While you may be raring to go in the garden come New Year, this is still a fairly quiet time for growing. But some vegetables and flowers can be sown under glass, ready to fill out your garden as warmer days come back around in spring.
What to grow in January
Sowing seeds this early in the year takes patience and - often - a heated propagator. Light levels and the temperature are low and seedlings that come up at this point must be resilient to survive. Wondering what to plant in your greenhouse in January? Here’s our pick of the most reliable plants to sow in the first days of the year.
Growing vegetables in January
Onions
For large onions that are ready to harvest in late summer, sow exhibition varieties like ‘Ailsa Craig’ under glass now. This traditional favorite is easy to grow and ideal for adding to autumnal dishes in the kitchen. The only downside to larger onions is that they don’t store well, so put them to use before the end of the year. If you’d prefer smaller onions, wait to sow your seeds until March or April.
How to grow
Fill a tray with compost and sow seeds thinly on the top, covering them up with 5mm of seed compost. Keep them in a heated propagator or on a warm windowsill.
Care tips
When your onion seedlings are large enough to transplant, move them into 3-inch pots. In spring, plant them outside into finely raked soil, around 15cm apart.
When to harvest
Lift your onions from the ground from July onwards. Let them dry in the sunshine and hang them in a cool, airy place to store.
Chilies
If you have a heated propagator, add warmth to cold days by sowing chilies in January (if you don’t, sow them from March). There are hundreds of varieties to choose from, varying in color, heat and size. Chilies are easy to grow from seed and perfect for pots; keep them in your greenhouse or move them to a sunny balcony or patio once the plants are established.
How to grow
Fill individual pots with seed compost and sow 2-3 seeds in each. Cover them up with a little more compost or a sprinkling of vermiculite. Keep your chilies at 20-25°C and they should germinate within 10 days.
Care tips
Once your chilies’ true leaves appear, move the plants into larger individual pots. Keep potting them on as they grow. Feed them with a high potash fertilizer once a week, when they begin flowering.
When to harvest
As your chilies appear and change color, you can begin picking them as needed. Chilies can be used fresh or left to dry ready for storing.
Spinach
If you pick the right variety, you can sow spinach at any time of the year. And if you sow seeds each month, you’ll enjoy a never-ending, successional crop. Grow it through winter as a ‘cut and come again’ micro-green and enjoy multiple pickings, or let it mature to harvest larger leaves. Spinach thrives dotted between rows of other crops and is well-suited to life in a balcony pot or terrace container. High in antioxidants and nutrients, it can be savored in a fresh salad, steamed or wilted into soups, or added to curries and stews.
How to grow
Fill a container with light compost and water it before you start sowing, so the seeds don’t wash away. Sprinkle spinach seeds thinly over the top and cover them with a light layer of compost.
Care tips
Keep the soil moist and thin out seedlings as your spinach sprouts.
When to harvest
Spinach will be ready to pick as micro-greens within a month. For more mature leaves, let them grow for 6-10 weeks before harvesting.
Flowers to grow in January
Sweet peas
If you haven’t already done so, now’s the time to sow sweet peas. January sowings will reward you with a longer season of fragrant flowers. These cottage garden classics come in a range of tones, from white and pastel shades to deep purple, red and shocking pink.
How to grow
Soak your sweet pea seeds in water for a day before sowing. Fill long pots or root trainers with compost. Water them well and then add two seeds to each, covering them with an inch of compost. Keep them in a heated propagator or on a sunny windowsill and don’t water them again until they germinate. If you’re leaving them in the greenhouse, cover the pots with mesh to keep hungry mice at bay. Your seedlings should start to sprout within a couple of weeks.
Care tips
When your seedlings have their first few pairs of leaves, pinch out the tops to stop them from getting leggy. Pot them up before they get rootbound and plant them outdoors in spring, when the weather is milder.
When to harvest
January-sown sweet peas will start to flower from June. Pick them regularly, deadhead often and they’ll put on a show all summer long.
Geraniums
Also known as pelargoniums, geraniums are another old-fashioned favorite. Their flowers come in gaudy red, orange, pink and white and are often seen brightening up window boxes and hanging baskets, and adding a touch of class to greenhouses.
How to grow
Some varieties such as ‘Moulin Rouge’ and ‘Border Supreme’ can be sown in January in a heated propagator. Fill trays or pots with moist seed compost, sow seeds on top and cover them with a light sprinkle of compost or vermiculite. Keep them warm and ensure the compost stays moist. Your seedlings will germinate within 2-3 weeks
Care tips
When the seedlings are robust enough to handle, transplant them into 3-inch pots. After the last frost, harden them off (in a cold frame, if you have one) for a couple of weeks before planting out.
Rhino Greenhouse tips: Garden jobs in January
After your seeds are sown, use the slower January days to get on with other garden tasks:
- Prune apple and pear trees to keep them healthy and encourage new growth.
- Plant bare-root roses, shrubs and trees (so long as the ground isn’t frozen).
- Check any dahlia or begonia tubers you are storing. If they are starting to rot, move them to a drier place with more airflow.
- Tidy your greenhouse and shed ahead of spring, cleaning up pots and tools so they’re hygienic and ready to use when needed.
- Put out food and water for the birds, to help them survive the cold weather.
