Polemonium caeruleum, commonly known as Jacob’s ladder or Greek valerian, is a species of flowering plant in the Polemoniaceae family. This lovely plant is native to the temperate regions of Europe and Asia. It grows most often in rocky areas, woodlands, damp grasslands, and meadows.
Jacob’s ladder is more than meets the eye. Although this flower may seem very delicate and dependent, it is actually very hardy and low-demanding. Due to its infinite beauty and easy-going style, Jacob’s ladder has become a pretty popular ornamental plant worldwide, especially in regions that mimic its natural habitat.
Keep reading our guide to find out everything you must know about the friendly and low-maintenance Polemonium caeruleum a.k.a. Jacob’s ladder!
About Jacob’s Ladder
- Its common name “Jacob’s ladder” comes from the biblical story of a dream that the son of Isaac, known as Jacob, had. The dream consisted of a ladder that was leading to heaven. This name refers to the fern-like leaves of this plant that resemble the ladder.
- Jacob’s ladder comes with several different cultivars, giving you more interesting options to choose from. The most eye-catching varieties include ‘Album’, ‘Bambino Blue’, ‘Blue Pearl’, ‘Brise d’Anjou’, ‘Snow and Sapphires’, and ‘White Pearl’.
- The superb flowers of Jacob’s ladder are very fragrant. They are highly attractive to many species of common pollinators like butterflies and bees. Moreover, Jacob’s ladder is a wildlife-resistant plant, so you won’t have to worry about rabbits and deer munching on its leaves.
- In ancient times, mostly among Ancient Greek physicians, Jacob’s ladder played a big part in medicine. People used it as a treatment against various health issues, such as hysteria, swelling, fever, headache, palpitation, toothache, insect bites, or dysentery.
- Thanks to its generous versatility, this plant is a perfect addition to numerous landscape decorations. It will look absolutely fabulous in rock gardens, coastal gardens, city gardens, cottage gardens, beds, borders, and even in containers.
- Jacob’s ladder can make for a good-looking companion to other species of plants. Some of the most common companions are Columbine, Coral Bells, False Goat’s Beard, Lady’s Mantle, Oriental Poppy, Painted Lady Fern, Plantain Lily, and Torenia.
- Jacob’s ladder is one of those non-toxic plants that you can grow anywhere near your curious kids or furry friends without worrying about their general safety.
Jacob’s Ladder Features: An Overview
- This plant belongs to the Polemonium genus that contains about 25 to 40 species of flowering plants. It shares this genus with other stunning look-alike species including P. acutiflorum, P. boreale, P. carneum, P. eximium, P. pauciflorum, or P. reptans.
- Jacob’s ladder is a hardy flowering perennial. In general, this plant can reach from 12 to 24 inches (30-60 cm) in both height and width. However, some cultivars may occasionally grow taller than 35 inches (90 cm).
- Its foliage consists of many basal, mound-forming, fern-like, and finely divided leaves that grow on long, erect, stiff, and green stems. The leaves are usually dark green, but some varieties can come with green and creamy-white variegated leaves.
- Depending on the cultivar, the blooming period of Jacob’s ladder can last from spring through summer. During these seasons, it exhibits ravishing sprays or clusters of delicate, fragrant, and bell-shaped blossoms.
- Its flowers measure up to one inch (2.5 cm) in diameter. While they appear blue and purple on most specimens, some Jacob’s ladders can also show up with flowers in various shades of white, yellow, or pink.
Growing Jacob’s Ladder
When this plant looks so heavenly and it is so easy to grow and care for, you cannot possibly miss the opportunity to add it to your collection. Believe us, all you have to do for Jacob’s ladder to thrive is simulate the environmental conditions from its natural habitat at home.
In terms of lighting, the Polemonium caeruleum species and most of its varieties will grow at their best in partial shade to dappled shade. Keep in mind that those cultivars that have dark green foliage can withstand more direct sunlight than those that feature variegated leaves. However, all cultivars will handle this kind of exposure only if you maintain their soil constantly moist.
In general, Jacob’s ladder is fairly hardy and can tolerate both cold and hot temperatures from the USDA hardiness zones 4 through 9. Although this plant prefers relatively cool summer months, it can also do just fine if it receives high heat, but only in warmer southern areas.
Jacob’s ladder will not appreciate very humid conditions. In fact, too much moisture or humidity will stress out your plant, making it prone to different fungal diseases or pest infestations. Luckily, you can get rid of all of these issues if you take action in time.
