How to Grow Cranberries

Cranberries, with their vibrant red hue and flavour, have captivated our taste buds and become a beloved addition to many foods and drinks. However, the journey from bush to table is an intricate one. In this article, you will find everything that you need to know about growing cranberries, how to grow cranberries from seed, as well as their soil requirements and suitable growing conditions for cranberries in the UK.

Details about cranberries

For you to get full, intuitive knowledge about the basics of how to grow cranberries, here is what you need to know:

• Botanical name: Vaccinium oxycoccos (USA); Vaccinium macrocarpon (EU).
• Origins: The common cranberry – Vaccinium oxycoccos – is often found in marshlands around northern and central Europe. The American variety – Vaccinium macrocarpon – is commonly cultivated.
• Founded: Captain Henry Hall founded the cranberry and was the first to sell them commercially around Massachusetts (1816).
• Varieties: Common cranberry varieties available in the UK are the ‘Early Black,’ ‘Pilgrim,’ ‘Redstar,’ and ‘Steven.’
• Effort to grow: Cranberries are relatively easy to grow. Since the plants have hardy properties, they require minimal attention, so long as they are grown in the right soil conditions.
• Planting location and conditions: Cranberries need moist, acidic, lime-free soil that has a pH level of 4.5. Add your cranberry plant to a sunny spot, or beside a garden pond or riverbed. They can grow well in pots too.
• Container-grown plants: The ‘Pilgrim’ and ‘Redstar’ variants of cranberries will work best when grown in containers or pots.
• Harvest: Your cranberry crops will prosper fruit within their third year. Harvest these in September and pick them before the first frost.
• Potential issues: Cranberries, although resistant to common pests and diseases, can still suffer from inadequate soil moisture or poor pH levels (either too acidic or too alkaline). Birds are another persistent problem and, therefore, use netting methods to protect the plants.
• Benefits: Growing cranberries will be exceptionally beneficial for your home foods. They are considered a superfood, due to their nutritional value and health benefits.
• Cranberries also have high disease-fighting antioxidants and outrank other fruits and veg including spinach and broccoli.
• Cranberries are commonly recognised for being a remedy for cystitis due to being anti-inflammatory, and will also prevent cardiovascular disease, strokes, and arthritis.
• Additionally, cranberries provide good cholesterol, will lower blood pressure, and are low in calories, sodium, and fat.

Potting History of Cranberries

If you are more interested in the background of cranberries, here is what we found out!

Native Americans incorporated cranberries into their diet and medicinal practices, consuming them in various forms such as fresh, ground, mashed, baked into bread, and even steeped in tea made from the leaves. They also combined cranberries with deer meat to create ‘pemmican[i],’ a vital survival food relied upon by fur traders during the harsh winter months.

When the European settlers found cranberries, it was the Native Americans who introduced these vibrant fruits to them. Fascinated by the flower’s resemblance to the head, neck, and bill of a crane, the settlers initially named them crane-berries. An intriguing historical event occurred in 1667 when New Englanders presented ten barrels of cranberries as part of a gift to King Charles II in a gesture of goodwill.

Cranberries’ significant vitamin C content made them a natural remedy for scurvy, leading to their inclusion in barrels stored aboard American sailing ships to maintain the crew’s health. The cranberry’s prominence in American culture was further solidified in 1796 when they were served at the inaugural celebration of the Pilgrims’ landing. Since then, cranberry sauce has become an enduring centrepiece of the traditional Thanksgiving dinner.

Why Grow Cranberries?

To ensure that your garden remains vibrant all-year round, all you need is a versatile cranberry plant. Its lush green foliage undergoes a breath-taking transformation during the autumn months, decorating the landscape with bright colours, including yellow and red.

When summer arrives, delicate pink colours will grace the plant, giving way to the glossy red berries that are inseparable for the holiday season. Cranberry sauce has become an integral part of the traditional Christmas turkey dinner, while the berries themselves bring a festive burst of colour to wreaths and natural table adornments, enhancing the overall ambience.

The fascination behind cranberries extends beyond their seasonal association. These remarkable fruits possess an impressive shelf life, lasting for weeks in the refrigerator. Furthermore, their freezer-friendly nature allows for year-round enjoyment, as they can be added to delicatessens including cakes, biscuits, and muffins, for an extra, tangy and fruity flavour. Bursting with essential vitamins and nutrients, these plump and succulent berries offer a wholesome and nourishing addition to your culinary efforts, ensuring not only delectable flavours but also a boost to your well-being.

