Warmer days may still be some way off, but there are some vegetables that can be sown or planted in late winter, satisfying the gardener’s urge to get growing. Read on or view our video for five great ways to enjoy a super-early start to your gardening year…
1. Sow Direct Under Protection
Some crops can be direct-sown where they are to grow, if they’re offered some protection. Late winter is a great time to start once the ground isn't frozen, with day length increasing and temperatures creeping upwards on sunny days.
Cold frames and mini hoop tunnels can be used to start off the very hardiest vegetables, including radishes, winter lettuces and arugula. Cover the soil surface for at least one week before sowing to give the soil a chance to warm up and dry out a little, otherwise seeds will just rot rather than germinate.
2. Make Your Own Mini Greenhouses
Empty plastic bottles such as milk cartons can be repurposed to create miniature greenhouses ideal for cold-tolerant seedlings. Making a mini greenhouse is easy:
- Cut a bottle open two-thirds from the bottom, leaving a ‘hinge’ of plastic at the back.
- Pierce or drill drainage holes into the base.
- Fill with potting soil and sow your winter-hardy seeds.
- Cover the seeds over, and water.
- Close the lid by sealing the top of the bottle to the base with heavy-duty tape.
- Don’t forget to add a label with the variety and date of sowing.
These mini greenhouses can be placed straight outside once temperatures start to rise a little, saving valuable greenhouse or windowsill space. Leave them sealed up until early spring, when the seedlings will have germinated. When the seedlings push against the lid it’s time to open them out. Keep an eye on your seedlings and apply more water as needed in case sunny days dry them out.
Suitable seeds for sowing this way include winter-hardy salads such as endive, mâche or lamb’s lettuce and winter lettuce, or why not try close-planting cloves of garlic for flavorsome garlic shoots.
3. Sow in a Greenhouse or Tunnel
A number of early risers can be started off in a greenhouse or tunnel by sowing into seed trays, pots or cells. Hardy vegetables such as onions, shallots, chard and spinach fit the bill, and will grow slowly but steadily to produce sturdy young seedlings for planting out in a couple of months’ time.
Greenhouses offer the most flexible option for border or container-sown staples such as chard, beets, carrots, spinach, radish and cold-tolerant salads such as winter lettuce, mâche or endive.
Some seeds will benefit from gentle heat to encourage germination. Onions, for example, germinate best at 10-15ºC, or 50-60ºF. If you have an electricity supply in your greenhouse, place the sown seeds into a heated propagator until the seedlings emerge within around two weeks. Or you can use the next tip to start them inside...
4. Sow Indoors
Some crops will only germinate early if they receive the added warmth of an indoor windowsill or grow lights. Examples include spring-planted vegetables such as cauliflower, celery and cabbage, as well as heat-loving crops like peppers and eggplant.
Heat lovers are best started off in propagators or under growlights, which will also give strong light levels for good, even seedling growth. Sow them into pots or trays of seed-sowing potting soil. Grow lights can also be used to grow salads and herbs year-round - see our article and video on using grow lights for further details.
While starting off spring-planted crops, why not also grow some early pots of tasty leaves for your kitchen windowsill such as basil or a cut-and-come-again salad mix?
5. Early Onions and Shallots
Pots can be used to start off extra-early onions and shallots from miniature bulbs called sets. Fill three-inch (7cm) pots with potting soil. Push in one set per pot, leaving just the tip showing. Water well. Keep pots indoors on a bright windowsill, or inside a greenhouse or cold frame. You could also plant three or four sets to a larger container. If you are growing in a milder climate you can place these outside right away. The ones below are protected from cold winds by clear plastic sleeves cut from recycled bottles.
How Early to Sow?
Of course, late winter arrives at different times in different parts of the world. It's important not to sow too early indoors, otherwise the plants will be raring to go while the weather outside is still too cold to plant them out.
Our Garden Planner uses a network of thousands of local weather stations to find the last frost date for your area and calculates the precise sowing and planting dates for the crops in your plan, so by looking at your plan’s Plant List you’ll know exactly what you can sow when in your location. The blue bars in the Plant List show when you can start each crop indoors or under cover, and the green bars indicate the window of time when you can harden them off and gradually transfer them for planting outside.
As you can see, there’s great potential for early sowings. Let us know what you start off early in the season – drop a comment below and share your tips.