It’s good to see the seedlings of flowers have arrived at garden centres. If you are not very good at growing flowers from seeds this is an ideal opportunity.
The seeds have been sown by someone else. They have had to keep them warm and cope with damping off disease and now they are ready for us to grow at home.
The greenhouse temperature simply needs to be warm enough to keep the frost out. A little heater is a good idea and in a greenhouse without electricity a paraffin heater is suitable.
If there is electricity in the greenhouse an electric heater with a thermostat is ideal because the thermostat will keep the temperature at the level you choose.
Two types of compost are available for pricking out seedlings. The first is John Innes No1. This used to be ideal, but from years of experience and judging from your letters, it is a good idea to add 10 per cent additional sharp sand, mixed well before use.
The second is loamless compost and there are at least 10 different brands. The more expensive ones are best. The cheap ones are best used for top dressings in the garden.
Traditionally, seedlings were pricked out in rows in seed trays – five across and eight lengthwise, 40 to a tray. But there are better ideas.
Use a seed tray and buy insert cells using the 24-cell units which fit a standard tray. You’ll find these at the garden centre. Once you’ve used them you’ll never return to the old way of growing too many in a tray.
Fill the cells with loamless compost. Use a piece of wood to level the surface. Prick out one seedling to each cell using a dibber and hold the seedling by the leaf. If the stems are handled the seedlings often collapse.
Lobelia seedlings are pricked out in groups of two or three. There are different colours available as seedlings. If you like mixed colours see if you can find lobelia String of Pearls. These are bushy and trailing.
Water the seedlings with tap water. Butt water may contain bad bacteria but is fine for mature plants. Put the trays in the greenhouse and cover with a sheet of newspaper. This keeps them cosy and out of direct sunshine.
If you follow my advice and use insert cells you will produce wonderful plants with individual roots. All will be bushy and strong and all will be the same good quality. This is because they have plenty of space and are not competing for light.
Looking back to when 40 plants were grown in a tray, the ones on the outside edges were good, but those in the centre were tall and weak. We used to plant two plants in the place of one in the flower beds and quite often both died.
If you think this week’s article is basic I agree, but I wrote it because so many of you ask about growing seedlings for the first time.
TIP OF THE WEEK
If you enjoyed hyacinths indoors and the flowers are now fading, keep the compost moist.
When the flowers have turned brown, remove all the dead blooms but leave the green stems. Plant the whole group in the garden straight away.
Don’t wait until the leaves die back. If you do this without breaking up the roots, the bulbs will naturalise.