then water well using mains water. Your water butt water contains too much algae and fungal spores which would be very detrimental to seedling growth. Dust the surface with Copper Mixture to help prevent any fungal attacks on the emerging seedlings. Now sow your seeds onto the surface as evenly as you can. Then cover with a thin layer of Vermiculite.
This is also a natural silica rock that is heated to a high temperature to force the layers to separate. Water is held between these layers keeping the seeds nicely moist. The Vermiculite will never stick together, as compost often does, ensuring even germination. Water again using mains water once more. Now cover with a sheet of polythene, this could be cling film, and a single sheet of newspaper and place in a warm, light spot, ideally a propagator in a heated greenhouse, conservatory or south or west facing windowsill.
The polythene ensures no moisture is lost whilst the seeds germinate and the paper lets enough light through to ensure germination takes place but that strong sunshine will not scorch the emerging seedlings. As soon as the seedlings are nicely germinated remove the polythene and you will now need to check regularly for watering. Once they are big enough to handle you can move them on into another tray or pot. If you are sowing very fine seeds such as Petunia or Lobelia do not cover with Vermiculite but cover with polythene and paper as described above.
If you like the thought of getting a few more Dahlia plants from the Dahlia tubers you are buying now, try the following tip. On getting your Dahlias home plant into shallow trays or pots using a good quality compost such as Jacks Magic. Keep them in a frost free, well lit position, ideally a heated greenhouse or conservatory.
After a few weeks they will begin to produce new shoots. Once these are about 3 inches (8cms) long cut the top 1.5 inches (4cms) off using a sharp knife. Dip the base of these cuttings into Vitax Rooting Powder and insert into pots or seed trays filled with a 50:50 mixture by volume of Levington Seed and Cutting compost and Perlite. Water well using mains water, cover as above and put into a propagator again in a well lit, warm position. Leave for approximately 3 weeks when if you pull gently on a leaf the plant should now be firmly anchored with its new roots.
You can then transfer to some larger pots. The original tubers will produce more shoots and can be planted out once the danger of frosts has passed.