Plumbago – The sky flower

The well-known plumbago, or the flower of Sky, is one of the easiest and fastest ways to give a blue color to a monotonous garden, terrace, or balcony.
Plumbago gained its nickname from all the shades of sky blue colors its flowers have.
Many gardeners and plant lovers combine the aetherial blue of plumbago flowers with the pink and red flowers of the bougainvillea and plant them side by side, either in soil or in pots.
Plumbago (Plumbago auriculata, Plumbaginaceae) is a perennial plant native to South Africa. It is intensely climbing, so we will often see it taking advantage of another tree or fixed point (e.g., fence) and sometimes reaching a height of more than 4 meters (13 feet). For this reason, and due to the vigorous vegetation it produces, plumbago is often used as a natural fence providing privacy in a yard. We can also exploit it to cover sloping terrain.
Plumbago is one of the “Plant and Forget” plants due to the minimum care needed to grow. As a result, it is a plant ideal for beginners gardeners. It is an evergreen or a semi-evergreen plant depending on the environmental conditions. In several areas, with mild winters and temperatures that rarely drop below zero, the plant keeps its leaves all year round, and in some cases, even bloom at that time.
Plumbago can also grow nicely in a pot. In this case, it can be a colorful addition to our balcony serving at the same time as a beautiful natural fence.
To grow in a pot, plumbago that will thrive and bloom for several years, we need to follow the steps below:

Buy a Plumbago plant

We start with purchasing plumbago from the plants nursery of our neighborhood in late spring and early summer. The price of 3 medium pots with 1-1.5 (4.9 feet) meters tall plants costs around 22 euros (25 dollars).

Pruning

After buying our plumbago, the first thing to do is clean it by removing the dry vegetation and withered flowers, using pruning shears. First, we cut until the previous branching all the mature flowers, which have begun to senescence. That way, we will help the plant concentrate its resources and its valuable nutrients into fewer but more beautiful flowers and young buds that will surprise us very soon with their appearance and colors. The pruning shears we will use during the deadheading must be of high quality and accompanied by the corresponding certificates.

Transplanting

Immediately after the first light pruning, we need to transplant the plumbagos into larger pots, ideally made from terracotta. Unlike plastic, this material has pores and helps decrease excessive soil moisture. Of course, regardless of its material, we need to open holes at the bottom of the pot allowing drainage of the extra water within a few minutes.
Plumbago does not have any special requirements regarding soil. We can choose potting soil that provides good drainage, and we can mix it with river sand, adding a little compost at the end.

Selecting the best Location for our Flowerpot

As in many ornamental plants, we need to select an appropriate spot to place our pots. If the area is not sunny enough and does not have direct access to sunlight for at least 6 hours a day, our plumbago will produce fewer and lower quality (cachectic) flowers. In this case, the green vegetation will prevail over the flowering. We should also be careful to choose a protected spot (leeward), as strong winds will scatter its delicate flowers.

Fertilization of Plumbago

When plumbago grows in pots, instead of the soil, we might need to add some nutrients. Fertilization has a crucial role, especially during the period from spring to summer. It is best to use a water-soluble NPK fertilizer 7-7-7 or 10-10-10 every six to eight weeks. The exact dosage is reported by the manufacturer in the label of the product, but usually, we dissolve a cap in 3 liters of water. The quantity of this solution is enough to water two large pots. We need to pay attention not to wet the leaves. It is best to do the last fertilization at the end of summer, but not later (autumn), as this may cause problems for the plant.

Plumbago’s Water Requirements – Irrigation Of Plumbago

Plumbago generally has moderate water requirements. Even during high summer temperatures, it can overcome stress caused by the lack of water for 2-3 days. As a general rule, in spring, it needs watering, on average, once a week, while during summer, it needs watering 2 to 3 times a week. It is good to water it only after we check the soil of the pot with our fingers and find that it is completely dry.

Pruning our Plumbago plants

In plants like plumbago with accelerated growth and powerful climbing ability, pruning is essential. Pruning can serve as a way to shape the plant into a compact bush, encourage it to climb to a fixed point, or cover a sloping terrain. However, if we leave it completely unpruned to spread uncontrollably, it is going to be very difficult to restrict it again later. In any case, strict pruning occurs in late winter – early spring and will significantly bust vegetative growth and flowering of the next growing season. Plumbago will bloom vigorously for a few weeks after strict pruning, as this plant blooms in new vegetation. Do not be afraid to remove even large shoots from their base. Complementarily, we can perform pinching and deadheading throughout the growing season.
Transplant in a larger pot approximately every three years.
We start in the spring-summer of the first year with a relatively small pot (but bigger than the plastic we bought the plumbago in from the plant nursery). For example, the pictured pots we purchased from the nursery were 6-9 liters, and we transplanted them into 20-liter pots.
The change of pots, from smaller to larger, has to happen gradually, e.g. from the 20-liter flowerpot (usually 30 cm – 1 foot deep) to a 30-liter flowerpot (usually 38-40 cm – 1.3 feet deep) after 2-3 years.
If we follow all the above steps and principles, our plumbago plants will live for several years, and they will reward us with numerous colorful flowers.