Growing plants in pots

Not everyone is lucky enough to have a garden. Potted plants allow you to bring nature into your home, but also to extend the pleasure on a balcony or even a terrace. In pots, plants are far from their natural growing conditions, the difficulty being to recreate them and to ensure the necessary contributions to their survival

A reasoned choice

The plant coveted in the garden center must correspond to the conditions of luminosity, heat and hygrometry of its future location. This way you will have more chances on your side for the success of its culture in pot. For example, it is useless to grow cacti in a dark and cool apartment or fuchsias in full sun on a south-facing terrace. The choice of the plant is thus crucial for the future success.

A suitable substrate

Growing in a pot means knowing the exact needs of each plant in order to choose the right substrate. A plant installed in the garden will have a huge amount of soil at its disposal, it can spread its roots as it pleases, deep or on the surface to find the necessary nutrients. This is not the case for our potted subject, which will depend on the quantity and quality of the substrate offered in a more or less narrow container. The key word is always the same: adaptation to the needs!

Always ask about the needs of the plant and compose its substrate according to its needs: very light by adding sand, very fertile based on potting soil and organic amendments, neutral, acid, limestone ... The same goes for the container: plants with taproots will need a very deep pot, while those with weak development will be satisfied with a half pot.

Controlled watering

Potted plants must always be watered more than the same species in the ground. Evaporation is much more important under these growing conditions, especially in the case of potted plants installed on a terrace sheltered from rainfall but exposed to full sun and drying winds. The roots are very quickly dry and surrounded by a container that heats up quickly, without regular watering the catastrophe will happen very quickly.

In apartments, watering should also be adapted. First of all to the cultivated variety, but also to the exposure and the heating method. The dry air emitted by electric heaters is harmful to most of the so-called "green" plants, which are often tropical plants that appreciate a high level of humidity. To compensate for the lack of humidity, you can install the greediest plants on large plates filled with clay balls that are kept constantly moist and baste their foliage twice a week. Be careful, however, never to leave stagnant water in the saucers after watering, as this could cause your plant to rot very quickly due to asphyxiation of the roots.

A regular supply of nutrients

As we have seen, potted plants quickly exhaust the few reserves present in the soil. To make up for this lack, there is nothing like a regular addition of adapted fertilizer during the growth period. For green plants, a fertilizer rich in nitrogen (N) is preferable, while for flowering plants the dose of potassium (K) and phosphorus (P) is more important. Always look at the N-P-K ratio on the package.

Create a beautiful spring planter

With the return of the warm weather, the desire to put flowers on your balcony is growing. Here are a few tips to create a harmonious and long-lasting planter that will keep you happy all season long!

Choosing plants

Faced with the abundant stalls of garden centers or nurseries, it is sometimes difficult to decide.

To make sure you don't make a mistake, find out the needs of the plants you want and check that they are well suited to the exposure of your balcony.

To create a composition, don't forget that the plants you choose must have roughly the same cultural needs to be grown in the same planter. So, avoid mixing plants that appreciate shade and a humid substrate with cacti for example, the result might be aesthetically pleasing but your planter would not last very long!

Colors and shapes

Always try to create harmonious compositions by using plants whose shapes and colors match, for this, consult the color wheel to get inspiration. You can also link flowering plants with ornamental foliage such as Dichondra 'Silver Falls' with its drooping habit and soft silver color that will soften a combination of red petunias and yellow coreopsis for example.

For a full sun exposure, the combination of white verbena forming a round cousin of flowers and a 'Black Tone' ipomea with dark purple drooping foliage will also be a good idea. You can also combine petunias and surfinias because there are many varieties, with single or double flowers and in all colors. This way, you can create a composition full of pep in red, yellow or orange shades, or a romantic garden in pinks and blues.

In the shade, think of drooping fuchsias and blue lobelias, which always make an impact when combined. The latter, in white, will go perfectly with purple or bright red New Guinea impatiens. Think of coleus, with their ever-surprising foliage, sometimes tricolored, and which give height to the background of the decor. Also include Indian mint in your compositions for its long cascades of fragrant leaves. Begonias also appreciate half-shaded exposures, just like the bacopas with which they can be associated. Thus a very double pink begonia 'Pendula' will do wonderfully with a bacopa with a soft lilac tint, add a white lobelia for its vaporous structure and you're done!

Choosing a container

Choose a nice size planter if you want to create an abundant composition. If the container is too small, the root system will gradually colonize the substrate, which will dry out too quickly and will be much less fertile. The plants will not be able to develop properly. It is therefore better to plan large!

