If you want to know how to overwinter ferns, you can simplify the process into three steps. More than splitting ferns as part of maintenance and propagation, every gardener in the UK must learn the proper winter care for ferns. Remember that growing ferns is a year-round responsibility.
You can treat ferns as house plants and grow them indoors, but some UK gardeners have them in their gardens in the United Kingdom. Therefore, you must have a polytunnel to shelter these plants, especially when your location experiences harsh winters. Much like with overwintering other plants, it’s advantageous to have a polytunnel or year-round growing.
How To Overwinter Ferns For Success
Step #1. Preparation
Dormancy
The first step for overwintering ferns is to encourage them to enter dormancy. You can do this by withholding watering and fertilisation. Once you notice new shoots forming, you can resume these practices.
Acclimatisation
You also want to help them get acclimated to the new indoor location for the winter. The polytunnel or any sheltered area would be best for overwintering ferns in the UK. However, the emphasis is necessary to never immediately move the plants to the new location without gradually getting them used to the conditions.
Therefore, the best time to bring the ferns indoors is before the first frost to give them enough time to adjust. More so, it’s impossible to recover plants that froze. Gardeners in the UK often use the garage for acclimatisation before placing ferns indoors for the winter.
Plant arrangement
It would help if you also pruned the ferns, so only the new fronds will remain. This practice is necessary to prevent a mess from excessive growth when you bring them indoors. You don’t want to bring in any dead fronds.
Besides pruning, you also want to spray the plants to eliminate potential insects hiding in them. Check the underside of the leaves and inspect every part of the plant. More so, those who have potted ferns should repot them to a container one-third larger if they are rootbound to make watering easier later on.
Step #2. Know your fern
The next step for overwintering ferns is knowing the plants you have. Knowing your plants will enable you to understand the ideal practices for them during the winter months. You must check your varieties’ specific needs, but you can also classify ferns into evergreen and deciduous.
Evergreen ferns
For example, evergreen ferns typically grow in zones 3 to 19. Therefore, these plants will remain green in the winter, hence the name. The winter practice you can do for evergreen ferns includes maintaining soil moisture and trimming back the fronds they have grown.
Deciduous ferns
On the other hand, deciduous ferns are more likely to die back in the autumn because they don’t stay green in the winter. Therefore, you must cut back the dead fronds and place them somewhere warm during the winter. You can also mulch them for further protection against the harsh winter temperatures.
Overall, it’s worth noting that you can leave some ferns to dry up during the winter. With these species, you can let them naturally decompose, and they will still produce new fronds. You can then remove the dead fronds in the following spring because they will protect the crown anyway.
Step #3. Adjust accordingly
The final step in overwintering ferns is the adjustment of their new location. In general, you must keep the indoors warm but ensure that the ferns are not receiving direct light or heat. Remember that too much light or even a full sun will damage the plants and burn the foliage.
Another practice that you must do is checking their soil and prevent it from drying. However, be mindful not to overwater the plants to avoid diseases. Excessive overwatering is why you should not select an overly large container during repotting before overwintering.
Do you need to fertilise ferns? Ferns don’t have to feed during the winter months. However, you may need to cut back the dead fronds by the end of the season around a few inches of the crown.
How To Plant Ferns Outdoors
When can you place or plant the ferns outdoors after winter? You can resume outdoor growing after the danger of frost has passed. However, you must also ensure that the nighttime temperature is around 50°F before placing the plants outdoors to prevent problems.
You should be aware of the ideal growing conditions of the fern species you’re growing at this point. For example, do they prefer shade or some sun? Either way, choose an area with fertile and well-draining soil and maintain soil moisture.
Conclusion
The winter season in the UK doesn’t have to be a challenging time of the year for fern growers. Knowing how to overwinter ferns should help you keep these plants happy year-round. However, you must know your fern species’ specific conditions and requirements since some ferns should do well amidst the challenges in winter.
Otherwise, it would be best if you encouraged them to undergo dormancy. Prepare the plants by pruning and hosing them down before acclimating them gently indoors. It would help if you also repotted rootbound ferns before overwintering them.
Then, please place them in the polytunnel to protect them from extreme cold. You don’t need direct lights or heat as it can damage the ferns more. Maintain soil moisture, and you should be able to place the plants outdoors by spring after the danger of frost has passed.