Growing Conditions for Cranberries

To ensure successful cranberry cultivation, we recommend that you consider the following factors. When learning how to grow cranberries in the US, they thrive within USDA Zones 4 to 7, and need a cold winter period of approximately three months, with roughly 1,000 to 2,500 hours at temperatures between 32°F and 45°F.

Cranberries need full sun exposure to grow, although you should monitor your chosen location in case it gets too hot, especially in south-facing positions.

For cranberries to flourish, they need well-drained, humus-rich soil with a preference for moist conditions. While sandy or peaty marshland is preferrable, these versatile plants can adapt to ordinary acidic soil when ample aged compost or organic matter is added. Use aged compost or shredded leaf mulch in the winter to protect the plants from frost.

Acidic soil plays a crucial role when learning how to grow cranberries, with an ideal pH range of 4.0 to 5.5. Creating a raised bed or sunken bed offers better control over soil acidity and drainage, providing an optimal growing environment. While cranberries cannot tolerate dry soil, they exhibit resilience against cold weather flooding, highlighting their adaptability and endurance.

By taking these considerations into account, you can foster a thriving cranberry crop in your garden. If learning how to grow cranberries in a polytunnel, we have several polytunnel layout ideas to accommodate the growth of fruitful crops such as cranberries.

How to Grow Your Own Cranberry Bush

Cranberry bushes bring a remarkable combination of resilience, minimal susceptibility to pests, and a captivating display of both fruit and ornamental charm throughout the seasons. These versatile shrubs effortlessly adapt to various conditions and require minimal upkeep. They exist in two primary forms, each possessing unique characteristics.

The first type comprises upright bushes, characterised by sturdy, woody stems, lobed deep green leaves reminiscent of maple leaves, and clusters of bell-shaped, pink-flushed white flowers that create a delicate and lacy appearance.

The second variety consists of trailing counterparts, with slender, wiry stems that spread through underground runners. These trailing shrubs boast smaller oval-shaped deep green leaves, forming a bushy habit, accompanied by flat creamy-white flowers that eventually give way to splendid autumnal berries. Both forms of cranberry shrubs grace the landscape with an exquisite array of autumn foliage, showcasing a magnificent palette of yellow, crimson, purple, and burgundy hues.

Cranberry Varieties

So, which varieties of cranberry are the best to be grown in your garden or polytunnel? As mentioned earlier, there are over 100 varieties of cranberry, but which ones will provide the best results?

One variety of cranberry that we recommend for knowing how to grow cranberries is the cranberry pilgrim[ii]. Not only does it sprout pink flowers in the spring with its popular red berries in the winter which are also beneficial for wildlife, but they can be added to your homemade foods too, from pies, jam, and of course, cranberry sauce[iii].

Alternatively, you could also try the ‘Early Black[iv].’ These cranberries are a lot darker and are usually a reddish-purple in tone. The berries produced are medium-sized and will be ready for harvesting before other varieties.

Thirdly, there is the ‘Franklin[v],’ whose properties are similar to ‘Early Black’ and ‘Howes.’ It is also compact and is suitable for containers.

Cranberry Pollination

Cranberry pollination is a fascinating process that ensures the formation of their beloved red berries. As cranberries are not self-pollinating, they rely on external factors to facilitate successful pollination. The flowers, with their delicate beauty, require the assistance of bees and other pollinators to transfer pollen between the male and female reproductive structures. These pollinators are attracted to the nectar and showy appearance of cranberry flowers.

Weather conditions play a vital role in cranberry pollination, as cool temperatures and low wind speed are optimal for efficient pollinator activity. To ensure abundant pollination, cranberry growers often introduce honeybee colonies to their fields during the flowering period.

To ensure your cranberry plants are pollinated correctly, ensure to:

• Space cranberry plants 1-2 feet apart.
• Doing this will allow the crops to accommodate an appropriate 1 foot of length and width without clashing with other crops. If stem roots touch the ground, this will allow them to grow larger.

Are you interested in taking up a new hobby? Try out our beekeeping for beginners guide.

Planting Advice for Cranberries

As mentioned, cranberries thrive in acidic soil and prefer to be grown in full sun or partial shade, in a moist but not waterlogged environment. While some commercial growers may cover cranberry plants with a shallow layer of water for harvesting convenience, it’s important to note that this doesn’t represent the ideal growing conditions.

To cultivate cranberries, you should plant them with peat or moss, incorporating organic matter and ericaceous compost if your soil lacks acidity. Raised beds can be a suitable option for alkaline, clay soil, or silt soils, using a mix of organic matter, sand, and ericaceous compost. After planting, mulching with acidic materials like pine needles, leaf mould, or conifer clippings helps maintain the desired soil ph.

