Care and maintenance
There’s a world of difference between a well maintained and cared for palm tree and some of the sad specimens one sees from time to time. We’ve never understood why someone would buy a beautiful and valuable plant and then kill it slowly over a number of years.
It’s entirely possible that many people have convinced themselves the particular palm isn’t suited to their environment and will always look that way. Having observed large healthy palms growing right next door to weedy and ratty palms of the same species it’s fair to say that’s generally not the case.
All that’s needed is a little care and attention. Below we’ve set out a few thoughts on how to keep outdoor palm trees looking in great shape year-round. We’re of course assuming that your palm tree is already in the correct location (see Planting a palm).
As a general rule make sure palm trees receive sufficient watering in the growing months (September to May) but also have good drainage. Stagnant water may cause roots to rot and wet ground takes longer to warm up in spring. When watering it’s generally best to provide a good soaking periodically (perhaps twice a week in dry spells) than a light sprinkling daily. This helps the plant to develop good, deep roots.
While practically all palm species that grow in New Zealand will appreciate good access to water during warm weather some species are particularly grateful and will reward you with fast and lush growth. These include:
Bangalow palm (Archontophoenix cunninghamiana)
King palm (Archontophoenix alexandrae)
Majesty palm (Ravenea rivularis)
Cascade palm (Chamaedorea cataractarum)
Himalayan Fishtail palm (Caryota maxima)
Juçara palm (Euterpe edulis)
For good growth and a tidy appearance it’s best to keep weeds at least two to three feet from the trunk of a palm. Once mature it’s generally safe to use a herbicide such as Roundup (although please read the suppliers' instructions and ensure that you spray on a calm day avoiding spray-drift on the leaves of the palm tree). For younger palms it’s best to hand weed.
Using a good layer of mulch around the palm will not only help to suppress weeds but also keep the ground moist and provide food for the plant. Do not however pile the mulch against the trunk of the palm.
To keep your palm tree looking good it’s necessary to periodically prune it. While this can be done at any time of the year it’s often most effective in late spring when new growth is appearing and old leaves are dying off. Since palms re-use the nutrients in their old leaves it’s best to wait until there is no green left on the leaf before pruning.
Prune the leave as close to the trunk as possible but in order to avoid scaring do not attempt to pull the leaf base off. Instead allow it to drop off in good time.
Depending upon your preference you may wish to remove fruit and flowers too.
We’re rather lucky in New Zealand in that we have few pests that can cause serious harm to palm trees. If you are fortunate enough to live in the bush you may need to take additional precautions but for most of us cutting off fruit to discourage birds and rats is about all that’s needed.
To maintain a healthy palm tree it’s important to fertilise regularly. This is actually a quick and easy task if carried out correctly. Below we’ve summarised the key points to be aware of:
Use a fertiliser with an NPK ratio of 3:1:3. Thus 9:3:9 or 6:2:6 et cetera is also acceptable as it’s the same ratio.
Slow release fertiliser is preferable as it works better and is safer for the palm. That said, a good fertilising regime may balance slow release with a boost in spring and be supplemented with organic fertilising during the year.
Whilst the bulk of the elements a plant requires are N (nitrogen), P (phosphorus) and K (potassium) they also require calcium (Ca), magnesium (Mg), and sulphur (S) as well as trace elements; boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), zinc (Zn) and nickel (Ni). For this reason use a fertiliser that contains ‘micronutrients’ or ‘microelements’.
Using slow release fertiliser we find it’s best to apply a small amount in spring, summer and early autumn.
When fertilising there are a few points to note:
Fertilise only when the ground is moist and water in well afterwards.
Avoid over-fertilising palm trees. This can be fatal.
Scatter fertiliser right around the base of the palm and out as far the distance that the fronds reach from the trunk.
Avoid getting fertiliser in the crown of the palm or in a pile against the trunk.