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How to Care for a Jar Forest? Practical Guide

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How to Care for a Jar Forest? Practical Guide

Forest in a Jar – a unique decoration that is gaining increasing popularity among nature lovers and home gardeners. This form of miniature ecosystem not only looks beautiful but also brings many benefits. Forest in a Jar is easy to care for, self-sustaining, and does not require much space. It’s an ideal way to bring greenery into your home, even if you have limited space.

In this article, we explore the world of forests in jars. We’ll talk about how to prepare for creating them, what plants to choose, and how to care for the miniature ecosystem to enjoy its beauty for a long time. We’ll also learn about the threats that may lurk in our miniature garden and how to deal with them.

Preparing to Create a Forest in a Jar

Where to Place the Jar Forest?

Choosing the right location for the forest in a jar is crucial for its proper development and beautiful appearance. Here are a few factors to consider:

Access to sunlight:

  • Forests in jars need sunlight for photosynthesis, but they should not be exposed to direct sunlight, which can scorch the plant leaves.
  • An ideal location is a windowsill facing east or west, where the sun shines for a few hours a day but not all day long.
  • Avoid placing the jar forest on the south side, where the sun is strongest.
  • If you don’t have access to natural sunlight, you can use artificial plant lighting.


  • Forests in jars prefer warm but not hot temperatures.
  • Room temperatures, typically ranging from 18-22°C, work best.
  • Avoid placing the jar forest near heat sources such as radiators or fireplaces.
  • Also, avoid exposing the jar forest to sudden temperature changes, such as drafts or open windows in winter.

Remember that each forest in a jar is unique and may have slightly different needs. Observe your plants and adjust care to their individual requirements to enjoy a beautiful and healthy miniature garden for a long time.

Choosing Plants for the Forest in a Jar

Now that we have prepared the perfect place for our forest in a jar, it’s time to choose the plants. Choosing the right species is crucial for creating a harmonious and lasting composition.

Characteristics of plants for the forest in a jar:

  • Small size: Plants for the forest in a jar should be small and slow-growing to avoid dominating the composition and hindering each other’s access to sunlight.
  • Moisture requirements: Choose plants that prefer high humidity, such as in a closed jar. Ferns, fittonias, mosses, ivies, peperomias, and small begonias work well in a jar forest.
  • Low light requirements: Jar forests typically do not have access to direct sunlight, so choose plants that thrive in such conditions.
  • Disease resistance: Choose healthy and strong seedlings, free from pests and diseases. Remember that diseases can spread more quickly in a closed jar.

Examples of plant species:

  • Ferns: classic plants for forests in jars. Their delicate leaves and feathery fronds add lightness and charm to the composition. Species such as nephrolepis, adiantum, and asplenium work well in a jar forest.
  • Fittonias: small plants with colourful leaves that fill the space in the jar well. They come in various shades of green, pink, and red, allowing for interesting compositions.
  • Mosses: an ideal way to add natural character to a jar forest. They come in various shapes and colours and help maintain air humidity.
  • Ivies: climbing plants that can climb decorative elements in the jar, creating a green curtain. Species such as common ivy and Hedera helix work well.
  • Peperomias: small plants with thick leaves. They come in various shapes and colours and are relatively easy to care for.
  • Begonias: flowering plants that add brightness and colour to the jar forest. Choose small varieties with compact growth.

Remember, these are just a few examples. There are many other plant species that may work well in a jar forest. Experiment and choose plants that suit your tastes and preferences.

Additional Tips:

  • Before planting the plants in the jar, it’s advisable to trim them gently to remove damaged leaves and stems.
  • When choosing plants, consider their natural habitat. For example, if you want to create a tropical forest, choose plants that prefer a warm and humid atmosphere.

Creating a Forest in a Jar

Step-by-step instructions:

  1. Preparing the jar: Thoroughly clean and sterilise the jar. Sprinkle a layer of ceramsite or gravel about 2-3 cm thick on the bottom of the jar. This layer will serve as drainage, preventing excessive water accumulation in the soil, which can lead to root rot.
  2. Adding activated charcoal: Sprinkle a small amount of activated charcoal onto the drainage layer. Activated charcoal will help absorb excess moisture and prevent mould growth.
  3. Preparing the substrate: Pour forest substrate into the jar. The substrate should be light and airy to provide the plant roots with an adequate amount of air. If necessary, moisten the substrate lightly by spraying it with water.
  4. Planting: Gently remove the seedlings from their pots and loosen their roots. Using a small shovel or stick, make holes in the substrate to the appropriate depth and plant the seedlings. Press the soil around the plants to secure them well.
  5. Decoration: Now it’s time to arrange our miniature garden! Add moss, rocks, roots, and other decorative elements to create a composition you like. Remember to leave some free space around the plants for them to grow freely.
  6. Watering: Gently spray the plants with water to moisten them. Avoid overwatering, as excess water can lead to root rot.
  7. Closing the jar: Seal the jar with a tight lid. In the first few days after planting, the jar should be tightly closed to maintain high air humidity and facilitate plant acclimatisation.

Additional Tips:

  • You can use different types of moss to create a more diverse composition.
  • Instead of rocks and roots, you can use figurines, glass balls, or other decorative elements that match your style.

