Indoor Vegetable Sowing
If you have access to a heated greenhouse or a cool conservatory, or even a bright windowsill in a cool room, then there are quite a few things that can be sown throughout this month in trays/modules/pots for planting out later.
- Onion (seed)
- Shallot (seed)
- Summer cauliflower
- Summer cabbage
- Sprouting broccoli (Summer varieties)
- Brussels sprouts (some varieties)
- Kohl rabi
- Jerusalem artichoke
- Broad bean
- Pea and mangetout
- Most commonly grown herbs
Once the seeds have germinated, move the seedlings to a bright, cool frost-free location, such as an unheated greenhouse or cold-frame.
The following vegetables can also be sown this month but, being less hardy, have slightly more demanding care requirements:
- Chilli pepper
- Sweet pepper
These will need to be germinated in a heated room – around 21-24°C (70-75°F). The temperature for the resulting seedlings should, if possible, be kept above 15°C (59°F), i.e. a cool well-lit room or heated greenhouse. Sweet pepper and melon seedlings benefit from higher temperatures – around 20°C (68°F).
Outdoor Vegetable Sowing
Hardy enough to be started outdoors most years are:
- Onion sets
- Shallot sets
- Broad bean
But don’t be in a rush to sow outdoors. The most important factor is soil temperature, with all but the hardiest of vegetables needing a minimum soil temperature of 7ºC to germinate. A good guide is the rate at which weed seeds are germinating on your prepared beds. There will come a point – typically in the first week of April on the sandy soils of Leith, but in late March during a mild winter – when the weeds appear all over the bed and start romping away. This is the time to get sowing.
In a mild year where the ground is workable, or on a pre-warmed bed, you can try the following towards the end of this month:
- Summer sprouting broccoli
- Cauliflower (some varieties of)
- Brussels sprouts (some varieties of)
- Spring onion
There’s still time to buy seed potatoes if you haven’t done so already, but you’ll need to do it sooner rather than later. Set them to “chit” somewhere bright and cool, such as an unheated spare room in the house or a shed with a window.
Indoor Flower Sowing
There are few flower seeds that can be sown outdoors at the moment, as the soil is too cold. However, the period from the beginning if February to the end of March is a good time to sow half-hardy annuals, some hardy annuals and many hardy perennials indoors (in a heated greenhouse or a cool conservatory, or on a bright windowsill in a cool room).
Examples of half-hardy annuals that can be sown now are:
- Tagetes (marigold)
- Brachyscome (swan river daisy)
- Ipomoea (morning glory)
- Impatiens (busy lizzie)
- Dorotheanthus (livingstone daisy)
- Scarlet sage
Most half-hardy annuals need a little extra heat to germinate – typically 18-24°C (65-75°F). They will, therefore, need to be germinated in a heated room. Move them to a cooler, brighter and frost-free location once they have germinated.
If you are not able to sow half-hardy annuals this month then all is not lost; sowing from seed is the most cost effective but not the only way to grow these plants. In a month or two most of the above will be available in garden centres and supermarkets as trays of bedding plants.
Hardy annuals that benefit from an extended growing season (e.g. sweetpea, sunflower, canary creeper) can be started off indoors but, on the whole, hardy annuals work much better sown directly where they are to grow.
Many perennials grown from seed can be sown now (any time from late Winter to early Summer in fact). Sow as soon as possible however if you want the plants to flower in the first year.
(Examples include silene, delphinium, echinacea, coreopsis, aubretia, aquilegia)
Outdoor Flower Sowing
As with outdoor sowing of vegetables, the soil needs to be warm enough, and this won’t become the case until sometime between the end of this month and the first half of next. For more details of sowing hardy annuals direct, see April Tips.
If you need any further advice about what to grow and how do grow it, or if there’s anything above that needs further explanation, then please feel free to contact me at: firstname.lastname@example.org