Sustainable Christmas: How to Grow Your Own Christmas Dinner

Plan now for a greener 2024

Sustainability

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As Christmas approaches, Santa isn’t the only one making a list. The nation’s thoughts turn to presents, parties, cards, decorations, and, of course, the dreaded supermarket dash to get the all-important Christmas dinner - and the trimmings - before the rush.

And while we are all aware of just how important it is to make small changes to become more sustainable the overconsumption of the festive period can make this easy to forget until New Year’s resolutions come around. However, our new research found that 61% of people in the UK said that they would like to try to have a more eco-friendly Christmas this year.

There are many things you can do to have a more sustainable Christmas, from using recyclable wrapping paper or eating yet another turkey sandwich to curb your food waste. But what about getting one step ahead for next Christmas now by giving growing your own vegetables at home a go throughout the year to prepare for extra delicious and sustainable festive seasons to come?


Your Ultimate Home-Grown Christmas Dinner Timeline

Dishing up a Christmas dinner is no small feat, and growing your own isn’t any smaller. Doing so requires patience: sowing for lots of the seeds happens in the early parts of the year to allow for a winter harvest. But growing your own food in your garden can be incredibly satisfying and fun for the whole family to do. Imagine now, sitting down with your family to enjoy a Christmas feast, knowing that all your veg is homegrown from your own efforts - what a great talking point!

Luckily most of the vegetables used in the traditional British Christmas dinner are easy to grow in the UK due to their hearty nature. However, research is key when growing your own vegetables and knowing when to seed, how to fertilise and when to harvest is essential for a fruitful crop.

While figuring out how to grow your vegetables at home can be a daunting task, it’s certainly a rewarding one! We’ve put together a helpful guide to give you an idea of your last chance to sow the seeds for each of your veggies, right through to the harvesting and storing period:

For more detailed information about how to grow each of the Christmas dinner vegetables displayed above, click here.



The Environmental Cost of Our Christmas Dinners

According to our analysis of the portion sizes offered in the UK’s most popular supermarkets, a standard Christmas dinner shopping for four (without any alcohol or cooking oils) emits around 23.75kg of CO2e - that’s before any of the cooking happens, just from the basic food items alone. For context, that’s roughly the carbon dioxide equivalent of driving a standard petrol car for 233 miles.



When looking at that over all the households in the UK who celebrate Christmas, that’s the equivalent of over a whopping 3.6 BILLION miles driven, or enough to go to the moon and back around 7,592 times (if you could drive there in a petrol car that is). Or enough to go to Uranus and back with a quick loop around the moon!

While growing your own vegetables might not save you a massive amount of money compared to buying them in store, it’s an excellent way to make more sustainable choices, pick up a new hobby, and push your budget and imagination even further.

By growing your own vegetables, you’re pretty much cutting your vegetable emissions to close to zero as home-grown food doesn’t need to be transported from the original source to the supermarket.

Of course, growing your own veggies is a time intensive feat that won’t fit into everyone’s lifestyles, but there are plenty of ways to help curb your emissions at Christmas time, such as:


  • Buying from your local farmer’s market.
  • Helping to curb food waste by buying veggies from services such as Oddbox, who sell fruit and veg that would’ve otherwise gone to waste.
  • You could also skip the turkey and give a fully veggie Christmas a go. Did someone say flexitarian festivities?

To view our methodology on how we reached these calculations, please click here.



The Step by Step Guide to Growing Each of Your Christmas Veggies to Perfection

Growing your own veggies is quite the craft, so we’ve listed out the steps from you from sowing your seeds, right through to cooking your Christmas greens.

Take a look at our step by step growing guide for each Christmas dinner vegetable and herb below, or visit Royal Horticultural Society for further expert details.


The vegetables

Potatoes

Prepare Seed Potatoes - Cut the seed potatoes into pieces, ensuring each piece has at least one ‘eye’ or bud. Allow the cut pieces to air dry for a day or two to prevent rotting.

Planting Potatoes - Plant the seed potato pieces about 3-4 inches deep in the soil in rows or mounds, spaced about 12-18 inches apart. Rows should be spaced 2-3 feet apart. Place the cut side down with the eye facing upward.

Hilling - As the potato plants grow and reach a height of 6-8 inches, begin to ‘hill’ them by gently mounding soil around the base of the plants. This helps protect the developing potatoes from sunlight, which can cause them to turn green.

Watering & fertilising - Keep the soil consistently moist but not waterlogged. Watering deeply once a week should be sufficient, but adjust based on your local climate and weather conditions.

Harvesting - Potatoes are ready for harvesting when the plants have flowered and started to die back. This typically occurs 12-14 weeks after planting. Most maincrop potatoes can be harvested between July and October.

Storing for Christmas Dinner - You can store your potatoes in a dry, cool and frost free place - such as the garage or shed once you’ve harvested. Potatoes are best stored reburied in coarse sand or soil until you need them for your Christmas feast.


Carrots

Selecting the Right Location - Carrots prefer full sun but can tolerate some shade. Ensure your chosen location has well-drained, loose, and sandy soil. Ideally, the soil pH should be between 6.0 and 6.8.