Most Common Issues and How to Resolve Them

Terrariums, although seemingly innocent and easy to care for, can sometimes surprise with problems. The biggest challenge in maintaining this miniature ecosystem is the soil microbiological balance. Inside a closed (but also open) glass garden, a huge array of soil microorganisms (bacteria, protozoa, fungi) develops, which are crucial for its proper functioning. They decompose dead organic matter, mineralize organic compounds, and provide soil fertility. Our role (as creators and caretakers of gardens) is not to destroy or disturb these microorganisms. Most of them are essential and play a beneficial role in maintaining balance in the miniature ecosystem.

Disturbance of the microbiological balance can lead to a range of problems, such as mold, fungi, and pests. These phenomena negatively affect plant health and can lead to their death.

Mold on leaves or bark is a common problem, especially after planting. Combat it with a mixture of detergent and vinegar, gently removing the coating. Remember not to use strong chemical agents that could destroy beneficial microorganisms.

A fungal coating on the substrate is a more complicated issue. Replacing part of the substrate or watering with garlic brew can limit the development of fungi. In extreme cases, a complete garden overhaul may be necessary. However, remember that a complete replacement of substrate and plants is a last resort, which should only be used in exceptionally advanced cases.

Mushrooms, while not harmful to plants, should be removed before they scatter spores and lead to mass fungal growth.

Arachnids and cobwebs do not cause much damage, but it is worth mechanically removing the cobweb to maintain the garden’s aesthetic appearance. Plant leaves can be wiped with a solution of vinegar and detergent to get rid of any possible spiders.

Aphids appear rarely, but if they do, a spray with a natural insecticide can be used. Avoid using chemical plant protection agents, which may have a negative impact on soil microorganisms.

Fungus gnats are the most common problem in closed glass gardens. Combat them with yellow sticky traps, which will catch adult specimens. Regularly observe your terrarium and remove fungus gnats to prevent their reproduction.

Remember that a terrarium is a miniature ecosystem that requires careful maintenance. By providing the appropriate conditions for the development of microorganisms and plants, you can enjoy a beautiful and healthy miniature garden for a long time.

Additional Tips:

  • Regularly observe your terrarium and respond to any concerning symptoms, such as changes in plant appearance, the appearance of mold, or pests.
  • Use natural methods to combat pests and diseases. Avoid using chemical plant protection agents, which may have a negative impact on soil microorganisms.
  • If in doubt, consult with an expert who can help diagnose the problem and choose the appropriate treatment method.

By maintaining microbiological balance and providing appropriate conditions for plants, you can be sure that your terrarium will grow beautifully and healthily, providing you with joy and satisfaction in caring for the miniature ecosystem.



Caring for a Jar Forest: Watering and Humidity – Detailed Guide

Watering is a crucial aspect of caring for a jar forest, but it often raises many questions and uncertainties, especially among novice enthusiasts of this hobby. To dispel these doubts, let’s take a closer look at this issue.

Closed Water Circulation – Foundation of Care

The main principle of a jar forest is to create a closed plant ecosystem in which water circulates in a continuous loop. After the initial watering upon planting, moisture remains in the soil and air, condensing on the jar walls and dripping back into the substrate. This allows plants to absorb water from the air rather than the soil, making the jar forest exceptionally easy to care for.

Exceptions to the Rule:

Although the principle of closed water circulation is generally valid, there are situations that may require additional watering:

  • Leaky sealing: If the glass is not perfectly sealed, gradual moisture loss may occur, leading to plant dehydration over time. In such cases, occasional watering will be necessary to replenish the water deficiency.
  • Open gardens: In the case of open containers, such as terrariums or kokedamas, regular watering is essential to maintain proper humidity.
  • Signs of drought: Even in closed jar forests, signs of drought may appear, such as moss changing color to silver or substrate shrinkage. In such situations, gently watering the garden to restore water balance is necessary.

How to Water a Jar Forest?

If your jar forest requires watering, remember a few important principles:

  • Use a small watering can or syringe: Water the substrate gently, avoiding excessive soaking of the plants. Excess water can lead to root rot.
  • Use lukewarm, filtered water: Avoid hard water, which may harm the plants. Distilled water or filtered tap water is ideal.
  • Water sparingly: Even in the oldest gardens, moisture usually suffices and does not require frequent watering. Overwatering can be more harmful than beneficial.

Opening the Jar Forest – Carefully and Moderately

Opening the jar forest may be tempting to observe the plants or add new decorative elements. However, this should be done with caution, as sudden changes in humidity can harm plants accustomed to the specific conditions of the closed ecosystem.

  • Stabilization period: After planting, within 1-2 months, a stabilization period of humidity balance occurs. During this time, the garden may intensively evaporate, and it is advisable to slightly open it for 10-15 minutes to remove excess moisture.
  • Mature garden: Once the ecosystem has stabilized, opening the garden is not necessary, and even discouraged! Remember that prolonged opening can disrupt the humidity balance and harm the plants.

Jar forests are fascinating miniature ecosystems that combine the beauty of nature with ease of care. With the right knowledge and care, anyone can create their own small glass garden that will delight the eye for a long time.

Remember that the jar forest is not just a decoration but also a living organism that requires care and attention. By following the guidelines in this article, you can provide your plants with optimal conditions for growth and enjoy the beauty of the miniature ecosystem.