Winter Protection | Bonsai Learning Center


All dwelling issues require a relaxation interval. For people its eight hours of sleep per day. For timber, together with bonsai, its wintertime. This resting interval known as “dormancy” and refers to that timeframe during which the tree’s progress both slows down vastly or comes to a whole halt. Like a bear hibernating for winter, the bonsai’s vascular and mobile exercise is lowered because it begins to retailer up power for the approaching spring.

It may be a complicated and troubling time for bonsai lovers… nevertheless it needn’t be so. Understanding what is going on to the plant is the important thing to success.

Freshmen suppose that permitting a bonsai to freeze will kill it, (and within the case of tropicals, it’s true), however the overwhelming majority really need the chilly as a way to put them into “sleep mode” for the winter. In the event that they don’t get it, they’re like marathon runners who by no means relaxation. They start to decelerate and progressively lose vigor. Finally over time, they merely run out of power and die. That is what occurs to temperate bonsai that are introduced inside the home throughout the winter months as a result of their house owners worry that publicity to chilly climate will kill them. Offering right winter dormant circumstances on your bonsai will permit them the remaining which is important as a way to stay wholesome and completely happy.

Relying upon what a part of the world you reside within the provisions which you make for wintering your bonsai will fluctuate. Right here’s the way it works.

Some timber can face up to extra chilly than others. That’s to say, one selection is extra “chilly hardy” (or able to withstanding decrease temperatures) than one other. It’s frequent sense. There’s a motive that Japanese maples don’t develop in Miami Seashore and Palm Bushes don’t develop in Montreal. Should you don’t understand how a lot chilly your bonsai is able to withstanding, then the very first thing it is best to do is locate out. Head for the library or the web and make an inventory of the hardiness scores of all of the timber in your assortment.

The following factor to do is decide the minimal temperature vary for the situation during which you reside. The US Division of Agriculture has a chart ready which divides every part of the nation into local weather hardiness zones, primarily based on the historic low temperatures for that area. This data can also be available with a little analysis. How a lot winter safety it is advisable to give your bonsai shall be primarily based on the person timber chilly hardiness and on the local weather extremes during which you reside.

Insofar as chilly hardiness is worried, all timber could be divided into one in every of 4 classes:

Tropicals – These crops which have to be protected against freezing.

Semi-Tropicals – These crops which might face up to cooler temperatures and a average frost.

Temperate – These crops which might face up to prolonged durations in a chilly or frozen situation with out mobile injury.

Hardy – These crops which might face up to extremes of chilly (i.e. – sub zero temps) with out incurring mobile injury.


The transition of a bonsai from an lively rising situation right into a dormant state MUST be a gradual one. The method takes place usually and naturally because the cycle of the seasons progress. In summer time the tree grows and develops. As fall approaches, the timber progress and vascular exercise progressively start to decelerate and in winter the tree turns into inactive. As springtime approaches and temperatures start to enhance, the tree progressively awakens from its dormant state and begins to develop once more. Within the case of temperate and hardy bonsai this gradual transition into dormancy is primarily activated by temperature. Within the case of tropical and semitropical bonsai, the dormant interval is primarily activated by gentle as a result of winter days are shorter and winter sunshine is much less intense than summer time.

Tropical and Semi-Tropical Winter Safety

Bushes which fall into this class (i.e.- ficus, fukien tea, pomegranate, serissa, and so forth.) will must be supplied with winter safety when nighttime temperatures start reaching the 50 diploma vary. In no case, ought to they be allowed to freeze. Most can face up to a light-weight frost, however prolonged publicity to such chilly will definitely end result within the extreme injury or dying of the bonsai. In contrast to temperate and hardy crops, the expansion of a tropical bonsai does not come to a whole halt. They proceed to develop throughout the winter months, however their fee of progress is vastly lowered. Due to this, you need to present a wintertime atmosphere during which your tropicals can obtain the correct quantity moisture, humidity and lightweight.


The apparent reply to this drawback is a heated greenhouse with a local weather managed atmosphere. Additionally it is outdoors the price range of most bonsai practitioners. Most growers of tropical and semitropical bonsai convey their timber inside the home for the winter when temperatures begin falling under 50 levels. It’s the easiest and most price efficient answer to over wintering, nevertheless it comes with a number of issues which have to be addressed.


Gentle is the primary. Tropicals have to be positioned within the sunniest location doable. This may embrace a heated porch or a south dealing with window. Care have to be taken to rotate the timber regularly so that every one sides of the plant obtain an equal quantity of winter sunshine.

Moisture and humidity are the following two points. We preserve our houses dry within the wintertime as a result of it’s comfy, however if you happen to had been to try to offered the quantity of humidity within the air that your tropical timber would like, you’d have moss rising in your partitions. Holding the timber in a spare room together with a humidifier will definitely assist. If this isn’t doable, place the timber on high of plastic drainage trays that are stuffed with pea gravel and fill the tray with water. Because the water evaporates it would assist to maintain an envelope of moisture across the timber.

Take care to not set the pot straight into the water, as this could preserve the soil too moist and encourage root rot. Preserve a sprig bottle of room temperature water close by and mist the bark and foliage of the bonsai a number of occasions a day.

Likewise, if you happen to can not present a sunny window, you need to present synthetic lighting to compensate. Particular and infrequently costly develop lights will not be normally essential for bonsai. Plain 40 watt fluorescent lighting will do the trick, as long as the bulbs are situated inside three or four inches of the plant and are on for about 15 to 18 hours every day. Be looking out for insect issues as properly. A wide range of multilegged critters are keen on the dry circumstances in our houses within the winter time and can fortunately eat your bonsai if you’re not attentive.


