With their allure exotic, palm trees or arecaceous are more and more frequently cultivated in regions where they were not expected, and thus bring a somewhat unusual note to certain gardens. There are nearly 200 genera of palm trees, cumulating barely less than 3,000 species, all evergreen. Some of them are hardy enough to thrive in our regions with harsh winters while others, on the contrary, can only endure indoor life outside of summer. Every fan of the genre can therefore afford the Palm tree that best suits the chosen environment. Let’s shine a spotlight on the needs of palm trees in general, their planting and their maintenance.
Plant a palm tree
The palm tree is valued for the beauty of its evergreen foliage, that it is composed of fans, pinnate leaves, even petioles bearing thorns. It’s a matter of taste… It’s also their stipe which brings an original touch to our gardens, that is to say this pseudo trunk which takes shape little by little over the pruning. As for the flowering of the palm trees, it represents in a way the icing on the cake … Indeed, we must wait between 20 and 40 years old to see a palm tree bloom …
Planting the palm tree in the ground
It is from April to May that the best period of planting the palm tree takes place. He likes them sunny exposures sheltered from strong winds. In terms of land, the preference goes to soils in which water does not stagnate, therefore well drained. We can however note that some species of palm trees are even able to acclimatize to a dry, calcareous ground, but in order not to slow down their growth, these are not the ideal conditions.
Regardless, when buying a palm tree, in a garden center near your home or through an online horticulture site, it is essential to inquire well on its specificities in order to offer it the best growing conditions.
The planting a palm tree in the ground should be done as follows:
- Prepare the soil in the garden so that it is perfectly loosened: it is freed from stones, debris of all kinds, and weed roots.
- Dig a hole 60 cm deep and at least 50 cm in diameter.
- Prepare a mixture of 60% topsoil or that extracted from the planting hole if appropriate, 30% planting soil and three large shovels of organic manure.
- Place at the bottom of the hole the pebbles collected during the preparation, pieces of terracotta or gravel that we mix with pozzolana to ensure good drainage.
- Put the palm tree bought in a container in a basin of water in order to rehydrate the root ball.
- Place some soil on the drainage layer.
- Take the palm tree out of its container and gently untangle its roots so as not to damage them.
- Place the palm tree in the center of the hole so that the surface of the root ball is level with the ground.
- Recap with the rest of the soil / soil / manure mixture.
- Pack well.
- Water copiously.
It is recommended mulch the foot of the palm tree grown in the ground in order to limit the development of weeds and to maintain sufficient humidity. The mulch can be mineral, consisting of pozzolana, pebbles or colored gravel for example, or else vegetable as is the case with cocoa pods, flax bark and flakes.
Palm tree planting in a container
We choose this type of culture for tropical species poorly adapted to outdoor life in most of our regions, knowing however that any palm tree can be cultivated in pots. For those most sensitive to the cold, it is advisable because it provides shelter for its tropical tree in winter. Thus, we can opt for a bin on casters to facilitate movement, from a bright room or from the house to the terrace, ideal place to spend the beautiful season outside without difficulty.
Here’s how to plant a potted palm tree.
- Prepare a substrat composed of:
- 40% special planting soil or soil for Mediterranean plants,
- 30% good garden soil or topsoil,
- 15% compost,
- 15% pozzolana or clay balls (or half / half).
- Choose a pot full perforated and sufficiently large, 50 cm deep and in diameter,
- Place a layer of the mixture at the bottom of the tray,
- Place the palm tree in the center of the container after soaking the root ball in a bucket of water to rehydrate it,
- Fill the pot with the rest of the substrate and ensure that it seeps well into the root block,
- Pack all around the foot without hurting the roots,
- Water copiously.
One or two dripping feet can be stuck in the ground, which will maintain sufficient freshness if it is very dry, which will promote the rooting of the palm tree.
Growing a palm tree
In France, cultivating a palm tree in the ground is only recommended for hardy species when living outside Mediterranean regions or certain areas of the Atlantic coast protected from prevailing winds and frost. It is therefore better to choose a palm tree capable of withstanding negative temperatures. Small special mention for the species Rhapidophyllum hystrix, one of the hardiest once adult since it resists to -20 ° C in perfectly drained soil. But this is not the case with palms grown in pots because their roots are not well protected from heavy frost.
You should also know that it is quite possible to install an arecaceae near the house or the surrounding wall, its roots not risking damaging a building. On the other hand, we advise to hold it at a reasonable distance from a swimming pool in which chlorine is used, in order to protect it from splashes which may harm it.
Maintain a palm tree
The palm tree is easy to grow and undemanding.
The adult palm is drought tolerant. On the other hand, we plan to water it moderately but regularly. during the first 3 years during the driest times of the year. Under no circumstances should watering be excessive.
Throughout his growth period, a young arecacea needs fertile soil. If it is grown in the ground, care was therefore taken to amend the soil with manure when planting. But the palm tree pot deserves regular fertilizer applications. Also, from the end of March until October, we add to the irrigation water a liquid fertilizer for green plants or for shrubs in vats, scrupulously respecting the dosages clearly indicated on the bottle.
After a few years in its bin, the palm tree may need to be repotted if it seems too cramped. But for larger specimens, when repotting is a little too complicated, it is better to scrape the soil on the surface without injuring the roots and then eliminate it in order to replace it with a soil enriched with organic manure or compost. You can also simply add liquid palm fertilizer to enrich the devitalized substrate with essential nutrients.
It takes a few years before having to proceed with size of a palm tree, whether planted in the ground or in a pot. Only the very dry palms or leaves are concerned. They should be pruned in the spring, between April and June, using a lopper or, if the petioles are particularly tough, with a pruning saw. We cut as close as possible to the stipe, that is to say the sturdy stem which forms the false trunk of the palm tree. You have to wear thick protective gloves to prune thorn specimens.
Diseases and parasites
The palm tree is very resistant, although it unfortunately happens that it can seriously suffer from an epidemic of weevils that we nickname the palm killer because it causes the death of the subject in less than 24 months, as was the case in Occitania, the PACA region or even in the Toulouse area where hundreds of arecaceae have been decimated. This parasite is more precisely Rhynchophorus ferrugineus, red palm weevil.
A excess humidity can cause bud rot, as the palm under such conditions can also suffer from fungal disease. If this is the case, all affected leaves should be removed and then burned. Prevention involves limited watering and, above all, planting in draining soil. The sulfur and the Bordeaux mixture spray are good preventive solutions against all fungi that can affect the health of these plants.
Finally, they can fall prey to mealybugs, especially when the subjects planted in pots are kept all year round indoors in a hot and dry atmosphere. Therefore, it is strongly recommended to take out his potted palm trees so that they take advantage of summer rains.
In case of mealybug attacks, they can be sprayed with:
- A commercial anti-cochineal product,
- Nettle manure, very effective,
- A mixture composed of 2 spoons of black soap, 2 spoons of alcohol (at 70 or 90 °) and 2 spoons of vegetable oil which is diluted in 2 liters of water.
At the same time, we can try to remove as many mealybugs as possible. manually with a cotton ball soaked in 90 ° alcohol or even beer. It is then necessary to rinse with water in rather heavy rain then to pass the infested parts with a brush saturated with vegetable oil.
But be careful, you have to react as quickly as possible because if it is too infested (and this takes a short time), all the leaves of the palm tree end up drying out. In the most desperate cases, subjects infested with mealybugs are condemned. In addition, multiple plants can be contaminated, in the house as in the garden or on the terrace.