Maybe you were thinking there aren’t that many vegetables to plant in December? Well, you’d be amazed how many crops benefit from winter sowing, whether to make the most of the extra weeks on the plot or under glass, or to improve the flavor or vitality of the veggies you grow. Super-hot chillies use the extra time to develop tongue-tingling fruits – whilst kales develop tender-tasting leaves in the cool, crisp air. Even on the shortest day (21st December), there are planting traditions attached to growing garlic that can help ensure the tastiest returns at harvest time.
Unheated greenhouses and cold frames give you the perfect setting for maintaining balance, ventilation and protection for fledgling plants. For those crops that are a little bit more vulnerable to the cold, heated propagators can help with germination and early seedling health. You can also make more of the light with the help of grow lamps – and even grow some crops without any light at all. This is such an exciting time as we look ahead to the new vegetable planting calendar year, the longer days and the future gardening possibilities.
We’ve compiled the must-grow veggies you need to focus on during the winter weeks. From pink oyster mushrooms and red hot chilli peppers to undercover treats that provide quick nourishment and variety, our round-up of vegetables to grow will keep you stocked up in winter warmers for months to come.
12 vegetables to plant in December for months of tasty and nutritious treats
If you’re keen to kickstart another year of healthy, tasty crop-growing in the best possible way, a few early sowings and plantings will put you in a very strong position for when spring arrives. From gargantuan garlic to teensy clumps of cress, there’s plenty here to please your palates.
Enjoyable and inventive kitchen garden ideas such as sea kale and pink oyster mushrooms can be found even when daylight seems low. And if natural light seems non-existent, you can always grab some chicory and find out how easy it is to cultivate exotic chicons! Whether you’re after quick croppers, bulky bulbs or interesting new colors in the coming months, this must-grow guide for December planting is sure to inspire.
1. Red kale
When it comes to hearty crops that deliver in all weathers, they don’t come more resilient than kale. These kick-ass cabbage cousins are some of the best low maintenance plants you can grow. Revered as an ornamental superfood, kale is packed with minerals like calcium, folates, and vitamins A, C and K. As well as being amongst the best winter brassicas you can harvest, it is a surprisingly adaptable crop to start off in the latter stages of winter. Red kale is ideal both as mature plants that crop into autumn, and as baby leaves to harvest five weeks from sowing. So for cool pickings that benefit from crisp freshness at both ends of the year, make kale one of your key vegetables to plant in December.
Varieties such as ‘Red Russian’, ‘Redbor’ and ‘Scarlet’ make for tender cold-hardy mini crops as well as enduring garden staples. Leave them to bulk up in cool and shady garden displays, and they will reward you with a glut of luscious leaves come harvest time. Many varieties have been bred for high levels of disease resistance, as well as tolerance to weather extremes. What’s more, if they are exposed to chills, it can improve the taste. As Amateur Gardening’s veg expert Lucy Chamberlain notes, the only thing these plants need if grown to full size is some space. ‘If you intend to grow plants to maturity, grow them 24in (60cm) apart each way. Plant at greater density if you plan to grow outside,’ says Lucy.
Knowing how to grow kale doesn’t involve much ongoing care beyond watering and weeding. When harvesting the leaves, Lucy recommends working from the base up and keeping the central rosette intact for the most prolific crops. Great companion plants for kale include tomatoes, garlic, chives, leeks and tagetes.
- Buy ‘Redbor’ kale in the US: view at Super Seeds (opens in new tab)
- Buy ‘Redbor’ kale in the UK: view at Thompson & Morgan (opens in new tab)
Lucy was a Horticultural Advisor at RHS Wisley for six years. She has been Head Gardener on a 100-acre private Essex estate for seven years, and writes regularly for titles such as The Garden, Gardeners’ World and The Guardian. She's the author of the RHS Step by Step Veg Patch book, and the fruit and vegetable expert for Amateur Gardening magazine, providing readers with invaluable grow-your-own-advice in every issue.
2. Edible dill
Delicate, feathery and evocative of aniseed balls, dill is mistakenly believed to be tricky to cultivate. This couldn’t be further from the truth, and the slow, sleepy pace of winter is the perfect time to indulge in early sowings. Packed with antioxidants, magnesium and vitamins, and believed to help reduce cholesterol and the risk of heart disease, dill is often overlooked in favor of the staples like basil and parsley. However, if you want to create a herb garden with real scope, it is well worth squeezing into your winter gardening routine.
