Hardy Geranium, Meadow Cranesbill

Geranium pratense 

‘Boom Chocolatta’

PP32026

jer-AY-nee-um  pray-TEN-see

jer-AY-nee-um  pray-TEN-say

I found this Geranium pratense ‘Boom Chocolatta’ at Muddy Creek Greenhouse on May 10 in 2024 and had to bring it home. I really liked its dark leaves.

I needed a plant on the right side of the step on the north side of the house so that is where I planted the Geranium pratense ‘Boom Chocolatta’. I had planted a Colocasia ‘Coffee Cup’ here several times, but really wanted something that would return every year without having to over winter a rhizome in the basement. They would always rot and I would have to buy another one. It stays fairly damp over the winter in this location and even perennials I have tried here wouldn’t return the following spring. I was hoping this plant would do the trick…

I always like to do a little research and find out as much as I can about the plants I grow. Walter Gardens applied for the patent for Geranium ‘Boom Chocolatta’ in 2019.

The description on the Walters Gardens website says, “This perennial certainly does have a chocolatey look! This Geranium pratense hybrid has rich, dark bronze leaves and an upright habit, with blue-purple flowers covering the top of the habit, staring in early summer. Compared to older genetics, ‘Boom Chocolatta’ is more vigorous, and has a very refined habit. Use it as a contrast with green-leaved plants in your sun garden!”

First flower on 6-29-24.

According to patent record PP32026, Geranium ‘Boom Chocolatta’ was first hybridized by Hans A. Hansen of Walters Gardens in 2012. Mr. Hansen used Geranium pratense ‘Midnight Blues’ as the seed (female) parent and and the pollen (male) parent was presumed to be Geranium clarkei ‘Kashmir Blue’. Through diligent effort over a several year period, ‘Boom Chocolatta’ was selected from many other seedlings from the same cross and other crosses. Finally, after growing in Walters trial Gardens for two years, Geranium ‘Boom Chocolatta’ was offered to the public in 2018. 

USEFUL INFORMATION:
Family: Geraniaceae
Origin: Cultivar
Zones: USDA Zones 4a-8b (° F)
Size: 24-26” tall x 28-30” wide
Light: Shade to sun.
Soil: Poor to fertile well-drained soil.
Water: Average water needs. Can tolerate drought once established.
Uses: Use as a border plant, in containers, and would look great in mass plantings.
Needs: Cut back after flowering to encourage new growth.
Comments: I really like this plant with its dark leaves and blue flowers. It has done quite well next to the step.

This plant was a great performer in 2024 during its first year.

<<<<2025>>>>

I was really excited when I brushed back the leaves and saw the Geranium pratense ‘Boom Chocolatta’ had returned for 2025! We had a fairly mild winter which definitely helped!

No doubt I will take a lot of photos of this plant…

Even though cooler temps lingered, the Geranium ‘Boom Chocolatta’ continued to grow at a steady pace.

I noticed its first buds on May 22 in 2025.

How about a closer look…

By 5-29-25, it had quite a few flowers and continued to grow…

Geranium ‘Boom Chocolatta’ is adaptable to a variety of soils, preferring moderately fertile, moist but well-drained soil. Won’t tolerate water logging.

Geranium pratense ‘Boom Chocolatta’ (Meadow Cranesbill) on 5-29-25, #1047-4.Although reasonably drought-tolerant once established, it benefits from consistent moisture. Watering regularly during dry spells, especially newly planted specimens. Water when the top 1-2” of the soil is dry. 

Flexible and adaptable to planting location, north, south, east and west. Although they appreciate full sun in some climates, in areas with hotter summers they would do better with morning sun and afternoon shade. Otherwise, their leaves will burn in the hot sun. Mine is on the right side of the steps on the north side of the house where it gets good morning sun and shade by mid afternoon.

Most plants appreciate a balanced fertilizer every 4-6 weeks during the growing season. This supports robust growth and ensures flowering.

I have definitely not grown any Geranium like this one. I am so impressed!

Once the initial flush of flowers starts to fade (possibly July), cut back the plant by around 1/3. Supposedly, the plant will love it… I normally just deadhead…

Looks like it is winding down a little…

Although I haven’t had a problem with unwanted guests on my Geraniums, elsewhere they could be an issue. Always keep an eye out for aphids and other suspicious-looking critters.

I haven’t had any issues with powdery mildew or rust either, but in some climates they can also be a problem. Various problem occur when it is hot and dry and when it is cool and damp.

After a few years, you may notice your clump of Geranium ‘Boom Chocolatta’ has gotten a little larger. Being a rhizomatous perennial, they spread by rhizomes that can easily be separated. This will give you new plants as well as dividing overcrowded older plants. Overcrowded plants can sometimes lead to root rot,

The plant without the flowering stems was around 22″ tall x 30″ wide when the above photo was taken on 6-20-25. The top of the tallest flowering stem was 32″. I could get a better photo if it wasn’t for the old Achillea millefolium (Yarrow) which is another interesting story…

I looked for the largest leaf and found this whopper. It measured 8 1/4″ wide…

There are a lot of leaf stems (petioles)…

There are a set of leaves where the flowering stems fork. I don’t have to use technical botanical language since this isn’t a wildflower description…

Well, I have ran out of photos of Geranium ‘Boom Chocolatta’ for 2025. Let’s hope it returns again in 2026.

Sometimes I get busy doing other things and kind of neglect my duties with the flower beds. I have to make sure I plant forgiving plants that will be patient. I had no issues with the Geranium ‘Boom Chocolatta’ and highly recommend you give it a try. If you can’t find them at a local garden center, there are plenty of sources online.

To view my page for Geranium x pratense ‘Johnson’s Blue’, click HERE.

To view the page for Geranium sanguineum (Bloody Cranesbill, click HERE.

There are 2 native Geranium species growing on the farm as well, Geranium carolinianum (Carolina Crane’s Bill) and Geranium pusillum (Small-Flowered Cranesbill), which also have their own pages.

You can also visit my Geraniaceae page for links to all those above plus several Pelargoniums I have grown.

I hope you enjoyed this page as much as I enjoyed growing Geranium pratense ‘Boom Chocolatta’. Please leave a comment or a like if you can.

FOR FURTHER READING:
WALTERS GARDENS
PROVEN WINNERS
GARDENIA
GARDEN DESIGN
ROYAL HORTICULTURAL SOCIETY