How to keep geraniums blooming – 5 expert tips for maximum flowers

Want a plant that won't let you down, combines flower color, and will work in just about any soil and site? Geraniums are the answer, and if taken care of properly, can keep blooming all year round.

Hardy geraniums, also known as cranesbills, are one of the United States' most popular drought-tolerant flowering perennials. They are often used as groundcover and as partners for other perennials; they intermingle well with shrubs and roses; most are very well-behaved and many are so easy to grow that it's possible to build up quite a collection in no time at all.

The American Horticultural Society describes the cranesbill as 'the most popular of all hardy perennials: invaluable components of bed, border, and ground cover plantings in sun or shade.'

These reliable stalwarts for the border offer value for money and a beautiful display year after year. And there's so much choice. Hardy geraniums come in a range of flower shades, from the palest white, through every hue of pink and purple, to the darkest violet. They also offer a good selection of heights – there are low-growers at 4 inches high, which make excellent groundcover, or more vigorous options that reach 40 inches tall and make a real statement. And it's not just the flowers that add impact, the foliage is attractive, too. As if that all weren't enough, they are low-maintenance, rarely bothered by pests but brilliant for attracting bees. You can even, with some insider secrets, keep geraniums blooming every year. Have no doubt, the geranium is the ultimate wonder plant. It won't let you down.

How to keep geraniums blooming 

Learning how to keep your geraniums blooming comes down to a few important factors. We've spoken to the experts to get their verdict on keeping your hardy geraniums healthy and blooming all summer long. In fact, with just a few simple geranium care and maintenance tips, you can have beautiful blooms from late spring right up until the first frost of winter.

What cause geraniums to stop blooming?

If your hardy geraniums are looking a little lifeless, then understanding why is the first step to turning this seemingly dire situation around. 

If your geraniums are not blooming, the common culprits are usually a lack of sun, cold temperatures, frost, poorly draining soil, or too much nitrogen-rich fertilizer.

If you are after geraniums with a long-flowering season through late spring and summer into fall, look for varieties such as ‘Ballerina’ (pink flowers, purple veins), available at Monrovia, ‘Orion’ (clouds of blue blooms), Rozanne ‘Gerwat’ (blue, white-eyed), available at Nature Hills, and ‘Tiny Monster’ (magenta, dark veins), available from Monrovia. 

5 ways to keep geraniums blooming

Geraniums offer many options in terms of size, color and year-round interest. There are varieties to suit almost any site in the backyard, from hot, dry, sunny spots to damp woodland areas, and one of the toughest gardening challenges of all, dry shade. But if you are struggling to keep your geraniums blooming, then there are a few simple steps you can take to ease your way to success. We spoke to the experts to find out how...

1. Make sure your geranium gets enough sun

For the best-blooming potential, geraniums need sufficient sunlight (4 - 6 hours/day on average) during the summer. 

Bear in mind, too, that plants growing in extremes of sun or shade will perform better if you don't let the soil get parched.

2. Prune and deadhead to help your geranium bloom

Hardy geraniums will benefit from regular pruning and deadheading. After the first burst of flowers in the spring, you can cut the plant down by a third, removing spent flowers. 

Deadheading geraniums and light pruning will remove long stems that have fewer leaves and flowers. The fresh foliage that emerges will be healthier, stronger and support the development and growth of new buds.

3. Ensure your soil is well-draining

If your geranium is not blooming, it may be because of your soil. Geraniums, like most perennial plants, thrive in well-draining soil. Your plant may not bloom at all in soggy, waterlogged soil. 

You can make your soil drain better by introducing organic material. Good annual mulching with well-rotted compost, leaf mold, or organic matter, such as farm manure, will help keep plants thriving for a good few years.

4. Use fertilizer to increase blooms

More often than not, hardy geraniums do not need to be fertilized. However, if your plant is not blooming well, you can apply a balanced fertilizer once a year. Avoid fertilizers with high nitrogen content, and apply soluble fertilizers at half strength to avoid burning the plant.

It’s a good idea to water plants well with liquid fertilizer immediately after planting. For ground cover, amend the whole area where your hardy geraniums will be planted.

5. Divide an old plant

Another reason why your geranium may not be blooming could be because it is an older plant and may need dividing. 

The best approach, which suits most varieties, is to divide your original plants. Knowing how to divide plants is a simple process, and you don’t need to be an experienced gardener to tackle the task. Here's how: 

1. Dig up your plant in the fall as it is dying down, or in spring as it is starting to grow.
2. Pull the clump into pieces. If the crown is woody, use a hand fork or pruners to break it into pieces, each with roots and two or three shoots.
3. Replant these pieces and water them in. You an also use fertilizer at this point. They will soon develop into healthy new plants which will be exactly the same as their parents.