Often kept year round inside the house, the Yucca or Joshua tree is an outdoor plant of which many species tolerate our harshest French climates very well because of their great hardiness. Let’s find out how to care for a Yucca, under what conditions to grow it, when to repot it and what its water needs are.
Caring for a Yucca
Perfect for all lovers of almost indestructible plants, the Tree of Joshua has many advantages and we can welcome the low level of requirement in terms of maintenance.
He is satisfied with very few things when he is given a place in full sun, and that it benefits from a well-drained soil so that its roots do not bathe in water. It thrives without difficulty inshelter from the wind, in poor, stony or even sandy soil as long as water does not stagnate there. Yucca is indeed a xerophytic plant. On the other hand, a very clayey soil in which the water does not flow well is not suitable for it at all and can even be fatal.
The Yucca in pot appreciates a moderate misting in winter if it is located in a heated room where the ambient air is particularly dry.
During the growth period, it is necessary to add a dose ofliquid fertilizer in the irrigation water once every four weeks, from spring to late summer.
The Yucca does not tolerate drastic pruning. At the most, we can limit ourselves toleaf trimming the tip of which is dry and removing those that are withered, stained, damaged or aging. They are cut at the base to free the trunk. It is also necessary to cut the wilted stems after flowering. This applies to specimens in pots as well as in the ground.
As is the case with all the plants that are kept in the home, the Joshua Tree needs that its leaves be dusted from time to time with a simple sponge soaked in non-hard water. Specimens left outside are usually dusted off by the rains.
Parasites and diseases
This tough plant is insensitive to disease. Only those that are overwatered or planted in non-draining soil are at risk of being affected by fungal disease due to the fungus Phoma. We can then see brown spots of circular shape on the lower leaves. A spray of Bordeaux mixture helps prevent this disease, and in case of attack, do not hesitate to remove all affected leaves and then burn them.
Some parasites like mealybugs and the red spiders can infest these plants in dry weather or indoors when it is very hot, but a few mistings of soft water is sufficient, preferably to prevent their appearance or to dislodge them.
Conditions for growing Yucca or Joshua Tree
It is recommended to mulch the plant fairly generously when it is young, in autumn, so that it passes the winter without difficulty. A good layer of gravel or dead leaves is enough to protect the young roots from severe frost.
Some species are able to withstand temperatures of -15 ° C (Yucca elata), -18 ° C (Yucca brevifolia), -20 ° C (Yucca filamentosa), -30 ° C (Yucca baccata), or even -35 ° C (Yucca glauca), provided these plants are dry. At the time of purchase, do not hesitate to get information from an advisor available to customers in the garden center.
The less hardy species should be kept indoors, but under these conditions they will not flower. An Indoor Yucca should be placed in the light but protected from direct sunlight especially during the hottest hours.
Repot a Yucca
It is necessary to repot a Joshua Tree every 3 or 4 years, in the spring, in order to install it in a container a little more spacious than the previous one but not too much. As larger specimens are difficult to handle, they can remain in their pots provided care is taken to replace 30% of the old substrate by a mixture of 50% potting soil and 50% garden soil.
Yucca water requirements
If the Yucca is frequently given the nickname ” camel plant »This is not for nothing. Its roots store enough water to meet the vital needs of this plant. Because of this, a Joshua Tree grown in the ground can be left outside in extreme drought and full sun, conditions that it endures without blinking.
The young yuccas planted in the garden should be watered moderately if it does not rain, at the rate of once every 7 or 8 days, especially in summer and during their first two years. As for those grown in pots, they need to be watered twice a week if it doesn’t rain for a long time and if it is very hot. Otherwise, a little shower from time to time is enough for them.
As for the less hardy yuccas grown in pots and put back in winter, they are satisfied with a light irrigation every 10 to 12 days throughout the off-season, so that the substrate can dry out between waterings. On the other hand, it is necessary to stop the fertilizer applications.
It is not surprising to be able to admire in our coldest regions splendid massifs with an exotic appearance, that is to say where the number of sunny days is not very high and where the temperatures are very below 0 ° C. Plant yuccas outside is therefore an excellent solution to admire their stunning flower stems of more than 60 cm of height which they adorn themselves in adulthood. You just have to choose the hardiest species. Be careful, however, not to install a Joshua Tree in areas of passage because its tough leaves have sharp edges and very hard tips which are therefore very sharp.