Bonsai trees have a kind of elegance and fragility that is the envy of anyone trying to grow plants indoors or out. But, for bonsai aficionado the cold months add their own unique challenges.
Bonsai trees grow slower or stop for dormancy in the winter months as many other plants do too and because of this, they require unique conditions to be healthy.
Whether you have tropical, subtropical or temperate bonsai species; the correct winter care for any style of Bonsai tree will help in securing your trees’ life over winter and keep them bursting with health come spring.
That means ensuring your bonsai trees are taken care of during the colder winter months, and in this guide we outline what you should be doing.
Know Your Waiting Period
Most bonsai trees, particularly temperate species such as juniper, maple and pine go through a dormancy period in the winter. A tree goes into dormancy for the winter as its growth slows or stops, a natural process that enables it to save energy and get ready to grow again when spring arrives. Meanwhile, the tropical and subtropical species do not go barren in a true dormancy sense yet they too require changes of care during winter time.
Dormancy Tips
Avoid overwatering: The water inputs of dormant trees are lower in the absence of growth. Allow the soil to dry out a little bit between watering’s, but do not keep watering in an attempt to get rid of root rot.
Do not fertilize: Your bonsai trees are dormant and will not be actively growing but in a state of rest, so no need to fertilize. Resume Feeding in the Spring when New Growth Begins to Appear.
Overwinter Outdoor Bonsai That Do Not Tolerate Frost
Protection from frost is important, particularly for an outdoor bonsai tree especially those that are temperate species. Although these trees have been designed to handle the cold weather, freezing can do a lot of damage on their roots while they are in so much hard work around.
Tips for Outdoor Bonsai Care
Move bonsai to a sheltered location like an unheated garage, cold frame or greenhouse. This protection enables them to over winter, which means they get a little period of dormancy from the cooler temperatures in those locales.
When wintering the plant, mulch at the base of it in order to insulate its roots. Consider using organic mulch such as straw or crushed leaves for additional padding.
Use frost cloth or burlap to protect bonsai from frosts and frozen winds on cold nights.
Monitor weather conditions. If a hard frost has been predicted consider taking your bonsai indoor for now but don’t put it in a heated room as this is likely to cause premature leaf break bud swell and flowers.
Tropical Bonsai: Interior; Adaptable to Low Light and Dry Humidity
Winter care in tropical and subtropical bonsai species is a different ball game since these trees will not tolerate the cold temperatures. This is the time of year when indoor bonsai need protecting from dry air created by central heating and their access to light reduced indoors.
Tips for Indoor Bonsai Care
Provide sufficient light: Place your bonsai tree in a bright spot of the house near to or Southern facing window. For a lesser count of natural sunlight, grow lights can be used to aid in less sun exposure.
Increase humidity: If the air is too dry, it may cause bonsai leaves to be brittle or brownish on their edges. To help counteract this, place a humidity tray with water beneath the bonsai pot or install a humidifier in the space.
Avoid temperature extremes: Avoid placing your bonsai near heating vents, radiators and drafty windows. Changes in temperature can cause a shock to the tree, which might result in leaf drop or poor health.
Be Vigilant in Your Monitoring of Irrigation
While your plant will have drops in how much it requires to watering throughout the year, this change is a lot larger if your bonsai tree is inside or out during winter. Irrigation in winter can be a problem for some people: the low temperatures slow down evaporation and, as temperatures drop at night time, radiative cooling helps wet conditions to extend longer; therefore it is not difficult that many variables end up by turning water into an enemy of irrigation.
Watering Tips
Before watering, check the soil moisture: Place your finger or moisture meter into the soil down to at least an inch to feel if it is dry.
Water less frequently: During winter, tree metabolism slows and it requires less water. However, do not allow the soil to dry out completely; this is particularly important for tropical species.
With indoor bonsai, use lukewarm water instead of cold water to avoid shocking the roots.
Winter Pest Control and Pruning
Winter is the time to check your home for signs of pest infestations, as this can still happen inside. Indoor pests such as spider mite, aphid and scale insects prefer the dry warmed conditions of your indoor spaces.
Pest Control and Maintenance hacks
Check your bonsai routinely for spider webs, sticky residue and small specs moving on the tops of leaves as these are signs that you have unwanted pests.
Kill pest by washing the infected areas with insecticidal soap or neem oil to avoid spreading of an infestation.
Prune dead or dying branches to keep the tree healthy, but wait until spring before performing any major cutting as this is when the growth process begins again for trees.
Patience is Key
Bonsai Trees—Be Patient This Winter Growth slows, and all may seem quiet but actually the tree is gearing up for a spring explosion of energy. However, resist over-caring for your tree by keeping watering to a minimum and refraining from fertilizing — keep an eye on light and humidity levels instead.
Conclusion
With the right care, bonsais can make it through the winter generally unscathed. Knowing about dormancy, being frost protective, acclimating to indoors conditions and monitor watering and pests will help your bonsai come back healthy next spring. By being patient and attentive, you can keep enjoying the beauty of this plant all year round!