Although cranberries are self-fertile, planting multiple varieties can enhance pollination and increase fruit production. Allow ample spacing of 90cm-1.2m (3-4ft) between plants to accommodate their spreading nature (closer spacing of 60cm or 2ft is suitable for upright varieties forming dense hedges).

When growing cranberries in containers, use ericaceous compost and consider adding water-retaining gel to ensure proper moisture retention around the roots. While cranberry bushes can withstand cold and exposed sites, it’s important to note that fruit production may be affected in such conditions.

To ensure the prosperous growth of your cranberries, consider the following:

1. Plant your cranberry crops in autumn when frosts are rare, or alternatively, in spring where the danger of frost has passed. Avoid planting them in hot and dry weather.
2. Prepare your planting bed by mixing acidic peat into soil before planting.
3. Optional: use an old bathtub or watering trough, line the bed with ceramic tiling, and fill with an acidic potting mixture.
4. Dig a hole half the size of the root ball, but twice as wide. Moisten the hole before planting. Allow the soil mark to be level with the planting hole.
5. Plant cuttings in 12-18 inches. You can also mix bone meal into the soil before settling in the new plants.
6. Fill the hole with half native soil or organic planting mixture. Pat the soil firmly to prevent air pockets.
7. Water the plant with a liquid fertiliser.
8. Keep the soil moist until the plant begins to grow.

Further tips on growing cranberries

Keep the area surrounding your cranberry crops well-weeded, especially during the first year of growth. Cranberries do not cope against weeds, so ensure these are removed also.

Add 5-10cm (2-4 inches) of organic mulch around the base of the cranberry bush every November to protect against the frost, which will also keep the soil moist and reach the appropriate acidity.

Water regularly during dry spells using collected rainwater to improve stability and eco-friendly methods in your garden. If growing in a polytunnel, there are various environmental benefits of a domestic polytunnel. Maintaining a balance of multipurpose feeding throughout the year will enable fresh growth.

Cranberries are also loved by many birds and mammals. To combat this, introduce netting methods around your crops at the beginning of the fruiting season to prevent losing them. We recommend our tape thread shade and windbreak netting methods for your cranberries to prosper. Vine weevils[vi] can be a common pest problem for cranberries, so ensure to use nematodes (small worms that kill vine weevils) which will protect the plants.

Cranberries will only grow within the top 6 inches of soil; ensure to keep this moist when following this how to grow cranberries guide.

Container Growing Cranberries

As mentioned, certain variants of cranberries will benefit from being container grown. If you would prefer this option, you can:

• Add to a container that is around 12-18 inches in width, and 8 inches deep (roots will grow 4-6 inches deep).
• Fill the container with acidic potting and coarse. Introduce lime-free grit to accommodate drainage.
• Place the pot in a saucer levelled out with water so that the soil will not dry out.

How to Water Cranberries

Because cranberries prefer to be grown in marshlands, they therefore need plentiful amounts of water if grown from a garden with no nearby pond. To do this, follow the tips below:

• If using tap water, be aware that this can be quite alkaline. Instead, collect rainwater or filtered water which will have more of a neutral pH level.
• Add a dressing of grit or sand to the top level of the bedding to retain moisture and block out weed growth.
• Mix in a fish emulsion fertiliser (ratio of 2-4-2), perfect for cranberries.
• Renew the mulch or other added soil features periodically. TIP: Mix mulch with sawdust.

How to Prune Cranberries

When growing cranberries, they do not have to be pruned regularly. Instead, we recommend that you prune or trim the bush in the spring and remove runners to keep them more compact. Adding pruning methods to the plants will also help to avoid overcrowding.

Cut away any sprawling stems and any upright stems, just enough to allow more room for growth. Of course, remove dead or damaged stems, too, by removing a few inches of runner tips; this will encourage more fruit-bearing stems.

Learn to Propagate Cranberries from Seeds

You should propagate cranberry plants when the stem cuttings are root ready. If growing them from seeds, it can take 3-5 years for fruits to be produced. Place cranberries in a fridge to allow the seeds to be coldly stratified 3 months before sowing.

Grow these seeds in a pot size of 3-4 inches. Two seeds can also be potted in each pot around ¼ inches deep.

Seeds will germinate the quickest at a temperature of 21°C / 70°F and will germinate in 3-5 weeks. Seedlings can be grown at a temperature of 15-23°C / 60-75°F.

Do not remove the top four to five leaves as well as any flower buds. Instead, dip the cut end into the powdered rooting hormone. Place a cutting of 4 inches deep into a medium-sized pot and in a warm spot to aid rooting. Cuttings of 18-inch centres can be added to peaty soil with an inch cutting above ground level.