Planting Carrot Seeds - Carrot seeds are tiny, so take care when planting them. You can sow them directly in the garden at least 60 days before the first expected frost.

Watering and fertilising - Keep the soil consistently moist, especially during dry spells. Avoid overwatering, as it can lead to rotting. Avoid using nitrogen-rich fertilisers, as they can lead to excessive foliage growth and small roots.

Harvesting - Carrots are typically ready to harvest 12 to 16 weeks after planting, depending on the variety. You can start harvesting when they reach the desired size (usually 1/2 to 1 inch in diameter).

Storing for Christmas Dinner - Freshly harvested carrots can be frozen or stored in a dry place (similar to potatoes). Carrots can also be left in the ground over winter in some regions for a late winter or early spring harvest.


Brussel Sprouts

Seed Sowing - You can start the seeds indoors or directly sow them in the garden. For a Christmas harvest, start seeds indoors in early spring or sow them outdoors in late spring.

Transplanting - If you started the seeds indoors, you'll need to transplant the seedlings into the garden when they are a few inches tall and have a few true leaves. Transplanting is usually done in late spring or early summer.

Growing - They grow best in cool weather, so they are often planted for an autumn or winter harvest.

Caring for the Plants - Brussels sprout plants require regular care, including watering, mulching to retain moisture and control weeds, and fertilising as needed. It's also a good idea to stake or support the plants as they can become top-heavy with sprouts.

Harvesting - Brussels sprouts can be harvested once the small cabbage-like sprouts have formed along the stem. The sprouts will continue to develop from the bottom to the top of the plant, so you can harvest them over an extended period.

Storing for Christmas Dinner - Start seeds indoors in early spring for an autumn or winter harvest. The flavour of Brussels sprouts often improves after a light frost, so they are excellent for late autumn and winter harvests. Store fresh, unwashed in a plastic bag in the fridge for 3-5 weeks.


Parsnips

Seed Sowing - You can start parsnips from seeds, either directly sown in the garden or started indoors and transplanted later. Sow the seeds in early spring or late winter for a late spring or early summer harvest.

Growing - Once the seeds have germinated and the seedlings are established, they need several months to grow. Parsnips prefer cool weather, and they grow best in well-drained, deep, loose soil. They should be spaced adequately to allow room for the roots to develop.

Thinning - After the parsnip seedlings have sprouted and developed a few leaves, thin them out to provide enough space for the roots to grow properly. Space them at least 3-4 inches apart.

Harvesting - Parsnips can be harvested when they reach the desired size, typically between 2 to 4 inches in diameter and 12 to 18 inches in length.

Storing for Christmas Dinner - Once parsnip seeds are sown, you can enjoy a harvest throughout winter. The cool autumn and winter temperatures can enhance the flavour of parsnips. However, if you do need to store harvested parsnips on the lead up to Christmas, they can keep in the fridge for about 2 weeks, can be frozen or kept buried in sand or soil in a cool, dry place.


Broccoli

Seed Sowing - Broccoli is typically grown from seeds. You can start the seeds indoors or sow them directly in the garden.

Transplanting - When the broccoli seedlings have several leaves and are 4-6 inches tall, transplant them into the garden. Transplanting is usually done in early to mid-spring for a summer harvest or in late summer for a fall or winter harvest.

Growing - They prefer cool weather and can tolerate light frosts. Ensure they receive full sun and consistent moisture throughout their growth.

Caring for the Plants - Broccoli plants require regular care, including watering, mulching to retain moisture and control weeds, and fertilising as needed. They may also benefit from protection against pests like cabbage worms.

Harvesting - Broccoli heads are ready for harvest when the central head is firm and compact but not yet starting to flower. Cut the central head off with a sharp knife, leaving some of the stem attached. This encourages side shoots to develop, providing additional smaller heads for harvest.

Storing for Christmas Dinner - It's important to note that some broccoli varieties are more suited to autumn and winter growing, while others are better for spring and summer crops. Check the seed packet or plant label for information on the ideal growing season for the specific variety you choose. However, if you need to store harvested broccoli for your Christmas dinner, it’s best to freeze it after blanching.


Cauliflower

Growing - Cauliflower plants take approximately 60 to 100 days from transplanting to harvest, depending on the variety and growing conditions. Like broccoli, cauliflower plants prefer cool weather and can tolerate light frosts. Ensure they receive full sun and consistent moisture throughout their growth.

Harvesting - Cauliflower heads are ready for harvest when they are firm, dense, and the curds (the white part) are fully developed and still tightly closed. Harvest by cutting the head off at the base of the plant with a sharp knife.

Storing for Christmas Dinner - Once you’ve sown your seeds, you can enjoy cauliflower harvests throughout the autumn and winter season. The exact timing can vary based on your local climate and the specific variety you're growing. However, if you’ve harvested your cauliflower and need to store them, you can wrap unwashed cauliflower in a damp cloth or paper towel and keep in a perforated bag in the fridge. This will keep for 2-4 weeks, or you can freeze in florets for a longer store.


