A Step-by-Step Guide to Properly Watering Boston Ferns at Home

Welcome to our essential guide to watering Boston Fern plants at home. These tropical houseplants bring a lush jungle feel to any room, with their flowing fronds, lush green leaves, and a host of additional benefits. But for a Boston fern to thrive indoors, it needs specific considerations when it comes to watering. Here we’ll take you through the fundamental basics of when and how to water Boston Ferns at home.

When and How to Water Boston Ferns – The Essentials

Boston ferns are native to the humid jungles of tropical Africa and South America. Their growing medium must be kept consistently damp. During the growing season, water every 2 to 3 days with distilled, filtered, or rainwater when the top inch of soil feels dry to the touch. Humidity can also be maintained through misting or using a pebble tray.

The Role of Water in Plant Health and Development

Like most organisms, plants rely on water for survival. Plants need water for five main reasons:

  1. Cellular structure – Water makes up 80 to 90% of a plant
  2. Seed germination – Seeds begin sprouting when exposed to water
  3. Temperature regulation – Plants “sweat” water from leaves and stems
  4. Nutrition – Water helps the roots absorb nutrients properly
  5. Photosynthesis – Water, carbon dioxide, and sunlight combine to make a plant’s sugary food

What are the Typical Water Needs of a Boston Fern?

What are the Typical Water Needs of a Boston Fern?

Boston ferns need slightly moist soil at all times to keep them from drying out. Water Boston ferns more regularly in the spring and summer and less frequently in the autumn and winter. The trick is to avoid stagnant water in the potting vessel so ensure you have suitable drainage in place. 

To prevent contamination from chemicals, use distilled, filtered, or rainwater. Boston ferns also need high humidity, which can be achieved through misting or by using humidifiers and pebble trays. 

When Do I Know When a Boston Fern Needs Watering?

The easiest way to check if your Boston fern needs a drink is to test how dry the soil feels. Check this daily using your fingertips. If the soil feels a little bit dry, the fern needs water. 

Moisture probes can also be effective if you’d rather keep your nails clean and will also provide a better indicator of moisture content deeper in the soil base. 

The foliage can be a more drastic indicator. If the fronds are starting to yellow, the plant is parched and needs a drink.

How Often Should I Water a Boston Fern?

Boston ferns should be watered as often as necessary to keep the growing medium slightly damp at all times. Depending on your climate, this may involve watering anywhere from every 2 to 3 days or once a week. 

During the growing season, water at this frequency. In the winter, only water the fern every couple of weeks as growth will naturally slow during this period of dormancy.

What Type of Water is Best for Boston Ferns?

What Type of Water is Best for Boston Ferns?

Like most types of ferns, Boston ferns can be vulnerable to chemicals and salts in tap water. To avoid a sickly-looking plant, use rainwater if possible. If that’s not practical, then use distilled or filtered water. The latter is probably the most practical option for most Boston fern owners.

Make sure that any water you use is at room temperature because Boston ferns don’t like temperature extremes.

How to Water Boston Ferns

If your Boston fern needs watering, follow a few simple steps to avoid over or underwatering the plant.

  1. Always use a pot that has drainage holes. Water the fern thoroughly until water begins to drip out. Try not to get any water on the fronds themselves. Instead, aim for the soil around the base of the plant.
  1. To keep humidity high, it’s worth misting the fern every few days. Don’t get too liberal with the spray though as you want to avoid completely saturating the foliage. You can also place the fern’s nursery pot on top of a pebble tray with some water in it. The water will evaporate and raise the humidity.

What to Do In Between Watering Cycles?

What to Do In Between Watering Cycles?

Keep regularly checking your soil between waterings, especially in the spring and summer. Use your fingertip or a moisture meter to check if the top of the growing medium is beginning to feel dry. This tells you if the fern is ready for another watering cycle.

Never allow a Boston fern to totally dry out. This is a killer for the plant.

For more, see our in-depth guide on where to position Boston ferns in the home for optimal care and Feng Shui benefits.

Overwatering and Underwatering Boston Ferns

Boston ferns are extremely vulnerable to both overwatering and underwatering. Too little water will cause the fern to dry out and die. Too much water will initiate root rot. Keep an eye out for:

Root rot

If a bad smell starts to come from your Boston fern, check the roots. If they appear brown, mushy, and smelly, the roots are rotting. Cut off affected roots and let the soil dry out a bit before you resume watering.

Wilting fronds

This is usually a symptom of overwatering. If the fern’s foliage is drooping but the soil is still wet, there’s too much water in the soil. Let the soil dry out a bit and adjust your watering schedule.

Yellowing foliage

This could indicate underwatering or overwatering. If you see the leaves turning yellow, check the soil with your finger. If it’s soaking wet, avoid watering until the soil drys out a bit. If the soil is dry, water the plant thoroughly.

How to Water Propagated Boston Ferns

Boston ferns can be propagated by division or by using the running shoots that develop. Whichever method you use for propagating, keep the new plant’s soil moist but not waterlogged – just as you would for a mature plant.

Watering Boston Ferns After Repotting

Boston ferns typically need repotting every couple of years as the plant spreads. It’s a good idea to give the plant a quick water a couple of days before repotting. This makes it easier to transfer some of the old soil to the new pot. Once it’s been repotted, give the fern a thorough drink.

Wrap Up

Boston ferns may seem fussy when it comes to water. But by following a simple routine, you can ensure that your fabulous fern gets the right amount of water to truly thrive.

Only water when the soil feels slightly dry, especially in the spring and summer. Reduce watering frequency in the winter. Always use room-temperature distilled or filtered water.

Boston Fern Plant Care Guides:

For more, see our essential Boston Fern plant care guides:

Watering Boston Ferns FAQs:

Leaves that start to curl, droop or crisp up at the edges are common signs that your Boston fern plants needs watering.

Water liberally until you start to see water running through into the saucer underneath the pot. The exact volume will be dependent on the size of the Boston fern and the potting container. Aim to saturate the soil watering deeply so the full soil base receives some moisture.

A gentle mist can help to hydrate the leaves and provide a degree of humidity. Be careful not to saturate the leaves though as stagnant water on the surface can lead to decay and fungal infections.

As with all house plants and interior trees, the key is to find the right balance of light, water, and temperature. Every home or office presents its own unique set of circumstances so you’ll need to monitor and adjust to ensure your spider plant thrives. A happy, healthy Boston fern will display strong, healthy foliage and steady growth.

Boston Ferns can recover from overwatering if you’ve mitigated early and adjusted the watering cycles moving forward. Monitor closely over a 2 week period and observe for general signs of improvement in the plant’s overall health.


I’ve long been fascinated with the world of flowers, plants, and floral design. I come from a family of horticulturists and growers and spent much of my childhood in amongst the fields of flowering blooms and greenhouses filled with tropical plants, cacti, and succulents from all over the world. Today, my passion has led me to further explore the world of horticulture, botany, and floristry and I'm always excited to meet and collaborate with fellow enthusiasts and professionals from across the globe. I hold a BSc degree in Plant Sciences and have trained professionally at leading floristry schools in London and Paris.

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