How to Grow Ferns: Everything You Need To Know
If you have always wanted to know how to grow ferns, you will find you will find all the information you need in this latest blog.
Perfect for amateur gardeners, ferns are easy to grow, and they love a shady spot with soil that isn’t too dry. Depending on your local climate, there will be ferns that will suit all your planting schemes.
For example, Cinnamon ferns (Osmundastrum cinnamomeum) are winter-hardy ferns that can tolerate winters in Zone 3-9 (USDA). In contrast, ferns like the Boston fern (Nephrolepsis exaltata), also known as the sword fern, don’t do well in the cold and only thrive in Zones 9-11 (USDA).
Additionally, ferns have vibrant fronds in various sizes, shapes, and textures. Their versatile appearance and requirements make ferns perfect for any style of garden.
Read on to find out how to successfully grow healthy and beautiful ferns.
How to Grow Ferns From Spores
Mature, fully-grown ferns reproduce when they produce spores, meaning you can also grow ferns from spores.
However, growing ferns this way will require patience, as growing ferns from spores is a slow process. It could take a year or more for your ferns to germinate. Despite the long wait, growing ferns are more straightforward than you might have initially thought.
Below, we reveal how to grow ferns from spores in a simple step-by-step guide.
1. Preparing Your Container
Fern seedlings are incredibly vulnerable to contaminants like fungi, moss, and mold. For that reason, it’s essential that you sterilize everything before you start.
Collect your containers (you can use a plastic pot or plastic box, provided they have drainage holes). Sterilize your chosen containers and tools with boiling water, allowing them to cool completely before use.
Alternatively, you can sanitize your containers using a mixture of one-part bleach and nine parts water. All you need to do is let your pots soak in the solution for 10 minutes and rinse them thoroughly with clean water.
Please note that you should wear gloves and an apron if bleach is used to sanitize your containers.
2. Sanitizing The Soil
Ferns thrive in soil rich in organic matter, such as garden compost. Most fern varieties also prefer neutral to alkaline soil. However, some varieties, like the Table Mountain Tree Fern (Blechnum tabulare), like acidic conditions.
Ultimately, you should choose a soil that suits the specific requirements of your chosen fern variety.
To sanitize your soil, you can use boiling water to thoroughly soak the compost.
Alternatively, mix your compost with water, place it in an open plastic sandwich bag, and microwave it for a few minutes. When the bag steams up, seal it. Leave for a few minutes as the steam will sterilize the soil. If you’re looking for an eco-friendly composting solution, consider using a Lomi composter.
Whichever method you use, it’s best to let your potting mix cool down to room temperature.
Once your potting mix is at room temperature, pour it into your container and smooth over the soil’s surface.
3. Collecting Your Spores
You will find the fern’s spore cases on the undersides of their fronds. They typically look like small bumps and appear in rows. Often green at first, these spore cases turn brown or black with maturity.
To collect spores, place a mature fern frond (frond is the term for a fern leaf) on a white piece of paper. By using white paper, you’ll find it easier to see the ripened, brown dust (the spores) that fall from the fern’s frond.
Leave the frond for a few days until you notice spores on the paper.
4. Planting Your Spores
We suggest you carefully fold the paper in half lengthwise, allowing the spores to fall into the crease. This will make it easier to distribute the spores evenly on top of the potting mix.
Once folded, you can use the paper to sprinkle spores over the surface of the potting mix sparsely.
After spreading the spores evenly around the potting mix’s surface, do not cover them with soil. Your spores need light to germinate.
5. Positioning Your Spores
Place your containers inside sealable plastic bags or cover them with clear plastic lids. This will ensure the spores are in humid conditions.
Keep the containers in a reasonably well-lit spot with no direct sun – ferns prefer indirect light.
Ensure the spores stay moist, but take care not to waterlog them. From here, all you have to do is wait. After several weeks or months, your spores will begin to sprout.
Keep your sprouting spores humid until they are large enough to transplant into larger pots.
Tip: You can generally tell your ferns are ready to transplant when they have at least three fronds.
Growing Ferns Outdoors: How to Plant Outdoor Ferns
If you aren’t a fan of growing ferns via spores, there are other methods of growing ferns. You might prefer to grow ferns outdoors in your garden.
Growing ferns outdoors in hanging baskets or as groundcovers is the perfect way to spruce up your garden.
Below, we’ve revealed the best way to grow big and beautiful ferns in your garden.
1. Knowing When and Where to Plant Your Ferns
Given that ferns love the shade, planting them in an area with enough dappled shade and moisture is perfect. Some species of fern plants can tolerate partial sun. However, it’s wise to compensate for the additional heat by regularly watering them.
Ideally, place your ferns under a canopy of trees or near shrubs. By doing so, you’ll protect them from strong winds and increase the surrounding humidity levels.