When making December planting of dill undercover, you just need to make sure you choose a suitable propagation zone with regulated light and warmth. If you can find a space in your greenhouse, all you need to factor in are a couple of heated propagators and heat mats if you want to grow dill ahead of the pack. While dill is cold-hardy, it germinates best where soil temperatures are kept at around 65˚F. Make sure your developing dill receives at least six hours of sunlight a day and keep the soil slightly acidic, well drained and, above all, moist (not soggy).
As seedlings develop, you can pot dill on in a garden planter alongside rocket, cilantro and chervil. Plant out only once the last risk of frost has passed, or keep indoors. Harvest from eight weeks after sowing, and don’t be afraid of pinching the tips as this can promote bushier growth. Allow a couple to flower, and you can also enjoy the seeds. Try compact ‘Fernleaf’ and dwarf ‘Bouquet’ for containers, and ‘Mammoth’ if you have space and fancy something with more decorative potential.
- Buy ‘Mammoth’ dill in the US: view at Burpee (opens in new tab)
- Buy 'Mammoth' dill in the UK: view at Amazon (opens in new tab)
3. Super-hot chillies
Some of the most critical vegetables to plant in December are those super-hot chillies designed to get your taste-buds a-tingling. As Chris Bonnett of Gardening Express (opens in new tab) points out, very hot chillies grow slowly. They need warmth and humidity – and plenty of it – to ripen fully. So the sooner you start off those Carolina Reaper, Trinidad Scorpion and Naga peppers, the better. As anyone who grows chillies will know, indoor sowing is the best way of moderating the conditions these plants crave early on. Starting in December guarantees that those eventual fruits have plenty of time to acquire the atomic levels of heat required.
For clarity, it is the Capsicum chinense varieties that benefit most from these earlier sowings to bring about the most bountiful harvests. (For comparison, C. annuum varieties are best sown a little later.)
‘To get the best results, sow seeds in multi-purpose or seed compost. Keep plants in a heated propagator (set to 77˚F/25˚C or higher) under a growing light until seedlings appear,’ says Chris. Chilli enthusiasts are advised to kickstart their fiery campaigns by growing vegetables in pots and keeping those emerging seedlings as warm as possible with a heated mat or similar. Water just enough to keep the surface of the compost moist and prevent chills below the surface level. Once plants are 6in (15cm) high, you can pot them on.
They can also be planted up in borders and grown in tandem with rosemary, oregano, nasturtiums, dill, parsley, basil, chives, beans and peas. Once they fruit, water sparingly and expose to more sun for crops that really feel the burn. Super-hot chillies reward a long season of care, warmth and a light seaweed feed with unforgettably vibrant fruits that pack a real punch.
- Buy Habanero chillies in the US: view at Burpee (opens in new tab)
- Buy Habanero chillies in the UK: view at Suttons (opens in new tab)
4. Wild rocket
Snappy, peppery and resilient, if there’s one leafy plant guaranteed to be the life and soul of the salad bar this winter, it’s wild rocket (arugula). As a cut-and-come-again cropper, it has a short life but makes the most of it and crams in a belly-full of flavor. Our recommendation for December planting is ‘Dragon’s Tongue’, a feisty purple and green rocket that grows well in winter and is loaded with potassium and vitamin C.
If you are looking for something simple to plant in a greenhouse and you want quick returns to keep you fed in these chilly days, wild rocket delivers – and it doesn’t skimp on heat! Sow batches in an unheated greenhouse or a cloche every two weeks, or keep on a windowsill for bursts of continuous growth. You can grow rocket and other herbs together in pots, and also plant in tandem with spinach, mizuna and mustards. Growing in shallow containers allows you to cultivate clumps in successive harvests, picking a few leaves from each plant when needed.
Fans of companion planting can try growing with onions, chives and garlic, which can all help to intensify the taste. Younger leaves are milder and more delicate, while older leaves will be hotter. You can also eat flower buds and shoots, but pinching them out will prolong cropping.
