Gardenia is one of those plants that you can grow in pots or in the garden. Although due to its needs for water and land in which cases it is a bit demanding, the reality is that it is very easy to avoid problems, and also to solve them if they are detected in time.
Gardenia is an evergreen shrub native to East Asia. It is estimated that there are about 134 different varieties, among which stands out the Gardenia jasminoideswhich is the one that is usually found in gardens, patios and, sometimes, also inside homes.
To ensure that our plant is healthy, it is necessary to know its needs, which are:
Choosing a location for this plant is not always easy. Needs a lot of light, but not direct; This means that you should avoid putting it in a sunny place, but also in an area where there is total darkness. So where do we put it? I’ll tell you where I have mine: outside, in a pot under a black shading mesh that prevents 70% of sunlight from passing through it. If you have a site like this, or can adapt it, it will undoubtedly be very good for your gardenia.
However If you prefer to have it indoors, then you will have to find a room where there is a lot of clarity. Of course, it is important that you do not put it in front of the window, and less if it is oriented to the east since the sun will burn it when the magnifying glass effect occurs. Also, it should be away from the air conditioning and heating unit, as these dry out the tips of the leaves.
Gardenia doesn’t want a lot of water, but you also don’t have to let the soil sit dry for many days in a row. As usual, It should be watered about 3 times a week in summer, and once or twice a week the rest of the seasons.. Its roots fear both waterlogging and drought, as well as lime. If any of these problems occur, the plant will have yellow and / or brown leaves, no growth and, if it has flowers, these will abort and fall.
For this reason, clean rainwater must be usedwhenever possible. If there is not, a good alternative is any that does not have lime, or that has very, very little. The pH (or hydrogen potential) must be between 4 and 6 points; that is, it must be acidic. To find out what degree of pH the tap water has it is useful to use a digital meter, since you only have to put it in the liquid and wait a second or less for it to indicate it to you.
How to acidify irrigation water?
If the pH is higher than 6, it means that the water is alkaline. We could water with it plants that tolerate lime, such as rosemary, almond or rose bushes for example, but the gardenia would end up having chlorotic leaves due to its inability to obtain iron. And it is that, although the earth does contain this nutrient, when the pH is very high it is blocked; and of course, that way the roots cannot absorb it. From then on, the leaves begin to produce less and less chlorophyll (green pigment, which also intervenes in photosynthesis), leaving only their green nerves.
Fortunately, to lower the pH of the water we can do something as simple as adding a little lemon or vinegar. I say “a little” because the amount will vary depending on the pH. For example, I know that if I want to acidify tap water, which is very high, higher than 7, I have to mix 1 liter of that water with the juice of half a lemon.
Always, after each test, you have to check the pH, because if it drops too much, your plant would also have problems.
Land and transplant
Being an acid plant, can be planted in gardens with low pH soils (between 4 and 6). The time will be spring, since it is when it is growing.
If it is going to be grown in a pot, it is important to fill it with substrate for acidic plants (for sale here!), or with coconut fiber. Likewise, it must be transplanted approximately every three years.
A correct subscriber calendar will be very helpful for several things, such as avoiding chlorosis, making it grow healthy, and incidentally helping it to strengthen its defenses, which will be useful in the event that more ahead has any plague, disease, or is exposed to a sudden change in temperature. Indeed: The subscriber, who is nothing more than the extra “food” he receives, can save him a lot of trouble and damagein every sense.
But beware: an excess of fertilizer would mean the end of the gardenia’s life, since the roots would burn. Therefore, you must always follow the manufacturer’s instructions, and add only the amount indicated: no more, no less. The question is: Which one to use? Any of these that I will mention below; You can even use a month one and the next month a different one:
- Fertilizer for acidic plants: contains all the essential nutrients to ensure that the plant grows at a good rate and flourishes when it touches it, without missing anything. Buy it here.
- Fertilizer for green plants: it is thought to stimulate the production of leaves; hence it is very interesting to use it when the gardenia has little foliage. Get it here.
