Tropical Bonsai Winter Care

Tropical bonsai winter care can mean only one thing... bring your tropicals indoors. For very large specimens you can cover the bonsai warmly for short periods of time, but if you are growing a tropical in the states which receive freezing temperatures and snow, you will not want to leave the coverings over your bonsai for very long or they will still be damaged by lack of sunlight.

If you own a tropical or sub-tropical bonsai such as a Brazilian Raintree or a Fukien Tea you need to do your research on your variety and know in advance what temperatures it can and cannot be exposed to in order to prevent damage from occuring. During fair weather you can keep your bonsai outdoors but tropicals will have requirements for minimum temperatures you will need to maintain to avoid damage to your bonsai.

USDA Cold Hardiness Zones

The best idea is to know what growing zone you are located in and only purchase varieties which are suitable for your location. However, you can successfully grow species that are out of your zone by re-creating their natural environment and needs indoors. Creating a tropical environment which will keep your bonsai healthy and happy indoors can be attained through the use of humidity trays and indoor lighting.

Once you know the appropriate conditions for your species you can begin preventative care before the weather turns. Reduce the amount of fertilization and amount of nitrogen you feed the plant and allow the recent growth to harden off. Hardening off is when those new green branches begin to get their woody appearance. Think of this as your plant putting on a sweater!, this will help to insulate the branch from cold weather.

Evergreen, tropical bonsai do not go dormant however they do need a period of rest during the fall and winter months as they store up energy for spring and summer growth. In nature this happens naturally as rain amounts lessen and the weather cools triggering this natural process. You will notice that while your tropicals will continue to grow and put out new leaves the growth is slowed dramatically as compared to spring and summer growth spurts.

A tropical bonsai left outdoors in temperatures unsuitable for your species will cause leaf damage, could cause branch die-back and could also cause the trunk and roots to die (total plant death). A tropical bonsai cannot tolerate the same over-wintering that a deciduous bonsai would be given.

A deciduous species is a plant (tree or bush) that loses all of its leaves naturally in fall and winter, semi-deciduous lose will lose some, most or even all of their leaves and tropicals and sub-tropicals are primarily evergreens meaning they do not shed their leaves based on the season. Evergreens will shed their leaves year round as the leaves age and become less effective.

Understand that plants do not just pick up and move themselves in nature and when this happens by artificial means (human interaction), they will typically react by yellowing off some leaves in protest! Moving the bonsai to protected locations effects many factors including light and humidity. When bonsai are moved from one location to another they should be acclimated slowly to the new location which will decrease the stress on the bonsai.

Some tropical bonsai varieties will need to be protected at temperatures beginning at 55 F. and below. Many varieites begin requiring protection at about 45 F. Again, research your particular variety to know what it can tolerate to avoid damage. Be aware of expected changes in your weather and begin to acclimate your tree to a protected location at least one week ahead of permanent placement.

As your bonsai acclimates to its new location it may yellow off some leaves in protest to the changes. This is a natural occurance and some of this process is helpful to the bonsai as it adjust its new leaves to catch the best lighting. This is apparent when you move a plant and a few days later you notice that the leaves are turning to face the sun. When you see quite a bit of leaves yellowing, begin treating your plant as a "stressed plant" and adjust your care accordingly (see below).

Yellowing leaves and leaf drop can occur from 3 - 10 days from the stressful event. Generally you will know the extent of your damage within 3 weeks.

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