Definitely sustaining bonsai in the home throughout the wintertime could be extra troublesome than wintering temperate timber outdoors, however tropical house owners even have the added pleasure of with the ability to take pleasure in their bonsai all yr spherical.

One of the crucial revolutionary options to sustaining bonsai indoors we have now seen got here from a good friend who used the bathtub in a spare lavatory to overwinter tropicals. He positioned an extended slim bench within the heart of the bathtub and hung fluorescent gentle on a timer above it. He saved about 2 inches of water within the backside of the bathtub to offer humidity and was in a position to shut the toilet door in order that the elevated humidity and lightweight didn’t disturb the remainder of the home. The commode, with the lid closed, turned out to be the right wintertime workbench and the sink was a prepared supply of water for the timber. The bathe head is also used to flush away insect issues if essential or simply give the timber a wintertime thundershower.

Necessity is the mom of invention and plenty of options to wintering bonsai indoors are doable, if you happen to simply remember that the crops necessities for gentle and water have to be met.


Overwintering Temperate And Hardy Bonsai

In over wintering temperate and hardy bonsai the target is to not defend timber from the chilly, however to ameliorate among the extra extremes of winter. They NEED the chilly as a way to emerge wholesome and completely happy within the springtime. On the similar time, nothing on earth is especially keen on 20 levels under zero or minus 40 under wind chill elements.

Most individuals will not be conscious that the basis system of a plant is rather more delicate to chilly than the highest of the tree. It is smart, when you consider it, nevertheless it additionally places bonsai at considerably of an obstacle in comparison with timber rising within the floor. Chilly can solely assault panorama crops from straight above. Nonetheless, a bonsai is in a pot, sitting on high of a rising bench. When the chilly comes it is not going to solely assault the roots from above, but in addition from all 4 sides of the pot. As a result of the pot is elevated on toes, it assaults the underside as properly. Due to this, a certain quantity of winter safety is prudent despite the fact that the bonsai is taken into account utterly hardy in your local weather zone.

At the start of chilly climate, temperate and hardy timber ought to be left on their benches and allowed to freeze a few times. This may trigger them to shift into dormancy. Deciduous timber will drop their leaves and evergreens will shift from the brilliant inexperienced they present in summer time to a steely blue inexperienced in winter. When you’re fairly positive that they’ve shut down for the winter, they must be moved right into a protected location. At this level they need to be relocated off their rising benches and moved into an space of the backyard particularly ready to offer winter safety. In northern climates this can happen someday simply earlier than Halloween. In southern climates they may must be put away round Thanksgiving

Publicity to the winter solar and wind can wither delicate branches and dry out buds. Bonsai ought to be moved to a shaded location out of the winter wind and solar. They are often nestled shut collectively on the bottom after which bark chips or oak leaf mulch could be positioned in-between the pots. They might even be buried straight within the floor, pot and all. This creates an atmosphere during which the chilly (because it does with panorama crops) can solely assault the basis mass from straight above.

The target is to not forestall freezing, however to cut back the every day repeated cycle of freezing at evening and thawing throughout the day had been it to be merely left on the rising bench. As soon as timber are “tucked in” for the winter, all you want do is water the timber and bark mulch completely and examine ever week or two to ensure they aren’t drying out. Since they’re dormant and within the shade, they may use a lot much less water than normal.

There are a selection of variations on this technique. Some growers place them below an elevated deck in the back of the home. Some preserve them in an unheated storage. Simply keep in mind that the target is to melt the blows mom nature offers us within the winter…. to not forestall them.


Winterization In Excessive Climates

For these of you who stay in additional northerly climates the overwintering process described above will solely be helpful for crops that you’ve got decided are hardy to your local weather zone. For temperate, however non hardy crops, you’ll have to create an atmosphere which gives sufficiently for chilly storage however is not going to allow the extremes of chilly that will usually kill that individual species. Such a tool is normally known as a “chilly body” and may take quite a lot of types.

Do not forget that in case your timber are dormant, they aren’t conducting photosynthesis and do NOT want gentle. Sure, this even applies to the evergreens. Holding them at nighttime for the winter is just not going to harm them. A chilly body is actually a field designed to accommodate your timber. It may be buried within the floor a few toes or sat on the bottom floor. It may be an enclosed space below an elevated porch; hooked up to the facet of the home; constructed inside an unheated storage or a field on a shaded condo balcony. It could be constructed out of brick, cinder block, plywood or plastic, as you select. Temperate however non-hardy timber ought to be positioned inside together with a warmth supply and a circulating fan. The target is to maintain this hermetic house as near freezing as doable all winter lengthy and to flow into air simply sufficient to forestall mould and fungus from forming within the damp atmosphere.

In case your chilly body is pretty massive, a reasonable house heater will do the job. If it’s a small house, the heat from a light-weight bulb could also be enough. Be sure the breeze out of your circulating fan doesn’t blow straight on the plant materials and desiccate it. Its a smart concept to buy a excessive/low thermometer so that you could see what the temperature variance is over a 24 hour interval. The target is to maintain the inside of the chilly body persistently simply above the freezing mark.

The primary factor to protect in opposition to in utilizing a chilly body is a field which will get so heated up when the solar is shining on it that it’s going to trigger temperatures contained in the field start to creep into the rising vary. This might trigger timber to return out of dormancy too early and undoubtedly end in a catastrophe. In extraordinarily chilly climates similar to Minnesota and Maine, all of the moisture freezes out of the air throughout the wintertime. If you’re working a chilly body in such an atmosphere you’d be properly suggested to mist the inside of the chilly body recurrently and maybe to maintain a container or two of water within the field as properly.



© 2000 Bonsai Studying Heart, All Rights Reserved


Author: admin

Leave a Reply

Your email address will not be published. Required fields are marked *