As for soil, you should plant your ferns in an area with moist but not soggy soil. Also, ensure the soil is neutral to alkaline (or acidic, depending on your variety). The best soil for ferns is rich in organic matter with a high leaf mold content.
We recommend that spring or fall is the best time to plant ferns. Planting ferns during these growing seasons allows your plants to settle in before extreme spells of hot or cold weather.
In temperate climates, however, you could even plant your ferns all year round.
2. Preparing The Soil
Before planting your ferns, it is essential to enrich the soil first.
Apply a few inches of organic compost evenly over the soil’s surface. This will provide nutrients and enhance the structure of the soil. Then, mix your organic compost 8-10 inches deep into the soil using a rake or gardening tool of your preference.
Apply an added fine layer of topsoil, which will also help retain moisture.
3. Planting Your Ferns
Ideally, you want to dig a hole as deep as the fern’s rootball and twice as wide.
Use a garden fork to break up the base and sides of your planting hole if you have heavy soil. Breaking up heavy soils will make it easier for the roots to establish and ensure the fern has a good start to flourish.
Gently remove your fern plants from their containers, carefully easing out their roots. Be careful when transplanting your ferns so as not to damage the fern’s root system. Then, plant your ferns in their planting holes.
Add more organic matter and backfill the rest of the hole with soil. Gently press around the base of the fern to secure it and ensure there are no air gaps. Water thoroughly, but ensure that there is no waterlogging.
We recommend spacing your ferns at least two feet apart from each other.
When you’ve finished planting your ferns, spread a two-inch layer of organic mulch over your soil. You can use organic mulch like pine bark or leaf mold.
Whichever you use, organic matter will help the soil retain moisture, suppress weed growth, and keep the soil’s temperature cool. For added convenience in maintaining a weed-free garden, having a weed tool on hand can make the task much easier.
4. Caring For Your Ferns
To grow healthy ferns, it’s essential to keep the top five inches of your soil consistently moist but not waterlogged.
If natural rainfall isn’t sufficient, provide extra water for your ferns. We suggest watering your ferns every 4-5 days in summer and every 7-10 days in winter.
Tip: You can tell that your ferns need more water if they have brown, crispy leaves.
Regarding fertilizer, most ferns don’t need fertilizers to thrive. However, if your ferns aren’t growing as expected, you can use a well-balanced, slow-release fertilizer in spring.
Another consideration in caring for your ferns is to look out for pests. Fortunately, only a few pests, such as snails and slugs, affect ferns. Slugs and snails will attack your fern’s young fronds. To deter these pests, create a barrier of diatomaceous earth around your fern plants.
An alternative to diatomaceous earth is neem oil or insecticidal soap to rid your ferns of snails and slugs.
How to Make Ferns Grow Big: Tips and Tricks
Now you know how to plant ferns, you might want to know how to make ferns grow big and tall. Large ferns can create depth in all your planting schemes and are a great focal point.
To help you grow large, healthy ferns, we’ve assembled a few tips and tricks below.
- Repot your ferns into larger planters as this will encourage the plant to grow to fill the pot.
- Keep humidity levels at 50%, if possible.
- Fertilize your ferns once a month from early spring to mid-autumn using a slow-release fertilizer.
- Use room temperature water where possible to prevent temperature shock.
- Cut off any brown fronds.
- Add leaf mulch to the tops of the soil in your planters.
Use these tips, and our planting advice above, and growing lusciously large ferns will become much easier.
How to Grow Ferns: Final Thoughts
Now that you know how to grow ferns, you can decorate your living space with these stunning, versatile perennials.
Following the advice in this article will enable you to nurture healthy, strong ferns during their growing seasons. Remember to keep your ferns moist and humid, and to tag us on social media with photos of your success at growing ferns.
For more advice relating to plant growth and care, check out our blog!
Frequently Asked Questions
Our most frequently asked questions relating to ferns.
1. How long can you store fern spores?
You can store fern spores until you’re ready to sow them, provided that you keep them cool and dry. Under these conditions, you can store the majority of fern spores for up to a year. However, some ferns have green spores. These green spores aren’t viable for long and should be sown as soon as possible.
2. Do ferns like big or small pots?
Ferns grow to whatever size container you put them in. In other words, if you want to raise bigger ferns, plant them in larger pots.
3. Will my ferns survive winter outside?
Most ferns that gardeners can grow/purchase are hardy and will survive outdoors during the winter. However, it’s common for gardeners to grow/purchase half-hardy or tender ferns, which usually grow best in containers. These should be brought indoors during the winter. Ultimately, it depends on the type of fern you intend to grow, so it’s always best to check plant labels before you purchase them.
4. Why are my ferns turning brown?
Several factors can cause your fern’s leaves to turn brown. The most common causes of brown foliage on ferns are overwatering, underwatering, sunburn, and a lack of humidity. To avoid this, it’s always best to plant your ferns in an area with indirect light and high humidity levels. You should also water your ferns every 4-5 days in summer and every 7-10 days in winter.