Polemonium are hardy perennials that range in height from 15 to 90 cm.
They bloom from the end of spring to summer with blue, yellow, pink or white cup shaped flowers.
One of the common names for Polemonium is Jacob's Ladder.
Polemonium pulcherrimum by brewbooks.
The seeds of Polemonium can be sown outdoors at the start of spring or autumn; once sown lightly cover the seed. The plants should have a spacing of about 20 to 30 cm (small Polemonium species) or 45 to 60 cm (larger Polemonium varieties). They should ideally be grown in a partially shaded part of the garden that as a rich, moist soil that is kept cool and well drained, and has a pH of 5 to 8.
If you plan to first grow Jacob's ladder indoors then start about two months in advance. It should take about three or four weeks for the Jacob's ladder seeds to germinate at a temperature of 21 degrees centigrade. Once ready the young plants should be transplanted into the garden either at the start of autumn or just before the last frost of spring.
Jacob's ladder and other Polemonium species are fairly easy to care for; they like moist soil so water frequently. The soil should be kept cool, so it is best to top dress the soil with leaf mold in the spring. Once flowering has finished cut the flowering shoots back to ground level. If you require more Polemonium plants then they can be propagated by carefully division in the spring, or allow them to self and set seed in situ.
If you enjoy the information on this site, then you'll love my book: The Gardeners HQ Plant Growing Guide
It contains valuable information on How to Grow 500 different plant types in your Garden and sales help to support the GardenersHQ Website.
Download the PDF , MOBI (Kindle), and ePub (other readers and iPad) files and get a $1.00 discount by clicking here.
Check out our new Garden Products Reviews Section
Lawn and Maintenance