Transplanting a plant, shrub or tree has its science, because, if we do not do it properly, we can cause irreparable damage. Miguel Ángel Martínez Téllez and Fernando Ayala Zavala, professors at the Center for Research in Food and Development (CIAD), share tips on how to correctly relocate our plants.
The academics from CIAD's Coordination of Food Technology of Plant Origin explained that, although transplanting seems a simple task, it is the adaptation of a living being to a new environment, and the risk of causing stress is high. For this reason, they indicated, the most advisable thing to do is to follow the steps described below.
Choosing the best time
Like humans and animals, plants have cycles of growth, activity, and inactivity, so the best time to remove a plant is the season when growth is the most active - spring. In this season, most plants have active root growth and this will allow them to expand into a new location.
The reasons for transplanting can be diverse and include everything from aesthetic reasons when the plants are ornamental, to providing them with an optimal place to grow and bear fruit when they produce food.
The signs that indicate that a plant in a pot or container needs to be replaced are the following: the substrate or soil dries out very quickly even in cool seasons, the roots start to come out through the drainage and become entangled with each other and, most noticeably, the leaves and stems grow very slowly or stop growing, even when fertilized as recommended.
If any of these symptoms are observed, it is time to decide whether to keep the plant at the same size or to transplant it. If we decide to maintain its size without affecting its health, we can carefully trim the secondary roots (those that are not directly attached to the stems and surround the substrate touching the walls of the pot) and add new substrate. In case we want it to continue growing, it is time to transplant.
Preparation for transplanting
If we have decided to transplant, it is necessary to choose a new place or container. We need to choose the best substrate or soil, depending on the type of plant; normally for transplanting in pots it is necessary to use a mixture of substrate that allows good drainage while retaining moisture so that the plant is hydrated.
If the transplant is in soil, we must also make sure that it has good drainage and adequate water retention for the type of plant; for this, we have to make sure that it will have adequate light for its species, that there are no diseased plants near the new place and that it has the right size to allow growth. The diameter of the hole should be slightly wider than the diameter of the roots and the depth should allow the plant to maintain the same stem level as before.
How to remove
Before removing the plant from its place, it is preferable to choose a time of day with mild temperatures, it can be very early in the morning, in the afternoon, or on cloudy days. It is also preferable to water the plant and wait for about an hour before removing it. If the removal is from a pot, we can exert pressure around it to detach it from the roots and facilitate the extraction, holding firmly the container and the plant from the stem and pulling with moderate force until you notice that it is coming out. If the plant does not come out easily, we may have to break the old container to facilitate the process.
Remember that, if we hurt the secondary roots, we normally do not compromise their life, but we must be careful with the primary roots, which are the largest and which are directly attached to the stems.
If the extraction is from the soil, the general procedure is similar; however, we must know how the roots develop so as not to damage them; there are roots in the form of tubers, others extended and branched, others that grow downwards; this depends on the plant and we must investigate it before carrying out the extraction. If the new location is far away, we can use another container for transportation to keep the roots fresh, moist, and unharmed.
A new home
It is important that the plant is kept hydrated during the process of moving to its new home in order to minimize stress. Although it is preferable that the transplant is completed as soon as possible, sometimes times may vary, since we must make sure that the new place is ready.
For this we have to prepare the substrate with good drainage, nutrients, and adequate size to receive the new inhabitant; the process should be done in the coolest hours of the day to facilitate the transition. The plant will be placed in its new place and we will press slightly the substrate to support it, without compacting in excess, because we must allow the water and the air to flow towards the roots.
It will take several days for the plant to get used to its new home. During this adaptation period, we can help it and for this, we must know the conditions of origin in terms of irrigation, temperature, and light, because little by little we have to get it used to the new environment where it will live.
Even if it is considered a sun-resistant species, if it comes from a place where it did not receive direct light and the transplant is direct to the sun, it is likely to suffer stress. If we transplant in a pot a plant that was in shade and the new place has direct sun, we must expose it gradually to the sun's rays in the morning or afternoon, until increasing the time of exposure. If the transplant is in soil or in a very heavy pot, we can put a shade net to reduce the light intensity and temperature.
Warning signs during the adaptation process are wilting, yellowing, and leaf loss; when we notice any of these symptoms, it is time to check drainage, substrate humidity, light, and temperature and start the adaptation process again. If we have not damaged the main roots and we give the appropriate adaptation period after transplanting, the new inhabitant will grow healthy and will brighten up our garden, fulfilling its important role in our ecosystem.
Source: Miguel Ángel Martínez Téllez and Fernando Ayala Zavala, researchers of the Coordination of Plant-Based Food Technology at CIAD.