Green Peas

Growing - Green peas are a cool-season crop and thrive in cooler temperatures. They prefer well-drained, fertile soil and full sun to partial shade. Keep the soil consistently moist but not waterlogged. Mulching around the base of the pea plants can help conserve moisture and control weeds.

Harvesting - Green peas are ready for harvest when the pods are well-filled and the peas inside are plump. Harvest the pods by gently pulling them off the vine. For the best flavour and tenderness, pick peas regularly as soon as they are ready.

Storing for Christmas Dinner - Green peas can be harvested throughout July - October, and once picked, are best kept frozen in bags - just like how you would expect to freeze peas bought in freezer bags from the supermarket).



The Herbs

Sage

Location - Choose a sunny spot for your sage, as it prefers full sun. Sage can tolerate various soil types but prefers well-drained soil. It can also thrive in containers.

Planting - If planting sage in the garden, dig a hole that's slightly larger than the root ball of the plant and place the plant at the same level it was in its nursery container. Space sage plants about 2-3 feet apart, as they can grow into relatively large bushes. If you're growing sage in a container, choose a pot with good drainage. Sage can be grown from cuttings instead of seed for a quicker harvest.

Watering - Sage is drought-tolerant once established. Water newly planted sage regularly to help it establish roots, but once it's well-established, allow the soil to dry out between waterings.

Pruning - Pruning sage can help keep it bushy and encourage new growth. You can prune it lightly throughout the growing season and more significantly in the spring. .


Rosemary

Location - Choose a sunny spot for your rosemary, as it prefers full sun. Ensure that the soil is well-drained, as rosemary doesn't tolerate soggy conditions.

Planting - If you're planting rosemary outdoors, dig a hole that's slightly larger than the root ball of the plant and place the plant at the same level it was in its nursery container. Space rosemary plants about 2-3 feet apart, as they can grow into large bushes. Rosemary is usually grown from cuttings, as growing from seed can take several years.

Watering - Rosemary prefers to be kept on the drier side. Water it regularly but allow the soil to dry out between waterings. Be cautious not to overwater, as this can lead to root rot.

Pruning - Pruning rosemary can help it maintain a bushy shape and promote new growth. You can prune it lightly throughout the growing season and more heavily in the spring.


Thyme

Location - Choose a sunny spot for your thyme, as it prefers full sun. Thyme can tolerate various soil types but prefers well-drained soil with good airflow. It can also be grown in containers.

Planting - If planting thyme in the garden, space the plants about 12-24 inches apart, as they can spread and fill in over time. If growing in containers, choose a pot with good drainage. Thyme can be grown from cuttings instead of seed for a quicker harvest.

Watering - Thyme is drought-tolerant once established. Water newly planted thyme regularly to help it establish roots. Once it's established, allow the soil to dry out between waterings.

Pruning - Pruning thyme can help maintain a compact and bushy shape. You can prune it lightly throughout the growing season to encourage new growth.


Methodology


CO2e of each Christmas item

We created an itemised list of Christmas dinner essentials with some trimmings: potatoes, carrots, brussel sprouts, parsnips, broccoli, leeks, cauliflower, green peas, sage, rosemary, thyme, turkey, pigs in blankets, yorkshire puddings, gravy, cranberry sauce, christmas pudding, mince pies and double cream.

We then found the items as listed on a leading UK supermarket, alongside their recommended serving sizes, to ensure there was enough food for 4 servings of each of the listed items. We then used My Emissions footprint calculator to estimate the CO2e of each bought item. The following substitutions were made:

  • 240g packet of pigs in blankets - 120g cocktail sausages + 120g bacon
  • 230g packet of yorkshire puddings - 230g of bread
  • 200g jar of cranberry sauce - 200g cranberries
  • 400g christmas pudding - 400g chocolate cake
  • Packet of 6 mince pies (54g per pie) - 324g of fruit pies

Our assumptions were based on a family cooking mostly from scratch, without buying pre-prepared meat or pre-roasted veg.


CO2e miles equivalent per standard Christmas dinner food shop calculations

DfT 2023 CO2e statistics for a petrol car is 164g per km x 0.6214 (mile to km ratio) = 101.9096g per mile. Therefore 23,745g (CO2e of standard Christmas dinner food shop) ÷ 101.9096 (CO2e per mile on standard petrol car) = 233 miles.


CO2e miles equivalent of the entire Christmas celebrating population in the UK calculations

92% of consumers celebrate Christmas in the UK according to Statista. Based on 28.2 million households, this means roughly 25,944,000 households in the UK celebrate Christmas. 233 miles ÷ 4 = 58.25 miles per person. The average household in the UK has 2.4 people: 58.25 x 2.4 = 139.8 miles CO2e per household.

Therefore, 139.8 miles (CO2e equivalent per household of standard Christmas dinner food shop) x 25,944,000 = 3,626,971,200 approx equivalent miles for the entire nation.


Distance to the moon calculations

The moon is roughly 238,855 miles from Earth. Therefore, 3,626,971,200 (for the entire nation’s miles driven CO2e equivalent) ÷ 238,855 ÷ 2 = 7,592 times to the moon and back (7592.41).

Uranus is approximately 1.6 billion miles away from Earth.