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- LIGHT: Thrives in full sun or part shade. Best with protection from the hot afternoon sun, particularly in warm summer areas. Intolerant of high heat and humidity.
- SOIL: Thrives in average, medium, well-drained soils. Prefers fertile, moist soils. Do not let the soil dry out.
- TALL: Grows up to 12-24 in. tall and 12-18 in. wide.
- BLOOM PERIOD: Blooming in mid to late spring, the blossoms are borne atop dark stems and rise well above the foliage mound of finely divided, fern-like, dark green leaves flushed with purple-black.
- USES: A lovely plant for beds and borders, edging, rock gardens, cottage gardens, and containers.
Last update on 2023-07-28 / Affiliate links / Images from Amazon Product Advertising API
The most common pests that can bother your Jacob’s ladder are leaf miners and slugs. If you notice any of these intruders on your plant, handpick them, then remove the unhealthy parts. After this process, we suggest you apply neem oil or other suitable organic treatments to prevent future infestations.
Leaf spot or powdery mildew are among those diseases that can also affect the well-being of your Jacob’s ladder. The best way to avoid these infections is by providing your plant with good air circulation, watering it only in the morning, and keeping its foliage always dry. In advanced cases, you should apply a fungicide to prevent any possible spread.
Planting Jacob’s Ladder
Without a doubt, the ideal time to plant your Jacob’s ladder is early spring, but only when the last danger of frost has passed. In case you have more specimens, plant them at a distance of about 12 inches (30 cm) to avoid over-crowding them and ensure excellent air circulation.
When it comes to its growing medium, Jacob’s ladder does well in acidic to neutral substrates with a soil pH between 6.2 and 7.0. Still, this flower is pickier regarding other properties of its growing medium than about soil pH. If you want to give your plant the time of its life, plant it in a loose, well-draining soil that is rich in organic matter and nutrients.
Fertilisation-wise, Jacob’s ladder will perform best if you provide it with regular applications. The truth is that this plant will be your companion for a long time if you provide it with proper growing conditions and fertilizers. Feed your Jacob’s ladder with a balanced fertilizer twice every year. Make sure you are doing this first in early spring, then again once you cut back its faded blossoms.
Deadheading your Jacob’s ladder after its blooming period can cause another round of flowers to show up. Likewise, when the foliage of your plant becomes somewhat untidy, you can cut it back to make room for new, healthy growth.
If you want to grow your Jacob’s ladder in a pot, plant it in one that has drainage holes at the bottom. This flower tends to spread like crazy with time, so you will have to repot it eventually to secure enough room to develop. Once your plant begins to outgrow its container, we recommend you transplant it gently in another that is one size larger than the current one.
Watering Jacob’s Ladder
Watering-wise, Jacob’s ladder has moderate demands overall. This plant will show the best results if you provide it with regular watering all year round. As a general rule, a suitable watering routine will help your plant bloom for a longer time and also remain charming during the summer months.
Since Jacob’s ladder loves moisture but it is susceptible to root rot, you must always check its soil in-between waterings. When the top half of the substrate has dried out completely, this is the perfect time to spoil your flower with a nice drink. However, make sure you check its growing medium more often during the warmer seasons because high temperatures will typically dry the soil faster than usual.
Propagating Jacob’s Ladder
Whether you are a beginner or experienced gardener, the easiest and fastest way to propagate your Jacob’s ladder is by division. Still, make sure your plant has reached maturity before going through the process. This method is not useful only for making more spectacular plants, but also to keep your Jacob’s ladder alive for longer.
Jacob’s ladder will benefit from regular division once every two to four years. First things first, you will need to dig your plant out of its growing medium. After this step, carefully divide its roots into two or three parts, then replant each section in its permanent location.
Another way to surround yourself with more Jacob’s ladders is starting them from seed. Although this plant will self-seed on its own, you can also collect the seeds from the flower heads and plant them anywhere you want. For optimal results, make sure you sow the seeds in either spring or fall and loosely cover them with soil. If you maintain their soil constantly damp, germination will occur in a few months or so.
Now that you are more familiar with Polemonium caeruleum a.k.a. Jacob’s ladder, you are more than ready to att it to your plant family. Its alluring presence, versatility, and low-maintenance nature make this plant a must-have in every passionate gardener’s collection.
Do you already have one or more Polemonium caeruleum a.k.a. Jacob’s ladder plants around? Share your delightful journey with us in the comments!