- Buy rocket in the US: view at Burpee (opens in new tab)
- Buy rocket in the UK: view at Amazon (opens in new tab)
5. Elephant garlic
Also called wild leek (Allium ampeloprasum), this garlic develops gargantuan bulbs. As Chris Bonnett notes, if soil is moist and free draining, these chunky croppers appreciate a winter planting. Plant in situ, giving each one an 8in (20cm) space on all sides – or start under a cold frame.
Big on character but gentle on the tongue, elephant garlic is unfussy about wet winters – as long as you avoid waterlogging. If your soil holds water, add sand to the planting hole and top with fine compost to assist with drainage and keep your elephants happy. Garlic benefits from this period of dormancy, and traditionally gardeners are encouraged to plant on the shortest day of the year (21 December). And for those who are short on space and looking for small vegetable garden ideas, garlic can even be planted in large tubs or buckets.
The planted clove swells to a monobulb, but plant now for a long season and this will split into more. This garlic grows flower spikes that reach 1.5m tall. When learning how to grow garlic, one good cultivation tip is to eat the stems (scapes) so energy is directed towards developing the bulbs, then lift in June. And don't forget about including companion plants for garlic in your plot – some potatoes and brassicas will help improve the health of your crops and increase your yield.
- Buy garlic in the US: view at Amazon (opens in new tab)
- Buy garlic in the UK: view at Crocus (opens in new tab)
6. Potted mint
If you’re after something as varied as it is fast-growing, make some room in your December planting for ‘fruity’ mints. Because mint is one of the best herbs to grow in your garden, you may think it is best in an open space. Yes, mint is a robust, prolific perennial with a reputation for taking over – but at this time of year, you can keep things well contained if you grow mint in good-sized pots kept under glass. Crinkly sweet Moroccan mint (Mentha spicata var. crispa), crispy apple mint (M. suaveolens) and aromatic strawberry mint (M. x piperita) are well suited to container growing, and their hardy, fuzzy-haired leaves make them ideal for winter growing.
As Chris Bonnett explains, mint is perfect for growing in the chilly winter months. You can enjoy the freshest, most fragrant leaves if you have room undercover in a bright, partially shaded greenhouse or mini greenhouse or a light windowsill. Even the most vigorous mints can be kept in check if you use a large pot, tub or a bucket (with holes).
‘Place the plant in a spot that’s in partial shade and keep the soil moist but well-drained,’ says Chris. More established potted mints work well with other container-kept herb garden ideas such as curly parsley and spicy oregano. If contained well, it’s also an ideal companion for carrot and kale as it can deter common pests.
As well as growing from seed, you can also cultivate new mint plants at this time of year by taking root cuttings. This is a quick and easy way of hedging your bets. Cut sections of roots into 1.5in (4cm) lengths, place on gritty compost, cover and water well. Leave in a frost-free spot under glass and then, in spring, grow the young cuttings in their own pots.
- Buy apple mint in the US: view at Trade Winds Fruit (opens in new tab)
- Buy apple mint in the UK: view at Crocus (opens in new tab)
7. Chicory and chicons
This entry into our top vegetables to grow in December offers a generous two-for-one offer! Grow chicory to eat over the coming weeks as a quick leafy treat – or let it develop in the ground and then make a delicacy known as ‘chicons’. Leaving the plant to build up a long tap root, you use that root in December to sprout torpedo-shaped chicons using a technique known as ‘forcing’. Intrigued? You should be!
Sown on heat mats under glass, varieties such as ‘Palla Rossa’ and ‘Sugar Loaf’ make a snappy, flavorsome cut-and-come-again option. As Lucy Chamberlain points out: ‘Just give them ample light by placing them on a bright windowsill or on greenhouse staging.’ These are some of the easiest vegetables to grow in winter. But if you’re feeling like developing a variety for forcing over winter, we recommend ‘Witloof’ or ‘Witloof Zoom’.
Grown in raised garden beds in warmer months, the thick tap roots that develop can be forced the following December. Cover with a forcing jar or bucket, or place roots in sandy compost in large pots and leave in a dark place. This coaxes them into early growth, resulting in chicons; a crisp, creamy delicacy that can be enjoyed raw with citrus fruits or braised in white wine and thyme.
- Buy chicory in the US: view at Burpee (opens in new tab)
- Buy Witloof chicory in the UK: view at Amazon (opens in new tab)