Jacob’s Ladder (Polemonium) – The Complete Guide

Endowed with spiritual symbolism, the lush flowering Jacob’s ladder stands out from the great mass of summer flowering perennials.

The path to the successful cultivation of Jacob’s ladder is less steep than a ladder, though. You will soon recognize the frugal undemanding nature of this charming flower.

Planting Jacob’s ladder properly

As a classic wild perennial, Jacob’s ladder favors fall as its best planting time. Alternatively, you can set the plant in the ground in April/May.

While preparing the nutrient-rich, moist soil to a fine crumb in a sunny location, soak the still potted root ball in a container with water.

Here’s how to proceed in an uncomplicated manner:

  • Dig small pits at intervals of 14-16 inches (35-40 cm) to mix the excavated soil with compost and horn shavings.
  • Unpot the young plant, insert it in the center of the pit and plant it up to the lower pair of leaves.
  • Press the soil with your hands and water generously.

A mulch layer of leaves or bark mulch contributes significantly to the growth and contributes as winter protection in the first year.

Care Tips

The path to heavenly flowering abundance is neither rocky nor steep because the care of Jacob’s ladder is limited to the following aspects:

  • Never let the soil dry out and water even in winter when there is a bare frost.
  • Fertilize monthly with compost from April to September.
  • Cut back to basal leaves after the first flowering.
  • Prune close to the ground in autumn or late winter.

Since the plant is frost resistant to -49 °F (-45 °C), no precautions need to be taken for overwintering. In pot culture, we still recommend moving it to a bright, frost-free winter location.

Which Location is Suitable for Jacob’s Ladder?

In the wild, the flower seeks a place in nutrient-rich meadows or along sparse woodland. The closer the location in the garden meets these conditions, the more effectively the plant plays to its picturesque strengths.

These location characteristics are ideal for Jacob’s ladder:

  • Sunny to semi-shady location.
  • Warm and preferably protected from the wind.
  • Humic, fresh-moist to moist soil.

The Right Planting Distance for Jacob’s Ladder

In order for the herbaceous plant to perfectly showcase its pretty pinnate leaves and bright blue flowers, we recommend these planting distances:

  • Growth height 12-16 inches (30-40 cm): planting distance 14 inches (35 cm).
  • Growth height 24-32 inches (60-80 cm): planting distance 16 inches (40 cm).

If you cultivate the flower in a balcony box, you can reduce the planting distance by 3-4 inches (8-10 cm) to create a lush appearance.

What Soil Does Jacob’s Ladder Need?

The mystical plant unfolds its summer flowering splendor in perfection if the soil meets the following requirements:

  • Nutrient-rich and humic.
  • Moderately moist to well moist, but without waterlogging.

In pots and balcony boxes, Jacob’s ladder thrives wonderfully in structurally stable compost-based potting soil.

Look for a product with as little peat content as possible, as this component tends to compact with frequent watering.

When is Flowering Time for Jacob’s Ladders?

The magnificent Jacob’s ladder does not restrict itself to a single flowering time. Since the plant has the ability to rebloom, it delights us with the first flush of flowers in May and June.

If you then cut back the withered flower stems to the foliage and administer a little compost, an equally lush rebloom will follow in September and October.

Pruning Jacob’s Ladder Properly

Mother Nature endowed Jacob’s Ladder with the potential to rebloom. For the flower to actually accomplish this floral feat, it requires pruning.

After the first flush of flowers withered, cut all stems down to the basal foliage. Here, remove only leaves that no longer appear healthy and plump.

In September and October, the plant will then delight you with repeat bloom. Just before the first frost, cut off the withered Jacob’s ladder near to the ground.

Watering Jacob’s Ladder

The water requirement of Jacob’s ladder is at a high level. Thus, the root ball inside should never dry out. If the substrate surface dries out, you need to water the plant.

During hot summer days, this may well be necessary twice a day. Always apply water directly to the root disc and avoid sprinkling. If bare frost dominates in winter, preferably water the plant on mild days.

Fertilizing Jacob’s ladder properly

A mineral-organic starting fertilization in March/April provides a noticeable boost to this year’s growth.

Subsequently, treat the flower with a portion of compost and horn shavings every 4 weeks. A nutritious mulch layer of leaf mould or bark humus is also readily accepted by the plant.

Propagating Jacob’s Ladder

The uncomplicated cultivation of Jacob’s ladder continues seamlessly in terms of propagation. Dividing the rootstock in the fall not only creates more specimens but at the same time helps to rejuvenate this magnificent perennial.

In addition, the mature capsule fruits contain 1 to 12 seeds that allow propagation by sowing. As a normal seedling, sow the seeds in February behind glass, put a plastic bag over the seed container and keep the substrate slightly moist.

Already after 2 weeks, the first cotyledons peep out, from which vital young plants develop until May.

Is Jacob’s Ladder Hardy?

If the plant received its autumn pruning, no further precautions need to be taken in the bed for wintering. The flower is so frost-resistant that even temperatures of -49 °F (-45 °C) do not bother it.

In pot culture, however, there is a risk that the root ball will freeze through. Therefore, wrap the container in bubble wrap and place it on a polystyrene board or a block of wood.

Small containers with a diameter of fewer than 12 inches (30 cm) should ideally be placed in frost-free winter quarters.

Good to know

At the sight of this blue-flowered plant, the association with a ladder to heaven is within reach. Since it appears that the stair-like arrangement of flowers and leaves invites passing angels to ascend to heaven, Christians see here a direct connection to the biblical ladder to heaven. In a dream vision, Jacob saw this ascent and descent between heaven and earth when he was on the run from Esau. Thus, the title Jacob’s Ladder was obvious for the perennial.

Beautiful Varieties

  • Purple Rain: A purple flowering variety with light purple flowers. The growth height is 12-16 inches (30-40 cm).
  • Stairway to Heaven: A premium variety with blue flowers and creamy yellow variegated foliage. The growth height is 12-16 inches (30-40 cm).
  • Lambrook Mauve: A filigree beauty with pinnate leaves and lilac flowers. The growth height is 20-24 inches (50-60 cm).