In the case of mild winters, add the rooted cutting outdoors in the autumn; set out in early spring.

Harvesting and storing cranberries

When harvesting and storing cranberries, here is what you need to consider.

Begin harvesting when the berries have reached their full deep red colour, typically during the autumn. NOTE: pink or white berries are not yet ripe, as only red fruits will be ready for picking.

Commercial growers commonly employ a wet harvest approach, flooding the fields with 6 to 8 inches of water. This submerges the plants, causing the ripe fruit to float to the surface for easy collection. In-home gardens do not need to flood planting beds.

Once cranberries have ripened, they can remain on the bush for a month or two, if freezing temperatures are not imminent. It is recommended to pick the berries as needed to ensure their freshness. Freezing temperatures can damage the berries, so it’s important to complete the harvest before such conditions occur.

Due to their tartness, raw cranberries are not typically consumed as is. Instead, they are commonly sweetened and used in various preparations such as juices, jellies, muffins, and cranberry sauce, enhancing both flavour and versatility.

For storage, cranberries can be kept in the refrigerator for approximately two to three months. To maintain their freshness, store them in an airtight plastic bag or container. Alternatively, cranberries can be frozen, allowing for longer-term storage and future use.

Kitchen Uses for Cranberries

When applying cranberries to the kitchen, there are a few things to keep in mind:

• They can be added to jams, jellies, sauces, juices, and other condiments.
• Fresh cranberries can be kept for 3 weeks. DO NOT freeze them.
• Dehydrated cranberries can be used as snacks, or added to cereals, oatmeal, or summer salads.

Controlling Cranberry Pests and Diseases

When it comes to the health of cranberry plants, being aware of potential pests and diseases is crucial. Here are some key points to consider:

• Yellowing leaves: this can be a sign of chlorosis, which can be caused by lime-induced conditions. In this case, the leaves exhibit yellowing at the edges, with the yellowing gradually spreading between the veins that remain green. Apply chelated iron to the plant to prevent this from getting worse.
• Cranberry fruit worms: these pose a threat to the fruits, as they bore into them and consume the seeds before exiting. These are the larvae of the Sparganothis moth[vii]. To control them, use pheromone lures which are effective in trapping the adult moths.
• Spotted fire worm: This is another larva of the same moth. These fire worms feed on the fruit, potentially causing damage. Again, use pheromone lures to block out the moths.
• False blossom: This is a viral disease that is spread by leafhoppers. It is important to control these insects, as they serve as vectors for the disease. Once a cranberry plant is infected with the virus, it cannot be saved.

Grow Your Own Fruitful Cranberry Crops Now

In conclusion, learning how to grow cranberries requires specific cultivating needs, as shown in this article, but will be very beneficial for your home and the fruits that sprout will be very rewarding, following your hard efforts. By following these guidelines, you can successfully cultivate cranberries, adding vibrancy to your garden and culinary creations. Start learning how to grow cranberries now!

FAQs

Sources

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[i] Marks, M. (n.d.). How to Make Pemmican. Mark’s Daily Apple. Retrieved from: https://www.marksdailyapple.com/how-to-make-pemmican/ [accessed 12/06/23]

[ii] Jackson’s Nurseries. (n.d.). Cranberry ‘Pilgrim’. Jackson’s Nurseries. Retrieved from: https://www.jacksonsnurseries.co.uk/cranberry-pilgrim.html [accessed 12/06/23]

[iii] BBC Good Food. (n.d.). Really Simple Cranberry Sauce. BBC Good Food. Retrieved from: https://www.bbcgoodfood.com/recipes/really-simple-cranberry-sauce [accessed 12/06/23]

[iv] Victorian Nursery. (n.d.). Cranberry ‘Early Black’. Victorian Nursery. Retrieved from: https://www.victoriananursery.co.uk/Cranberry-Early-Black/ [accessed 12/06/23]

[v] Chris Bowers & Sons. (n.d.). Cranberries ‘Franklin’. Chris Bowers & Sons. Retrieved from: https://www.chrisbowers.co.uk/product/cranberries-franklin/ [accessed 12/06/23]

[vi] Which? Gardening. (n.d.). Vine weevil. Which? Gardening. Retrieved from: https://gardening.which.co.uk/hc/en-gb/articles/214012605-Vine-weevil [accessed 12/06/23]

[vii] UKMoths. (n.d.). Sparganothis pilleriana. UKMoths. Retrieved from: https://ukmoths.org.uk/species/sparganothis-pilleriana/ [accessed 12/06/23]