Plant globe thistle in May or June to achieve mid-summertime blooms that last throughout the fall.
After it blooms, globe thistle continues providing textural interest with attractive seed heads.
This plant likes dry, nutrient-poor soil and can thrive in hot and dry environments.
Neil Holmes / Getty Images
A closely related species, the Scottish thistle, is an invasive species to avoid.
This plant will tolerate some morning or afternoon shade but will grow leggy if shade conditions persist.
Soil
Ample drainage is imperative for the health of globe thistle.
TatyanaBakul/ Getty Images
This plant likes dry, rocky, or loamy soil with an acidic pH of 5.5 to 7.
If your landscape is heavy clay, try growing globe thistle inraised bedswith amended soil to improve drainage.
Alternatively, you could plant this flower in containers.
4FR / Getty Images
Water
Globe thistle’s long taproot enables it to survive even the harshest drought conditions.
Water newly planted globe thistle weekly during the first month to help the plant establish itself.
Then, water only if the thistle shows signs of drought stress, like wilting and brown foliage.
This plant is ideal for axeriscaped environment.
Fertilizer
Globe thistle, like its weedy cousins, likes nutrient-poor soil, making supplemental fertilization unnecessary.
In nutrient-rich conditions, this plant may grow leggy and flop, requiring staking.
Types of Globe Thistle
Different varieties of cultivated globe thistle provide a varied look in the garden.
Pair the blue globes of one variety with yellow daisies or rudbeckia for a contrasting color wheel scheme.
White blooms work well combined with almost any annual or perennial.
When pruning globe thistle, wear gloves since the spiny leaves and stems can hurt bare hands.
Occasionally, the flower heads become heavy, causing the plant to droop.
Stake the plant or cut the flower in its prime for interior bouquets.
Bag the flower heads and cut the flower stem at its base to prevent reseeding when deadheading.
In late fall, before winter sets in, cut dead growth to ground level.
It will readily spread on its own if you don’t deadhead the flowers.
However, thelong taprootof globe thistle presents some potting challenges.
Neither infestation will kill the plant, but you will notice the appearance of bugs and cosmetic degradation.
To treat it, a few blasts from the garden hose will usually reduce the population.
Perform this several times for best results.
Once the weather warms and the soil dries out, the situation should remedy itself.
Refrain from using pesticides on this plant.
Rabbits and deer also don’t seem to care much for grazing on this plant.
This fungus resides in wet soil and can only be remedied by drying the ground.
Prevent this condition by allowing your globe thistle to dry out between waterings.
How to Get Globe Thistle to Bloom
Globe thistle does not require extra care to bloom.
It should bloom when full sun and well-drained soil are provided.
Bloom Months
Globe thistle typically blooms from July to September.
However, months may vary depending on climate conditions.
If you have milder spring temperatures, it may even begin flowering in late spring.
How Long Does Globe Thistle Bloom?
Blooms typically last from midsummer to early fall.
What Do Globe Thistle Flowers Look and Smell Like?
Globe thistle flower heads look like spiky pom-pom balls on the end of tall stems.
The globes are about 2 inches in diameter and comprised of tiny star-shaped flowers.
Colors are usually blue, purple, or sometimes white.
The flowers have no scent.
Deadheading Globe Thistle Flowers
Deadhead spent flowers and use them indried flower arrangements.
Deadheading prevents reseeding, keeps the plant’s growth in check, and encourages rebloom.
Common Problems With Globe Thistle
Globe thistle is alow-maintenance, drought-tolerant plant.
Do not overwater to prevent this situation from occurring.
Like most thistle plants, the young leaves of globe thistle are edible.
The leaves of globe thistle are covered with fine, stiff hairs irritating to the touch.
The stems can also be prickly.
It is best to handle them with gloved hands.