- Guano: it is a natural fertilizer; in fact, it comes from seabirds or bats. It is a VERY concentrated fertilizer, but also very effective. With a minimum amount, the plant is able to grow which is pleasant. You have it liquid (for sale here!) and granules (for sale here!).
- Homemade and / or ecological fertilizers: wood ash, worm castings (get it here!), mulch, compost, … Add a little from time to time to make it beautiful.
At first Only branches that are dry, diseased and broken after flowering will be removed. If you want, you can also remove or trim those that have had an exaggerated development, so that it has a compact demeanor and a denser crown.
Use anvil pruning shears, previously disinfected with pharmacy alcohol or a little dish soap. This will prevent them from contracting a fungal infection, something that is very common when tools are not cleaned before use.
Gardenia multiplied by cuttings most of the timesince it is simple and also takes root quickly. It can also be by seeds, but it is more difficult. Let’s see how it is done:
- Towards the end of winter / early spring, a semi-woody branch about 10 centimeters long has to be cut with a previously disinfected anvil scissors, and the lower leaves are removed.
- Afterwards, the base is impregnated with rooting hormones, or with homemade rooting agents.
- Next, it is planted in a plastic pot with holes in its base filled with coconut fiber.
- OPTIONAL, but highly recommended: so that fungi do not appear, it is advisable to pour powdered sulfur on the surface of the substrate.
- After watering, you have to cover the pot with a transparent plastic, like a greenhouse.
- Finally, it must be placed in semi-shade, in an area where the temperature remains between 20 and 25ºC.
After about 15 days or so they will start to sprout. At that time the plastic can be removed.
- The seeds are sown in spring, first introducing them in a glass of water for 24 hours. After that time, you have to keep those that have sunk since they will be the ones that can germinate.
- Next, you have to fill a seedbed, such as a flowerpot or a forest seedling tray, with acidic plant substrate or coconut fiber.
- Then water conscientiously.
- The next step is to place one or two seeds in each pot or socket, and cover them with a little substrate.
- Now, add powdered sulfur to prevent fungus.
- To finish, you have to place the seedbed in a bright place but without direct sun.
If it goes well, they will germinate in about 20 to 30 days.
Gardenia can be attacked by: mealybugs, aphids y Red spider. These three parasites They feed on the sap of the leaves, especially on the underside; aphids are also found on flowers. Luckily, they are removed well with a little water and mild soap, or with diatomaceous earth (on sale here!).
They appear when you water too much or when the humidity is too high. If we see that it has spots or something similar to gray or white powder, then we can assume that it has fungus. Those that most affect plants such as gardenia are the phytophthora or powdery mildew.
To treat it you have to cut the affected parts, and apply systemic fungicide (buy it here!).
While we cultivate it, problems can arise. We no longer talk about pests or diseases but about cultivation errors, for example:
- Lower leaves yellow: probably due to excess watering. When in doubt, check the moisture of the soil with a meter or a wooden stick. If you have more water than you need, watering should be suspended temporarily, and treated with a broad spectrum fungicide.
If the plant is healthy, flowering and so on, the lower leaves are normal for them to fall off as they finish their cycle.
- New yellow and / or dry leaves: lack of irrigation. The plant has little water to send to the newer leaves, which are the ones that need it the most. Treatment consists of watering, of course. If the soil is very compact and is unable to absorb water, place the pot in a tray of water for about 30 minutes.
- Dry leaf tips: it may be due to excess ventilation. If it is exposed to the wind, or to the drafts, it can have a hard time. It must be protected.
- Chlorotic leaves: if the leaves have green nerves but the rest yellow, they must be fertilized urgently with a fertilizer for acidic plants, or irrigated with iron sulfate. To prevent it from happening again, the pH of the water must be lowered.
This plant resists up to -2ºCso if it is colder in your area it is necessary to put it at home or inside a greenhouse.
With this information you can grow gardenia without problems.