The substrate

Choose a substrate adapted to the plants you want to grow. For flowering plants, choose a good potting soil containing slow-release fertilizer balls, which will nourish them as needed. However, do not forget to add fertilizer regularly after one month of cultivation, because nutrients are quickly depleted in pots.

Create beautiful planters

From mid-May, the risk of frost is over, garden centers offer you a vast choice of plants that allow you to create compositions with perennials, annuals, foliage plants, mixtures of colors and textures, flower shapes, plant origins.

Be creative! But before you start, here are a few tips to help you create beautiful planters of about 50 centimeters:

Choose a quality potting soil by asking for advice at your point of purchase.

Incorporate a slow-release fertilizer into the potting soil that will provide "food" for your plants all season long and make maintenance easier.

Explore the different types of planters available to you: enamel, plastic, terra cotta, zinc or, why not, wood. Try out the plants you have chosen in the planter before planting, to make sure your choices are right.

Place your plants in two rows, the first row being the place of choice for hanging plants and the second row being recommended for upright plants. This way, you have a front and a back row, and your planter becomes a 600 square centimeter mini-mass!

Always think of a plant with foliage, which highlights the flowering plants and gives more lightness to the association: Festucaglauca, Plectranthus, Helichrysumitalicum, Carexbuchananii, variegated mint, Helichrysum microphylla.

A touch of white is essential for very bright colors or too dark, it softens the whole and brings clarity.

Choose carefully the plants you associate: avoid associating a plant with a very strong development with a plant with a small development, otherwise the first one will take over the second one and you will obtain an unbalanced association. Ask your horticulturist or the department manager of the garden center for advice.

Think about the evolutionary side of the planter, it is not necessary to have all the plants flowering at the same time. Play on the early season to be able to discover other flowers during the season.

How to winterize an osteospermum in a pot ?

Originally from South Africa, the Cape Daisy is not a hardy plant, it can only stay in the garden in winter in regions where frost does not occur. Everywhere else it is advisable to grow it in a pot in order to winter it in a sheltered place to preserve it from one year to another.

A good cleaning

Everything starts with a good cleaning. Your plant has just spent a season in the garden blooming abundantly and offering a breathtaking spectacle under the sun. Because the flowers of the Dimorphoteca (another name for the Cape Daisy), only open in the sun, which is one of their particularities.

In autumn, it is time to cut off all the faded flowers but also to remove the dried or yellowed leaves. Clear the center by cutting off any stunted or criss-crossing stems and then prune the plant along the contour of the pot, which will save you space when storing.

As for the height of pruning, cut at about 15 cm from the base without worrying, your plant will branch out more beautifully the following spring.

Now, take care of the soil by removing all the plant residues present on its surface. Take advantage of this to pull out any unwanted weeds that may have invaded the plant to limit competition for water and nutrients with your plant during its wintering.

Then check the general health of the plant, even if the osteospermum is rarely visited by parasites. However, spray nettle manure as a preventive and natural insecticide. If you find traces of diseases or parasites, remove as many affected parts as possible, treat with plant purines and quarantine the plant, as it would soon contaminate all the other overwintered plants. Indeed, confined in a room, and even more so if it is heated, the plants have a hard time being protected by the natural predators of their parasites present outside. The heat provides a favorable ground for the development of dormant larvae: beware!

Once the cleaning of the plant is done, let's go to the pot which can also shelter some snails or slugs hidden on the shady side or under the pot. Use a sponge with black soap and warm water on the outside of the pot. This will remove moss and tiny parasite larvae and eggs that may be hiding there.

Wintering osteospermum in a room

Choose a frost-free room to overwinter the Cape Daisy. If it is cold (not less than 5°C), it will endure it as long as it does not freeze and the substrate remains almost dry.

It is therefore unnecessary to water it and even less to bring fertilizer to it.

If you winter it in a greenhouse or heated veranda, water once every 10 to 15 days when the substrate starts to dry completely. Never leave water in the cup during wintering.

In the spring, when all risk of frost has been eliminated, bring your plant out again and gradually get it used to full sun. You will be able to water it again normally and to make a good contribution of dried blood and powder of crushed horn to see it starting again and blooming abundantly.

Taking good care of geraniums

Geraniums are the kings of the balcony. Let's see how to take care of them.

To take care of these plants, let's start by making an important distinction: in everyday language, the name "geraniums" often refers to plants that actually belong to the Pelargonium genus. Used on balconies in pots or window boxes, they are not very hardy and need to be kept frost-free during the winter.

Geraniums are perennial plants, their aerial part fades and disappears in winter; most of the real geraniums resist to -15°C, they are hardy, solid, very easy to maintain and allow the creation of imposing massifs over the years.

