The Geraniums or pelargoniums are always a good option to embellish window sills, gardens as well as patios and balconies, all summer long, with their very pretty drooping or erect flowers. They also have an aspect often sought by gardeners; they have the ability to repel mosquitoes.
Common names: Geraniums or Cranesbills
Botanical name: Geranium
Botanical family: Geraniaceae
Plant type: Annual, biennial, and perennial plants
Sun: Part shade to full sun
Foliage: Palmately cleft leaves, mainly circular in form
Blooming: Five-petaled with distinctive veining, many colors (pink, purple, blue,…)
Height: 1 to 3 feet
Hardiness zones: 5 to 8
Plant origin: Eastern part of the Mediterranean region.
When to plant Geraniums?
Plantations are not necessarily done in the same way depending on the climate of your hardiness zone and the planting methods:
- If you are planning to sow Geranium seeds in containers or pots and you live in a region with a mild climate, you can sow them in March or April. Elsewhere you will have to wait until May.
- If you are planning to plant them outdoor in the ground, you must eliminate any risk of frost and allow the soil time to warm up. Plantations are not necessarily done in the same way depending on the climate of the region and the planting methods.
Choose the best Geranium for your garden
Geraniums include more than 300 species and 1,000 varieties. You never find the mention of species in store, because the Geraniums have been so hybridized that it would be useless.
Although, there are four main varieties:
Ivy leaved Geraniums or Ivy geraniums
They are used in planters and they are drooping.
It is used either as a ground cover, in suspensions or in a balcony because of its drooping nature. It exists in various colors.
They can be dwarf or not and have straight stems.
It gives flowers which can be single or double, white, red or pink colors. Its height varies from 1 to 3 feet, the dwarf varieties are from 6 to 8 inches. It is used in planters or in garden beds, its leaves are round with a dark ring. Some varieties have variegated or three-colored foliage.
Large-flowered Geraniums or regal Geraniums
Pelargonium grandiflorum: It has large, plain or bicolour flowers 2 inches in diameter. Its height is 1-2 feet, it is a shrub that is grown in the ground and its leaves are serrated and rounded.
Fragrant Geraniums or scented leaf Geraniums
Pelargonium tomentosum: It has a mint scented and white flowers, it can grow more than 1 foot.
The Pelargonium odoratissimum: It diffuses a scent of green apple and gives white flowers and it culminates at 2 feet.
Pelargonium capitatum: Its flowers are pink and it culminates at 2 feet and spreads a rose scent.
The Pink Geranium (Pelargonium graveolens): It gives off a scent of lemon rose and has small flowers with five pink petals and it is 4 feet high.
Pelargonium cordifolium: It spreads a spicy scent, one meter in size and pretty pink flowers.
How to plant Geranium seeds?
Before sowing your Geraniums, you must turn the soil over and dig it properly. You take this opportunity to remove weeds, roots, stones and other plant litter. Prepare holes about 7 inches deep depending on the size of the clods and incorporate leaf mold to the soil.
Tips to grow Geraniums in pots
- Use a pot or planter with drainage holes.
- Fill your container with Geranium potting soil with a little sand.
- Allow a space of 7 inches between the plants.
- Keep your potting soil moist after planting.
Tips to grow Geraniums in the ground
- Put your plants or seeds in the holes you have prepared
- Lightly cover the root ball.
- Fill your holes.
- Tamp gently.
- Water thoroughly.
How to propagate Geranium
Geraniums can be propagated two ways: by cutting or by sowing, the last is more difficult to succeed.
Rooting cuttings from Geranium
You cut them from August to September. Take a perfectly healthy Geranium:
- Remove with a pruning shear a healthy stem without flower and very vigorous. It should have 3 or 4 leaves and be 4 inches long.
- Shorten the stem a little and remove the leaves at the base.
- Fill buckets or a pot with sand or peat substrate or potting soil specially designed for cuttings.
- Water the substrate until the water is well absorbed.
- Plant the cuttings carefully so that they are not too close to each other.
- Close your container with a plastic bag or lid and place it in the shade or inside.
- After 8 to 10 days, you should have roots, and you can replant them in individual containers.
You can place them in open ground as soon as spring arrives. In winter, you keep them under shelter, dry and frost-free.
Growing Geraniums from seeds
Mid-January and mid-February are the most suitable times for sowing.
- Take polystyrene containers, they’re insulated.
- Put special potting soil for flowers.
- Place the seeds with a space of 1 inch so that the seedlings can grow.
- Cover with a light layer of soil mixture and sprinkle carefully with a sprayer so as not to disturb the seeds.
- Bring containers to light and above 65°F.
- A week later, the seeds start to rise. When the plants start to have four leaves, it will be time to transplant them into individual buckets.
After a month and a half, the plants are put back in their final pots:
- Pinch the terminal shoots to allow branching.
- Wait until early May to take them out.
Where to plant Geraniums?
Geranium is a hardy perennial that you typically plant in groups of 5 plants. It can perfectly be grown in the open ground, but also in pots, bins or planters.
In the open ground, choose well-drained and rich soils.
Caring for Geraniums
How to maintain Geranium plants?
Faded flowers: These will be cut very regularly just like the leaves that turn yellow.
Fertilizer: Potted Geraniums require weekly fertilizer inputs. Choose a liquid Potassium fertilizer to encourage flowers to foliage.
The Geraniums must be brought in in winter and protected from frost.
If you cultivate them in the ground, you rip them off the soil; remove as much of the soil as possible and put them in pots. You will keep them frost-free in a bright shelter.
Put them back in the ground or take out the planters when it is no longer likely to freeze.
How to water Geraniums?
In winter, you will only water when the substrate is really dry.
For soil crops, you will only water during the first few weeks after planting.
The Geraniums grown in pots are watered when the earth dries. Otherwise, the leaves turn yellow, but this favors the flowering, so it is necessary to act sparingly. Water your plants preferably in the morning.
Geranium pests and diseases: What to do?
Rust and grey rot: They damage the leaves that need to be burned. Treat the whole plant with copper spray or sulfur spray at the first sign of disease.
The pests of Geranium: red spiders, snails and white flies.
They usually attack during the hottest periods. Black slugs love young shoots and attack them preferably in the fall.
To eliminate white flies: Water the foliage.
For snails and slugs: Set beer traps.
Red spiders: They will be treated with an Acaricide.