Geraniums (also know as Pelargoniums, or Storksbills) are drought and heat resistant plants with most species native to South Africa and can display flowers all year round in warm climates with the right conditions.
The reasons for geraniums not flowering are because of damp soil, too much shade, cold temperatures and high nitrogen fertilizer. Geraniums require well draining soil, potassium fertilizer, full sun and nightly temperatures consistently above 55°F (12°C) to bloom in the Summer.
Keep reading to learn why your geraniums are not flowering and how to implement the best practises for geraniums bloom to their full potential…
Over Watering or Slow Draining Soils Prevents Geraniums Blooming
Of approximately 250 species as 80% of all Geraniums (Pelargoniums) are native to South Africa where they flower almost all year in soil that tends to dry out somewhat due to warm weather and in between spells of infrequent rainfall.
Replicating the watering conditions and soil moisture of their natural habitat is important for plant health and to promote flowering.
Therefore, two common reasons for germanium not flowering are because of:
- Watering too frequently so that the soil remains moist or damp.
- Slow draining soils such as clay, or because of boggy low lying areas.
Damp, boggy soils can stress the geranium and cause fungal diseases such as root rot, which prevents effective root respiration and limits the germanium’s potential for flowering.
If your geraniums are not flowering, scale back your watering schedule so that the soil has a chance to dry out somewhat between bouts of watering.
Typically you should water geraniums in pots and containers once a week during the Summer, if there has been little rainfall and only water geraniums planted in garden boarders when there is a drought.
The important things is to adjust the frequency of watering (so that the soil has a chance to dry out) to suit your specific climate and the weather conditions.
To determine whether your geraniums require watering, test the soil to a fingers depth, if the soil is damp then skip watering for a few days but if the soil is beginning to feel dry then give the geranium a good soak.
If your garden soil is boggy, or slow draining because of clay or compacted soil then plant geraniums in pots, containers or hanging baskets to replicate the preferred dryer soil conditions which increases the geraniums chance of flowering.
Transplant any geraniums as a matter of priority if the soil is consistently damp to an area of full sun and well draining soil to increase the prospect of a good display of flowers.
Always water geraniums with a good soak as this encourages the roots to grow and establish in the soil and increases the plants resistance to drought.
Potted Geraniums Not Flowering
Geraniums thrive and flower exuberantly in pots due to the favourable drainage conditions, however it is imperative that your pot or container has drainage holes in the base for excess water to escape.
In pots and containers without good drainage, the soil becomes boggy and the plant either dies of root rot or becomes water stressed and does not flower.
This is particularly the case with indoor germanium as gardeners put a saucer or decorative outer pot to stop water draining out of the bottom of the pot and onto your furniture so always ensure water can flow out of the pot so that the soil does not become water logged.
For outdoor potted germanium I recommend a pot of around 12 inches across to ensure the pot has the capacity for enough soil and therefore nutrients for the geranium to flower.
In hotter climates a larger pot has the capacity to hold moisture and not dry out too quickly on baking hot days.
Applications of fertilizer become more important for potted geraniums to flower as the roots can exhausts the nutrients in the pot which reduces flowering.
Not Enough Sun for Geranium Flowering
One of the most influential factors for promoting germanium flowers is the amount of sunlight per day.
For stronger blooms, locate your geraniums in a location with around 6 hours of sun per day.
Too much shade causes geraniums to grow leggy, and display far fewer flowers.
Morning sun followed by afternoon shade is ideal for most climates and most cultivars of germanium for flowering and for a healthy plant.
In cooler climates such as the Pacific North West or the UK, geraniums flower best in full sun. whereas in hotter climates such as Southern California or the Mediterranean germanium can appreciate some protection from the searing midday sun, hence the preference for morning sun followed by shade.
If your geraniums are not flowering, move them to full sun if outdoors and to a sunny window indoors so the geraniums has the energy required for flowering.
Too Much Fertilizer Prevents Geraniums to Flowering
Geraniums are not necessarily heavy feeders so fertilizing too frequently or with too high concentration can promote foliage growth at the expense of flowers.
This is particularly the case with high Nitrogen fertilizers.
Scale back the use of fertilizer to; at the most once every 2 weeks with a well balanced general soluble liquid fertilizer ensuring the the ratio of Nitrogen, Phosphorous and potassium is even (10:10:10 NPK).
Once flower buds begin to emerge, geraniums display more flowers with a fertilizer that contains a higher concentration of potassium (as potassium encourages flowering).
Feeds for tomato plants contain a good amount of potassium and are great for promoting germanium blooms or you can use a specific product for geraniums available from amazon and garden centers which are higher in potassium to promote flowering.
Cool Temperatures Prevents Flowering
Geraniums can flower all year round in optimal conditions such as those in their native habitat of South Africa and only flower in cooler climates when the night temperature stays consistently above 55° F or 12° Celsius.
Therefore the reason your geraniums are not flowering may just be because it is too early in the season and they are waiting for warmer weather.
Once the weather does stay consistently warm geraniums can flower all Summer until the temperatures decreases in the Fall.
It is worth noting that a significant fluctuation in temperature can cause stress to geraniums, so moving a potted geranium from a warm house to the comparatively much cooler garden can cause shock which can prevent flowering.
Move geraniums outdoors for a few hours a day for around 2 weeks, gradually increasing their time outdoors to condition them to the contrast in temperatures and the geranium is less likely to suffer shock and therefore more likely to flower.
Keep in mind that geraniums are generally not frost tolerant and should either be brought indoors if potted or treated as a flowering annual plant in garden with cooler climates.
Soil Conditions Required for Geraniums to Bloom
Geraniums are drought and heat tolerant but they require particular soil conditions to thrive and flower to their best:
- Geraniums require a light friable soil to allow for root respiration and good drainage (geraniums do not tolerate damp soil). Amend the planting area with multipurpose compost before planting and avoid naturally boggy or damp areas of the garden.
- Heavy clay soils, compacted soil any slow draining soil is not favourable for growing geraniums and you should plant in pots, containers or hanging baskets instead.
- The more sandy or low in nutrients your soil is the more the use of fertilizer is required for geraniums to flower. An all purpose general fertilizer is suitable for geraniums, however once flowers emerge a high potassium fertilizer (such as tomato feed) promotes more flowers through the Summer.
In well draining light soil, amended with lots of compost (and with the use of fertilizer) geraniums are more likely to display a good amount of flowers.
- Geraniums do not display flowers if the soil is consistently damp, too much shade, high nitrogen fertilizer, cold temperatures or in small pots with limited nutrients.
- Geraniums require well draining soil, full sun, potassium fertilizer and consistent temperatures above 55°F (12 °C) at night to flower.
- Geraniums are from South Africa and prefer to soil to be somewhat dry between bouts of watering to thrive and flower.