These two very distinct species belong to the Geraniaceae family. 

Pelargoniums

They are the kings of balconies: used in window boxes, the ivy varieties with beautifully cut foliage offer cascades of flowers that are constantly renewed throughout the summer. The zonal pelargoniums will be used in pots for their upright habit and their wide and rounded foliage often marked with a very characteristic dark zone. Many hybrids with white, cream, pink or yellow variegated foliage will bring a touch of originality to your pots. Fragrance lovers will not be left out thanks to the varieties with fragrant foliage that can be crumpled to give off surprising notes of mint, lemon grass, pine or even rose. Pelargoniums with large flowers are more fragile but nevertheless spectacular, forming magnificent bushy plants especially adapted to the culture in jars.

The growing conditions for Pelargoniums differ little: the soil must be very rich and well drained to avoid water stagnation at the roots which would rot the plant. A mixture of good potting soil enriched with fertilizing materials and light sand will suit them perfectly. The exposure should be very sunny and warm in a well ventilated space. The secret to obtain an abundant bloom lies in a very regular contribution of "special geranium" fertilizer (once a week) on a wet substrate so as not to burn the roots. The soil should only dry on the surface between two waterings and the faded flowers as well as the damaged leaves should be removed progressively.

You can easily take cuttings from your Pelargoniums in the spring by taking 10 cm long stems and rooting them in the shade in a mixture of sand and potting soil in equal parts. Never let this mixture dry.

As soon as the first cold weather arrives, put them in a ventilated and not very heated room, protected from frost. Reduce the watering to induce a resting period, and take them out only when the weather is fine and there is no risk of frost.

Geraniums

Geraniums are excellent bedding plants, and they thrive at the foot of shrubs, which provide them with soft, subdued light, good air humidity and the temperate temperatures they need. Plant them in rich soil to which you have added a nice amount of Brown Gold® at planting time. The soil should not dry out in summer, but should never be soggy. Contrary to pelargoniums, geraniums do not require any particular care and can even become invasive because they reseed themselves abundantly. Your only work will be to cut the faded foliage in early spring to allow the new shoots to develop well.

Feeding potted plants well

Plants grown in pots quickly use up the reserves that the substrate can offer them. This results in deficiencies and the plants are more prone to diseases and parasites. To avoid these problems, it is important to know how to feed them well.

A substrate always at the top

The root system of the plant lives in a restricted substrate when it is cultivated in pot. Contrary to a plant in the ground which can 'send' its roots deeper or spread them out at will, a potted plant can quickly be in pain and lacking in nutrients.

To overcome this problem, you must first make sure that the chosen substrate is of very good quality and corresponds to the real needs of the plant.

After a while, despite everything, the roots end up occupying the whole pot, it is then time to repot in a larger container, ideally in early spring. When repotting, add slow-release fertilizer balls to the substrate, or even crushed horn to facilitate the restart.

If the pot is too heavy or too large, you can consider a topdressing with good potting soil and compost to feed your plant.

Natural fertilizers

Throughout its growth, the plant needs to be accompanied. Natural amendments such as compost, coffee grounds or tea leaves will bring nutrients to your plants.

Purins are also very effective, especially nettle purin which really boosts vegetation.

Keep also the water of cooking of your vegetables which abounds in nutrients for your plants.

Finally, think of organic fertilizers to scratch every two months during the growth period, such as ground horn powder or dried blood, which work wonders without ever risking burning the roots or weakening your plants.

Chemical fertilizers

Chemical fertilizers have a 'kick-start' action because they bring nitrogen (N), phosphorus (P) and potassium (K) in rapidly assimilable quantities.

These fertilizers are divided into several families.

The best known are liquid fertilizers that are added to the water regularly (always after a very abundant watering to avoid burning the roots and respecting the doses). These fertilizers are dosed in a very specific way according to the targeted plants. The N/P/K dosage varies: for example, for green plants, the proportion of nitrogen will be more important to promote the development of foliage, while for flowering plants, phosphorus and potassium will be preferred. Fortunately, manufacturers have thought of everything and package their fertilizers under meaningful names such as 'Special fertilizer for indoor plants', 'Special fertilizer for geraniums' etc...

Liquid fertilizers also exist in foliar form, which means that they are sprayed directly on the foliage for an even faster action.

Another possibility is powder fertilizers, which will be diluted in the water or granulated fertilizers. These last ones exist in 'whiplash' version or in slow release in the form of balls or dice which are added to the substrate and which allow to be quiet during several months.